WorldWideScience

Sample records for project neatcp meta-analyses

  1. Evaluation of the United States Department of Agriculture Northeast Area-Wide Tick Control Project by Meta-Analysis

    Science.gov (United States)

    Brei, Brandon; George, John E.; Pound, J. Mathews; Miller, J. Allen; Daniels, Thomas J.; Falco, Richard C.; Stafford, Kirby C.; Schulze, Terry L.; Mather, Thomas N.; Carroll, John F.; Fish, Durland

    2009-01-01

    Abstract As part of the Northeast Area-wide Tick Control Project (NEATCP), meta-analyses were performed using pooled data on the extent of tick-vector control achieved through seven concurrent studies, conducted within five states, using U.S. Department of Agriculture “4-Poster” devices to deliver targeted-acaricide to white-tailed deer. Although reductions in the abundance of all life-stages of Ixodes scapularis were the measured outcomes, this study focused on metrics associated with I. scapularis nymphal tick densities as this measure has consistently proven to directly correlate with human risk of acquiring Lyme disease. Since independent tick sampling schemes were undertaken at each of the five environmentally distinct study locations, a meta-analytic approach permitted estimation of a single true control-effect size for each treatment year of the NEATCP. The control-effect is expressed as the annual percent I. scapularis nymphal control most consistent with meta-analysis data for each treatment year. Our meta-analyses indicate that by the sixth treatment year, the NEATCP effectively reduced the relative density of I. scapularis nymphs by 71% on the 5.14 km2 treatment sites, corresponding to a 71% lower relative entomologic risk index for acquiring Lyme disease. PMID:19650737

  2. Grey literature in meta-analyses.

    Science.gov (United States)

    Conn, Vicki S; Valentine, Jeffrey C; Cooper, Harris M; Rantz, Marilyn J

    2003-01-01

    In meta-analysis, researchers combine the results of individual studies to arrive at cumulative conclusions. Meta-analysts sometimes include "grey literature" in their evidential base, which includes unpublished studies and studies published outside widely available journals. Because grey literature is a source of data that might not employ peer review, critics have questioned the validity of its data and the results of meta-analyses that include it. To examine evidence regarding whether grey literature should be included in meta-analyses and strategies to manage grey literature in quantitative synthesis. This article reviews evidence on whether the results of studies published in peer-reviewed journals are representative of results from broader samplings of research on a topic as a rationale for inclusion of grey literature. Strategies to enhance access to grey literature are addressed. The most consistent and robust difference between published and grey literature is that published research is more likely to contain results that are statistically significant. Effect size estimates of published research are about one-third larger than those of unpublished studies. Unfunded and small sample studies are less likely to be published. Yet, importantly, methodological rigor does not differ between published and grey literature. Meta-analyses that exclude grey literature likely (a) over-represent studies with statistically significant findings, (b) inflate effect size estimates, and (c) provide less precise effect size estimates than meta-analyses including grey literature. Meta-analyses should include grey literature to fully reflect the existing evidential base and should assess the impact of methodological variations through moderator analysis.

  3. Random error in cardiovascular meta-analyses

    DEFF Research Database (Denmark)

    Albalawi, Zaina; McAlister, Finlay A; Thorlund, Kristian

    2013-01-01

    BACKGROUND: Cochrane reviews are viewed as the gold standard in meta-analyses given their efforts to identify and limit systematic error which could cause spurious conclusions. The potential for random error to cause spurious conclusions in meta-analyses is less well appreciated. METHODS: We exam...

  4. Systematic review finds that study data not published in full text articles have unclear impact on meta-analyses results in medical research.

    Science.gov (United States)

    Schmucker, Christine M; Blümle, Anette; Schell, Lisa K; Schwarzer, Guido; Oeller, Patrick; Cabrera, Laura; von Elm, Erik; Briel, Matthias; Meerpohl, Joerg J

    2017-01-01

    A meta-analysis as part of a systematic review aims to provide a thorough, comprehensive and unbiased statistical summary of data from the literature. However, relevant study results could be missing from a meta-analysis because of selective publication and inadequate dissemination. If missing outcome data differ systematically from published ones, a meta-analysis will be biased with an inaccurate assessment of the intervention effect. As part of the EU-funded OPEN project (www.open-project.eu) we conducted a systematic review that assessed whether the inclusion of data that were not published at all and/or published only in the grey literature influences pooled effect estimates in meta-analyses and leads to different interpretation. Systematic review of published literature (methodological research projects). Four bibliographic databases were searched up to February 2016 without restriction of publication year or language. Methodological research projects were considered eligible for inclusion if they reviewed a cohort of meta-analyses which (i) compared pooled effect estimates of meta-analyses of health care interventions according to publication status of data or (ii) examined whether the inclusion of unpublished or grey literature data impacts the result of a meta-analysis. Seven methodological research projects including 187 meta-analyses comparing pooled treatment effect estimates according to different publication status were identified. Two research projects showed that published data showed larger pooled treatment effects in favour of the intervention than unpublished or grey literature data (Ratio of ORs 1.15, 95% CI 1.04-1.28 and 1.34, 95% CI 1.09-1.66). In the remaining research projects pooled effect estimates and/or overall findings were not significantly changed by the inclusion of unpublished and/or grey literature data. The precision of the pooled estimate was increased with narrower 95% confidence interval. Although we may anticipate that

  5. Publication bias in dermatology systematic reviews and meta-analyses.

    Science.gov (United States)

    Atakpo, Paul; Vassar, Matt

    2016-05-01

    Systematic reviews and meta-analyses in dermatology provide high-level evidence for clinicians and policy makers that influence clinical decision making and treatment guidelines. One methodological problem with systematic reviews is the under representation of unpublished studies. This problem is due in part to publication bias. Omission of statistically non-significant data from meta-analyses may result in overestimation of treatment effect sizes which may lead to clinical consequences. Our goal was to assess whether systematic reviewers in dermatology evaluate and report publication bias. Further, we wanted to conduct our own evaluation of publication bias on meta-analyses that failed to do so. Our study considered systematic reviews and meta-analyses from ten dermatology journals from 2006 to 2016. A PubMed search was conducted, and all full-text articles that met our inclusion criteria were retrieved and coded by the primary author. 293 articles were included in our analysis. Additionally, we formally evaluated publication bias in meta-analyses that failed to do so using trim and fill and cumulative meta-analysis by precision methods. Publication bias was mentioned in 107 articles (36.5%) and was formally evaluated in 64 articles (21.8%). Visual inspection of a funnel plot was the most common method of evaluating publication bias. Publication bias was present in 45 articles (15.3%), not present in 57 articles (19.5%) and not determined in 191 articles (65.2%). Using the trim and fill method, 7 meta-analyses (33.33%) showed evidence of publication bias. Although the trim and fill method only found evidence of publication bias in 7 meta-analyses, the cumulative meta-analysis by precision method found evidence of publication bias in 15 meta-analyses (71.4%). Many of the reviews in our study did not mention or evaluate publication bias. Further, of the 42 articles that stated following PRISMA reporting guidelines, 19 (45.2%) evaluated for publication bias. In

  6. Trial sequential analyses of meta-analyses of complications in laparoscopic vs. small-incision cholecystectomy: more randomized patients are needed

    DEFF Research Database (Denmark)

    Keus, Frederik; Wetterslev, Jørn; Gluud, Christian

    2010-01-01

    Conclusions based on meta-analyses of randomized trials carry a status of "truth." Methodological components may identify trials with systematic errors ("bias"). Trial sequential analysis (TSA) evaluates random errors in meta-analysis. We analyzed meta-analyses on laparoscopic vs. small-incision ......Conclusions based on meta-analyses of randomized trials carry a status of "truth." Methodological components may identify trials with systematic errors ("bias"). Trial sequential analysis (TSA) evaluates random errors in meta-analysis. We analyzed meta-analyses on laparoscopic vs. small...

  7. Methodological Quality Assessment of Meta-analyses in Endodontics.

    Science.gov (United States)

    Kattan, Sereen; Lee, Su-Min; Kohli, Meetu R; Setzer, Frank C; Karabucak, Bekir

    2018-01-01

    The objectives of this review were to assess the methodological quality of published meta-analyses related to endodontics using the assessment of multiple systematic reviews (AMSTAR) tool and to provide a follow-up to previously published reviews. Three electronic databases were searched for eligible studies according to the inclusion and exclusion criteria: Embase via Ovid, The Cochrane Library, and Scopus. The electronic search was amended by a hand search of 6 dental journals (International Endodontic Journal; Journal of Endodontics; Australian Endodontic Journal; Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology; Endodontics and Dental Traumatology; and Journal of Dental Research). The searches were conducted to include articles published after July 2009, and the deadline for inclusion of the meta-analyses was November 30, 2016. The AMSTAR assessment tool was used to evaluate the methodological quality of all included studies. A total of 36 reports of meta-analyses were included. The overall quality of the meta-analyses reports was found to be medium, with an estimated mean overall AMSTAR score of 7.25 (95% confidence interval, 6.59-7.90). The most poorly assessed areas were providing an a priori design, the assessment of the status of publication, and publication bias. In recent publications in the field of endodontics, the overall quality of the reported meta-analyses is medium according to AMSTAR. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. A case study of discordant overlapping meta-analyses: vitamin d supplements and fracture.

    Directory of Open Access Journals (Sweden)

    Mark J Bolland

    Full Text Available BACKGROUND: Overlapping meta-analyses on the same topic are now very common, and discordant results often occur. To explore why discordant results arise, we examined a common topic for overlapping meta-analyses- vitamin D supplements and fracture. METHODS AND FINDINGS: We identified 24 meta-analyses of vitamin D (with or without calcium and fracture in a PubMed search in October 2013, and analysed a sample of 7 meta-analyses in the highest ranking general medicine journals. We used the AMSTAR tool to assess the quality of the meta-analyses, and compared their methodologies, analytic techniques and results. Applying the AMSTAR tool suggested the meta-analyses were generally of high quality. Despite this, there were important differences in trial selection, data extraction, and analytical methods that were only apparent after detailed assessment. 25 trials were included in at least one meta-analysis. Four meta-analyses included all eligible trials according to the stated inclusion and exclusion criteria, but the other 3 meta-analyses "missed" between 3 and 8 trials, and 2 meta-analyses included apparently ineligible trials. The relative risks used for individual trials differed between meta-analyses for total fracture in 10 of 15 trials, and for hip fracture in 6 of 12 trials, because of different outcome definitions and analytic approaches. The majority of differences (11/16 led to more favourable estimates of vitamin D efficacy compared to estimates derived from unadjusted intention-to-treat analyses using all randomised participants. The conclusions of the meta-analyses were discordant, ranging from strong statements that vitamin D prevents fractures to equally strong statements that vitamin D without calcium does not prevent fractures. CONCLUSIONS: Substantial differences in trial selection, outcome definition and analytic methods between overlapping meta-analyses led to discordant estimates of the efficacy of vitamin D for fracture prevention

  9. Identifying null meta-analyses that are ripe for updating

    Directory of Open Access Journals (Sweden)

    Fang Manchun

    2003-07-01

    Full Text Available Abstract Background As an increasingly large number of meta-analyses are published, quantitative methods are needed to help clinicians and systematic review teams determine when meta-analyses are not up to date. Methods We propose new methods for determining when non-significant meta-analytic results might be overturned, based on a prediction of the number of participants required in new studies. To guide decision making, we introduce the "new participant ratio", the ratio of the actual number of participants in new studies to the predicted number required to obtain statistical significance. A simulation study was conducted to study the performance of our methods and a real meta-analysis provides further evidence. Results In our three simulation configurations, our diagnostic test for determining whether a meta-analysis is out of date had sensitivity of 55%, 62%, and 49% with corresponding specificity of 85%, 80%, and 90% respectively. Conclusions Simulations suggest that our methods are able to detect out-of-date meta-analyses. These quick and approximate methods show promise for use by systematic review teams to help decide whether to commit the considerable resources required to update a meta-analysis. Further investigation and evaluation of the methods is required before they can be recommended for general use.

  10. Meta-analyses on viral hepatitis

    DEFF Research Database (Denmark)

    Gluud, Lise L; Gluud, Christian

    2009-01-01

    This article summarizes the meta-analyses of interventions for viral hepatitis A, B, and C. Some of the interventions assessed are described in small trials with unclear bias control. Other interventions are supported by large, high-quality trials. Although attempts have been made to adjust...

  11. Systematic review and meta-analyses

    DEFF Research Database (Denmark)

    Dreier, Julie Werenberg; Andersen, Anne-Marie Nybo; Berg-Beckhoff, Gabriele

    2014-01-01

    1990 were excluded. RESULTS: The available literature supported an increased risk of adverse offspring health in association with fever during pregnancy. The strongest evidence was available for neural tube defects, congenital heart defects, and oral clefts, in which meta-analyses suggested between a 1...

  12. A systematic review of the quality and impact of anxiety disorder meta-analyses.

    Science.gov (United States)

    Ipser, Jonathan C; Stein, Dan J

    2009-08-01

    Meta-analyses are seen as representing the pinnacle of a hierarchy of evidence used to inform clinical practice. Therefore, the potential importance of differences in the rigor with which they are conducted and reported warrants consideration. In this review, we use standardized instruments to describe the scientific and reporting quality of meta-analyses of randomized controlled trials of the treatment of anxiety disorders. We also use traditional and novel metrics of article impact to assess the influence of meta-analyses across a range of research fields in the anxiety disorders. Overall, although the meta-analyses that we examined had some flaws, their quality of reporting was generally acceptable. Neither the scientific nor reporting quality of the meta-analyses was predicted by any of the impact metrics. The finding that treatment meta-analyses were cited less frequently than quantitative reviews of studies in current "hot spots" of research (ie, genetics, imaging) points to the multifactorial nature of citation patterns. A list of the meta-analyses included in this review is available on an evidence-based website of anxiety and trauma-related disorders.

  13. Less is less: a systematic review of graph use in meta-analyses.

    Science.gov (United States)

    Schild, Anne H E; Voracek, Martin

    2013-09-01

    Graphs are an essential part of scientific communication. Complex datasets, of which meta-analyses are textbook examples, benefit the most from visualization. Although a number of graph options for meta-analyses exist, the extent to which these are used was hitherto unclear. A systematic review on graph use in meta-analyses in three disciplines (medicine, psychology, and business) and nine journals was conducted. Interdisciplinary differences, which are mirrored in the respective journals, were revealed, that is, graph use correlates with external factors rather than methodological considerations. There was only limited variation in graph types (with forest plots as the most important representatives), and diagnostic plots were very rare. Although an increase in graph use over time could be observed, it is unlikely that this phenomenon is specific to meta-analyses. There is a gaping discrepancy between available graphic methods and their application in meta-analyses. This may be rooted in a number of factors, namely, (i) insufficient dissemination of new developments, (ii) unsatisfactory implementation in software packages, and (iii) minor attention on graphics in meta-analysis reporting guidelines. Using visualization methods to their full capacity is a further step in using meta-analysis to its full potential. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Effect of reporting bias on meta-analyses of drug trials

    DEFF Research Database (Denmark)

    Hart, Beth; Lundh, Andreas; Bero, Lisa

    2012-01-01

    To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials.......To investigate the effect of including unpublished trial outcome data obtained from the Food and Drug Administration (FDA) on the results of meta-analyses of drug trials....

  15. Twenty years of meta-analyses in orthopaedic surgery: has quality kept up with quantity?

    Science.gov (United States)

    Dijkman, Bernadette G; Abouali, Jihad A K; Kooistra, Bauke W; Conter, Henry J; Poolman, Rudolf W; Kulkarni, Abhaya V; Tornetta, Paul; Bhandari, Mohit

    2010-01-01

    As the number of studies in the literature is increasing, orthopaedic surgeons highly depend on meta-analyses as their primary source of scientific evidence. The objectives of this review were to assess the scientific quality and number of published meta-analyses on orthopaedics-related topics over time. We conducted, in duplicate and independently, a systematic review of published meta-analyses in orthopaedics in the years 2005 and 2008 and compared them with a previous systematic review of meta-analyses from 1969 to 1999. A search of electronic databases (MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews) was performed to identify meta-analyses published in 2005 and 2008. We searched bibliographies and contacted content experts to identify additional relevant studies. Two investigators independently assessed the quality of the studies, using the Oxman and Guyatt index, and abstracted relevant data. We included forty-five and forty-four meta-analyses from 2005 and 2008, respectively. While the number of meta-analyses increased fivefold from 1999 to 2008, the mean quality score did not change significantly over time (p = 0.067). In the later years, a significantly lower proportion of meta-analyses had methodological flaws (56% in 2005 and 68% in 2008) compared with meta-analyses published prior to 2000 (88%) (p = 0.006). In 2005 and 2008, respectively, 18% and 30% of the meta-analyses had major to extensive flaws in their methodology. Studies from 2008 with positive conclusions used and described appropriate criteria for the validity assessment less often than did those with negative results. The use of random-effects and fixed-effects models as pooling methods became more popular toward 2008. Although the methodological quality of orthopaedic meta-analyses has increased in the past twenty years, a substantial proportion continues to show major to extensive flaws. As the number of published meta-analyses is increasing, a routine checklist for

  16. Meta-Analyses of Human Cell-Based Cardiac Regeneration Therapies

    DEFF Research Database (Denmark)

    Gyöngyösi, Mariann; Wojakowski, Wojciech; Navarese, Eliano P

    2016-01-01

    In contrast to multiple publication-based meta-analyses involving clinical cardiac regeneration therapy in patients with recent myocardial infarction, a recently published meta-analysis based on individual patient data reported no effect of cell therapy on left ventricular function or clinical...

  17. A Microsoft-Excel-based tool for running and critically appraising network meta-analyses--an overview and application of NetMetaXL.

    Science.gov (United States)

    Brown, Stephen; Hutton, Brian; Clifford, Tammy; Coyle, Doug; Grima, Daniel; Wells, George; Cameron, Chris

    2014-09-29

    The use of network meta-analysis has increased dramatically in recent years. WinBUGS, a freely available Bayesian software package, has been the most widely used software package to conduct network meta-analyses. However, the learning curve for WinBUGS can be daunting, especially for new users. Furthermore, critical appraisal of network meta-analyses conducted in WinBUGS can be challenging given its limited data manipulation capabilities and the fact that generation of graphical output from network meta-analyses often relies on different software packages than the analyses themselves. We developed a freely available Microsoft-Excel-based tool called NetMetaXL, programmed in Visual Basic for Applications, which provides an interface for conducting a Bayesian network meta-analysis using WinBUGS from within Microsoft Excel. . This tool allows the user to easily prepare and enter data, set model assumptions, and run the network meta-analysis, with results being automatically displayed in an Excel spreadsheet. It also contains macros that use NetMetaXL's interface to generate evidence network diagrams, forest plots, league tables of pairwise comparisons, probability plots (rankograms), and inconsistency plots within Microsoft Excel. All figures generated are publication quality, thereby increasing the efficiency of knowledge transfer and manuscript preparation. We demonstrate the application of NetMetaXL using data from a network meta-analysis published previously which compares combined resynchronization and implantable defibrillator therapy in left ventricular dysfunction. We replicate results from the previous publication while demonstrating result summaries generated by the software. Use of the freely available NetMetaXL successfully demonstrated its ability to make running network meta-analyses more accessible to novice WinBUGS users by allowing analyses to be conducted entirely within Microsoft Excel. NetMetaXL also allows for more efficient and transparent

  18. Meta-analyses triggered by previous (false-)significant findings : Problems and solutions

    NARCIS (Netherlands)

    Schuit, Ewoud; Roes, Kit C B; Mol, Ben W J; Kwee, Anneke; Moons, Karel G M; Groenwold, Rolf H H

    2015-01-01

    BACKGROUND: Meta-analyses are typically triggered by a (potentially false-significant) finding in one of the preceding primary studies. We studied consequences of meta-analysis investigating effects when primary studies that triggered such meta-analysis are also included. METHODS: We analytically

  19. Apparently conclusive meta-analyses may be inconclusive--Trial sequential analysis adjustment of random error risk due to repetitive testing of accumulating data in apparently conclusive neonatal meta-analyses

    DEFF Research Database (Denmark)

    Brok, Jesper; Thorlund, Kristian; Wetterslev, Jørn

    2008-01-01

    BACKGROUND: Random error may cause misleading evidence in meta-analyses. The required number of participants in a meta-analysis (i.e. information size) should be at least as large as an adequately powered single trial. Trial sequential analysis (TSA) may reduce risk of random errors due to repeti......BACKGROUND: Random error may cause misleading evidence in meta-analyses. The required number of participants in a meta-analysis (i.e. information size) should be at least as large as an adequately powered single trial. Trial sequential analysis (TSA) may reduce risk of random errors due...

  20. Meta-analyses of HFE variants in coronary heart disease.

    Science.gov (United States)

    Lian, Jiangfang; Xu, Limin; Huang, Yi; Le, Yanping; Jiang, Danjie; Yang, Xi; Xu, Weifeng; Huang, Xiaoyan; Dong, Changzheng; Ye, Meng; Zhou, Jianqing; Duan, Shiwei

    2013-09-15

    HFE gene variants can cause hereditary hemochromatosis (HH) that often comes along with an increased risk of coronary heart disease (CHD). The goal of our study is to assess the contribution of four HFE gene variants to the risk of CHD. We conducted four meta-analyses of the studies examining the association between four HFE gene variants and the risk of CHD. A systematic search was conducted using MEDLINE, EMBASE, Web of Science and China National Knowledge Infrastructure (CNKI), Wanfang Chinese Periodical. Meta-analyses showed that HFE rs1799945-G allele was associated with a 6% increased risk of CHD (P=0.02, odds ratio (OR)=1.06, 95% confidence interval (CI)=1.01-1.11). However, no association between the other three HFE gene variants (rs1800562, rs1800730, and rs9366637) and CHD risk was observed by the meta-analyses (all P values>0.05). In addition, the results of our case-control study indicated that rs1800562 and rs1800730 were monomorphic, and that rs1799945 and rs9366637 were not associated with CHD in Han Chinese. Our meta-analysis suggested that a significant association existed between rs1799945 mutation and CHD, although this mutation was rare in Han Chinese. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Investigation of publication bias in meta-analyses of diagnostic test accuracy: a meta-epidemiological study

    NARCIS (Netherlands)

    van Enst, W. Annefloor; Ochodo, Eleanor; Scholten, Rob J. P. M.; Hooft, Lotty; Leeflang, Mariska M.

    2014-01-01

    The validity of a meta-analysis can be understood better in light of the possible impact of publication bias. The majority of the methods to investigate publication bias in terms of small study-effects are developed for meta-analyses of intervention studies, leaving authors of diagnostic test

  2. Early Versus Delayed Motion After Rotator Cuff Repair: A Systematic Review of Overlapping Meta-analyses.

    Science.gov (United States)

    Houck, Darby A; Kraeutler, Matthew J; Schuette, Hayden B; McCarty, Eric C; Bravman, Jonathan T

    2017-10-01

    Previous meta-analyses have been conducted to compare outcomes of early versus delayed motion after rotator cuff repair. To conduct a systematic review of overlapping meta-analyses comparing early versus delayed motion rehabilitation protocols after rotator cuff repair to determine which meta-analyses provide the best available evidence. Systematic review. A systematic review was performed by searching PubMed and Cochrane Library databases. Search terms included "rotator cuff repair," "early passive motion," "immobilization," "rehabilitation protocol," and "meta-analysis." Results were reviewed to determine study eligibility. Patient outcomes and structural healing were extracted from these meta-analyses. Meta-analysis quality was assessed using the Oxman-Guyatt and Quality of Reporting of Meta-analyses (QUOROM) systems. The Jadad decision algorithm was then used to determine which meta-analyses provided the best level of evidence. Seven meta-analyses containing a total of 5896 patients met the eligibility criteria (1 Level I evidence, 4 Level II evidence, 2 Level III evidence). None of these meta-analyses found immobilization to be superior to early motion; however, most studies suggested that early motion would increase range of motion (ROM), thereby reducing time of recovery. Three of these studies suggested that tear size contributed to the choice of rehabilitation to ensure proper healing of the shoulder. A study by Chan et al in 2014 received the highest QUOROM and Oxman-Guyatt scores, and therefore this meta-analysis appeared to have the highest level of evidence. Additionally, a study by Riboh and Garrigues in 2014 was selected as the highest quality study in this systematic review according to the Jadad decision algorithm. The current, best available evidence suggests that early motion improves ROM after rotator cuff repair but increases the risk of rotator cuff retear. Lower quality meta-analyses indicate that tear size may provide a better strategy in

  3. Homeopathy: meta-analyses of pooled clinical data.

    Science.gov (United States)

    Hahn, Robert G

    2013-01-01

    In the first decade of the evidence-based era, which began in the mid-1990s, meta-analyses were used to scrutinize homeopathy for evidence of beneficial effects in medical conditions. In this review, meta-analyses including pooled data from placebo-controlled clinical trials of homeopathy and the aftermath in the form of debate articles were analyzed. In 1997 Klaus Linde and co-workers identified 89 clinical trials that showed an overall odds ratio of 2.45 in favor of homeopathy over placebo. There was a trend toward smaller benefit from studies of the highest quality, but the 10 trials with the highest Jadad score still showed homeopathy had a statistically significant effect. These results challenged academics to perform alternative analyses that, to demonstrate the lack of effect, relied on extensive exclusion of studies, often to the degree that conclusions were based on only 5-10% of the material, or on virtual data. The ultimate argument against homeopathy is the 'funnel plot' published by Aijing Shang's research group in 2005. However, the funnel plot is flawed when applied to a mixture of diseases, because studies with expected strong treatments effects are, for ethical reasons, powered lower than studies with expected weak or unclear treatment effects. To conclude that homeopathy lacks clinical effect, more than 90% of the available clinical trials had to be disregarded. Alternatively, flawed statistical methods had to be applied. Future meta-analyses should focus on the use of homeopathy in specific diseases or groups of diseases instead of pooling data from all clinical trials. © 2013 S. Karger GmbH, Freiburg.

  4. A Meta-Meta-Analysis: Empirical Review of Statistical Power, Type I Error Rates, Effect Sizes, and Model Selection of Meta-Analyses Published in Psychology

    Science.gov (United States)

    Cafri, Guy; Kromrey, Jeffrey D.; Brannick, Michael T.

    2010-01-01

    This article uses meta-analyses published in "Psychological Bulletin" from 1995 to 2005 to describe meta-analyses in psychology, including examination of statistical power, Type I errors resulting from multiple comparisons, and model choice. Retrospective power estimates indicated that univariate categorical and continuous moderators, individual…

  5. Conducting Meta-Analyses Based on p Values

    Science.gov (United States)

    van Aert, Robbie C. M.; Wicherts, Jelte M.; van Assen, Marcel A. L. M.

    2016-01-01

    Because of overwhelming evidence of publication bias in psychology, techniques to correct meta-analytic estimates for such bias are greatly needed. The methodology on which the p-uniform and p-curve methods are based has great promise for providing accurate meta-analytic estimates in the presence of publication bias. However, in this article, we show that in some situations, p-curve behaves erratically, whereas p-uniform may yield implausible estimates of negative effect size. Moreover, we show that (and explain why) p-curve and p-uniform result in overestimation of effect size under moderate-to-large heterogeneity and may yield unpredictable bias when researchers employ p-hacking. We offer hands-on recommendations on applying and interpreting results of meta-analyses in general and p-uniform and p-curve in particular. Both methods as well as traditional methods are applied to a meta-analysis on the effect of weight on judgments of importance. We offer guidance for applying p-uniform or p-curve using R and a user-friendly web application for applying p-uniform. PMID:27694466

  6. Can trial sequential monitoring boundaries reduce spurious inferences from meta-analyses?

    DEFF Research Database (Denmark)

    Thorlund, Kristian; Devereaux, P J; Wetterslev, Jørn

    2008-01-01

    BACKGROUND: Results from apparently conclusive meta-analyses may be false. A limited number of events from a few small trials and the associated random error may be under-recognized sources of spurious findings. The information size (IS, i.e. number of participants) required for a reliable......-analyses after each included trial and evaluated their results using a conventional statistical criterion (alpha = 0.05) and two-sided Lan-DeMets monitoring boundaries. We examined the proportion of false positive results and important inaccuracies in estimates of treatment effects that resulted from the two...... approaches. RESULTS: Using the random-effects model and final data, 12 of the meta-analyses yielded P > alpha = 0.05, and 21 yielded P alpha = 0.05. The monitoring boundaries eliminated all false positives. Important inaccuracies in estimates were observed in 6 out of 21 meta-analyses using the conventional...

  7. Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data: the PRISMA-IPD Statement.

    Science.gov (United States)

    Stewart, Lesley A; Clarke, Mike; Rovers, Maroeska; Riley, Richard D; Simmonds, Mark; Stewart, Gavin; Tierney, Jayne F

    2015-04-28

    Systematic reviews and meta-analyses of individual participant data (IPD) aim to collect, check, and reanalyze individual-level data from all studies addressing a particular research question and are therefore considered a gold standard approach to evidence synthesis. They are likely to be used with increasing frequency as current initiatives to share clinical trial data gain momentum and may be particularly important in reviewing controversial therapeutic areas. To develop PRISMA-IPD as a stand-alone extension to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement, tailored to the specific requirements of reporting systematic reviews and meta-analyses of IPD. Although developed primarily for reviews of randomized trials, many items will apply in other contexts, including reviews of diagnosis and prognosis. Development of PRISMA-IPD followed the EQUATOR Network framework guidance and used the existing standard PRISMA Statement as a starting point to draft additional relevant material. A web-based survey informed discussion at an international workshop that included researchers, clinicians, methodologists experienced in conducting systematic reviews and meta-analyses of IPD, and journal editors. The statement was drafted and iterative refinements were made by the project, advisory, and development groups. The PRISMA-IPD Development Group reached agreement on the PRISMA-IPD checklist and flow diagram by consensus. Compared with standard PRISMA, the PRISMA-IPD checklist includes 3 new items that address (1) methods of checking the integrity of the IPD (such as pattern of randomization, data consistency, baseline imbalance, and missing data), (2) reporting any important issues that emerge, and (3) exploring variation (such as whether certain types of individual benefit more from the intervention than others). A further additional item was created by reorganization of standard PRISMA items relating to interpreting results. Wording

  8. Night shift work and breast cancer risk: what do the meta-analyses tell us?

    Science.gov (United States)

    Pahwa, Manisha; Labrèche, France; Demers, Paul A

    2018-05-22

    Objectives This paper aims to compare results, assess the quality, and discuss the implications of recently published meta-analyses of night shift work and breast cancer risk. Methods A comprehensive search was conducted for meta-analyses published from 2007-2017 that included at least one pooled effect size (ES) for breast cancer associated with any night shift work exposure metric and were accompanied by a systematic literature review. Pooled ES from each meta-analysis were ascertained with a focus on ever/never exposure associations. Assessments of heterogeneity and publication bias were also extracted. The AMSTAR 2 checklist was used to evaluate quality. Results Seven meta-analyses, published from 2013-2016, collectively included 30 cohort and case-control studies spanning 1996-2016. Five meta-analyses reported pooled ES for ever/never night shift work exposure; these ranged from 0.99 [95% confidence interval (CI) 0.95-1.03, N=10 cohort studies) to 1.40 (95% CI 1.13-1.73, N=9 high quality studies). Estimates for duration, frequency, and cumulative night shift work exposure were scant and mostly not statistically significant. Meta-analyses of cohort, Asian, and more fully-adjusted studies generally resulted in lower pooled ES than case-control, European, American, or minimally-adjusted studies. Most reported statistically significant between-study heterogeneity. Publication bias was not evident in any of the meta-analyses. Only one meta-analysis was strong in critical quality domains. Conclusions Fairly consistent elevated pooled ES were found for ever/never night shift work and breast cancer risk, but results for other shift work exposure metrics were inconclusive. Future evaluations of shift work should incorporate high quality meta-analyses that better appraise individual study quality.

  9. Meta-analyses of the 5-HTTLPR polymorphisms and post-traumatic stress disorder.

    Directory of Open Access Journals (Sweden)

    Fernando Navarro-Mateu

    Full Text Available OBJECTIVE: To conduct a meta-analysis of all published genetic association studies of 5-HTTLPR polymorphisms performed in PTSD cases. METHODS DATA SOURCES: Potential studies were identified through PubMed/MEDLINE, EMBASE, Web of Science databases (Web of Knowledge, WoK, PsychINFO, PsychArticles and HuGeNet (Human Genome Epidemiology Network up until December 2011. STUDY SELECTION: Published observational studies reporting genotype or allele frequencies of this genetic factor in PTSD cases and in non-PTSD controls were all considered eligible for inclusion in this systematic review. DATA EXTRACTION: Two reviewers selected studies for possible inclusion and extracted data independently following a standardized protocol. STATISTICAL ANALYSIS: A biallelic and a triallelic meta-analysis, including the total S and S' frequencies, the dominant (S+/LL and S'+/L'L' and the recessive model (SS/L+ and S'S'/L'+, was performed with a random-effect model to calculate the pooled OR and its corresponding 95% CI. Forest plots and Cochran's Q-Statistic and I(2 index were calculated to check for heterogeneity. Subgroup analyses and meta-regression were carried out to analyze potential moderators. Publication bias and quality of reporting were also analyzed. RESULTS: 13 studies met our inclusion criteria, providing a total sample of 1874 patients with PTSD and 7785 controls in the biallelic meta-analyses and 627 and 3524, respectively, in the triallelic. None of the meta-analyses showed evidence of an association between 5-HTTLPR and PTSD but several characteristics (exposure to the same principal stressor for PTSD cases and controls, adjustment for potential confounding variables, blind assessment, study design, type of PTSD, ethnic distribution and Total Quality Score influenced the results in subgroup analyses and meta-regression. There was no evidence of potential publication bias. CONCLUSIONS: Current evidence does not support a direct effect of 5-HTTLPR

  10. Meta-analyses of the 5-HTTLPR polymorphisms and post-traumatic stress disorder.

    Science.gov (United States)

    Navarro-Mateu, Fernando; Escámez, Teresa; Koenen, Karestan C; Alonso, Jordi; Sánchez-Meca, Julio

    2013-01-01

    To conduct a meta-analysis of all published genetic association studies of 5-HTTLPR polymorphisms performed in PTSD cases. Potential studies were identified through PubMed/MEDLINE, EMBASE, Web of Science databases (Web of Knowledge, WoK), PsychINFO, PsychArticles and HuGeNet (Human Genome Epidemiology Network) up until December 2011. Published observational studies reporting genotype or allele frequencies of this genetic factor in PTSD cases and in non-PTSD controls were all considered eligible for inclusion in this systematic review. Two reviewers selected studies for possible inclusion and extracted data independently following a standardized protocol. A biallelic and a triallelic meta-analysis, including the total S and S' frequencies, the dominant (S+/LL and S'+/L'L') and the recessive model (SS/L+ and S'S'/L'+), was performed with a random-effect model to calculate the pooled OR and its corresponding 95% CI. Forest plots and Cochran's Q-Statistic and I(2) index were calculated to check for heterogeneity. Subgroup analyses and meta-regression were carried out to analyze potential moderators. Publication bias and quality of reporting were also analyzed. 13 studies met our inclusion criteria, providing a total sample of 1874 patients with PTSD and 7785 controls in the biallelic meta-analyses and 627 and 3524, respectively, in the triallelic. None of the meta-analyses showed evidence of an association between 5-HTTLPR and PTSD but several characteristics (exposure to the same principal stressor for PTSD cases and controls, adjustment for potential confounding variables, blind assessment, study design, type of PTSD, ethnic distribution and Total Quality Score) influenced the results in subgroup analyses and meta-regression. There was no evidence of potential publication bias. Current evidence does not support a direct effect of 5-HTTLPR polymorphisms on PTSD. Further analyses of gene-environment interactions, epigenetic modulation and new studies with large samples

  11. Network meta-analyses performed by contracting companies and commissioned by industry

    NARCIS (Netherlands)

    Schuit, Ewoud; Ioannidis, John P A

    2016-01-01

    Background: Industry commissions contracting companies to perform network meta-analysis for health technology assessment (HTA) and reimbursement submissions. Our objective was to estimate the number of network meta-analyses performed by consulting companies contracted by industry, to assess whether

  12. Altered Brain Activity in Unipolar Depression Revisited: Meta-analyses of Neuroimaging Studies.

    Science.gov (United States)

    Müller, Veronika I; Cieslik, Edna C; Serbanescu, Ilinca; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

    2017-01-01

    During the past 20 years, numerous neuroimaging experiments have investigated aberrant brain activation during cognitive and emotional processing in patients with unipolar depression (UD). The results of those investigations, however, vary considerably; moreover, previous meta-analyses also yielded inconsistent findings. To readdress aberrant brain activation in UD as evidenced by neuroimaging experiments on cognitive and/or emotional processing. Neuroimaging experiments published from January 1, 1997, to October 1, 2015, were identified by a literature search of PubMed, Web of Science, and Google Scholar using different combinations of the terms fMRI (functional magnetic resonance imaging), PET (positron emission tomography), neural, major depression, depression, major depressive disorder, unipolar depression, dysthymia, emotion, emotional, affective, cognitive, task, memory, working memory, inhibition, control, n-back, and Stroop. Neuroimaging experiments (using fMRI or PET) reporting whole-brain results of group comparisons between adults with UD and healthy control individuals as coordinates in a standard anatomic reference space and using an emotional or/and cognitive challenging task were selected. Coordinates reported to show significant activation differences between UD and healthy controls during emotional or cognitive processing were extracted. By using the revised activation likelihood estimation algorithm, different meta-analyses were calculated. Meta-analyses tested for brain regions consistently found to show aberrant brain activation in UD compared with controls. Analyses were calculated across all emotional processing experiments, all cognitive processing experiments, positive emotion processing, negative emotion processing, experiments using emotional face stimuli, experiments with a sex discrimination task, and memory processing. All meta-analyses were calculated across experiments independent of reporting an increase or decrease of activity in

  13. Trial sequential analysis reveals insufficient information size and potentially false positive results in many meta-analyses

    DEFF Research Database (Denmark)

    Brok, J.; Thorlund, K.; Gluud, C.

    2008-01-01

    in 80% (insufficient information size). TSA(15%) and TSA(LBHIS) found that 95% and 91% had absence of evidence. The remaining nonsignificant meta-analyses had evidence of lack of effect. CONCLUSION: TSA reveals insufficient information size and potentially false positive results in many meta......OBJECTIVES: To evaluate meta-analyses with trial sequential analysis (TSA). TSA adjusts for random error risk and provides the required number of participants (information size) in a meta-analysis. Meta-analyses not reaching information size are analyzed with trial sequential monitoring boundaries...... analogous to interim monitoring boundaries in a single trial. STUDY DESIGN AND SETTING: We applied TSA on meta-analyses performed in Cochrane Neonatal reviews. We calculated information sizes and monitoring boundaries with three different anticipated intervention effects of 30% relative risk reduction (TSA...

  14. Does the inclusion of grey literature influence estimates of intervention effectiveness reported in meta-analyses?

    Science.gov (United States)

    McAuley, L; Pham, B; Tugwell, P; Moher, D

    2000-10-07

    The inclusion of only a subset of all available evidence in a meta-analysis may introduce biases and threaten its validity; this is particularly likely if the subset of included studies differ from those not included, which may be the case for published and grey literature (unpublished studies, with limited distribution). We set out to examine whether exclusion of grey literature, compared with its inclusion in meta-analysis, provides different estimates of the effectiveness of interventions assessed in randomised trials. From a random sample of 135 meta-analyses, we identified and retrieved 33 publications that included both grey and published primary studies. The 33 publications contributed 41 separate meta-analyses from several disease areas. General characteristics of the meta-analyses and associated studies and outcome data at the trial level were collected. We explored the effects of the inclusion of grey literature on the quantitative results using logistic-regression analyses. 33% of the meta-analyses were found to include some form of grey literature. The grey literature, when included, accounts for between 4.5% and 75% of the studies in a meta-analysis. On average, published work, compared with grey literature, yielded significantly larger estimates of the intervention effect by 15% (ratio of odds ratios=1.15 [95% CI 1.04-1.28]). Excluding abstracts from the analysis further compounded the exaggeration (1.33 [1.10-1.60]). The exclusion of grey literature from meta-analyses can lead to exaggerated estimates of intervention effectiveness. In general, meta-analysts should attempt to identify, retrieve, and include all reports, grey and published, that meet predefined inclusion criteria.

  15. A simple technique investigating baseline heterogeneity helped to eliminate potential bias in meta-analyses.

    Science.gov (United States)

    Hicks, Amy; Fairhurst, Caroline; Torgerson, David J

    2018-03-01

    To perform a worked example of an approach that can be used to identify and remove potentially biased trials from meta-analyses via the analysis of baseline variables. True randomisation produces treatment groups that differ only by chance; therefore, a meta-analysis of a baseline measurement should produce no overall difference and zero heterogeneity. A meta-analysis from the British Medical Journal, known to contain significant heterogeneity and imbalance in baseline age, was chosen. Meta-analyses of baseline variables were performed and trials systematically removed, starting with those with the largest t-statistic, until the I 2 measure of heterogeneity became 0%, then the outcome meta-analysis repeated with only the remaining trials as a sensitivity check. We argue that heterogeneity in a meta-analysis of baseline variables should not exist, and therefore removing trials which contribute to heterogeneity from a meta-analysis will produce a more valid result. In our example none of the overall outcomes changed when studies contributing to heterogeneity were removed. We recommend routine use of this technique, using age and a second baseline variable predictive of outcome for the particular study chosen, to help eliminate potential bias in meta-analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Comprehensive research synopsis and systematic meta-analyses in Parkinson's disease genetics: The PDGene database.

    Directory of Open Access Journals (Sweden)

    Christina M Lill

    Full Text Available More than 800 published genetic association studies have implicated dozens of potential risk loci in Parkinson's disease (PD. To facilitate the interpretation of these findings, we have created a dedicated online resource, PDGene, that comprehensively collects and meta-analyzes all published studies in the field. A systematic literature screen of -27,000 articles yielded 828 eligible articles from which relevant data were extracted. In addition, individual-level data from three publicly available genome-wide association studies (GWAS were obtained and subjected to genotype imputation and analysis. Overall, we performed meta-analyses on more than seven million polymorphisms originating either from GWAS datasets and/or from smaller scale PD association studies. Meta-analyses on 147 SNPs were supplemented by unpublished GWAS data from up to 16,452 PD cases and 48,810 controls. Eleven loci showed genome-wide significant (P < 5 × 10(-8 association with disease risk: BST1, CCDC62/HIP1R, DGKQ/GAK, GBA, LRRK2, MAPT, MCCC1/LAMP3, PARK16, SNCA, STK39, and SYT11/RAB25. In addition, we identified novel evidence for genome-wide significant association with a polymorphism in ITGA8 (rs7077361, OR 0.88, P  =  1.3 × 10(-8. All meta-analysis results are freely available on a dedicated online database (www.pdgene.org, which is cross-linked with a customized track on the UCSC Genome Browser. Our study provides an exhaustive and up-to-date summary of the status of PD genetics research that can be readily scaled to include the results of future large-scale genetics projects, including next-generation sequencing studies.

  17. Systematic literature reviews and meta-analyses: part 6 of a series on evaluation of scientific publications.

    Science.gov (United States)

    Ressing, Meike; Blettner, Maria; Klug, Stefanie J

    2009-07-01

    Because of the rising number of scientific publications, it is important to have a means of jointly summarizing and assessing different studies on a single topic. Systematic literature reviews, meta-analyses of published data, and meta-analyses of individual data (pooled reanalyses) are now being published with increasing frequency. We here describe the essential features of these methods and discuss their strengths and weaknesses. This article is based on a selective literature search. The different types of review and meta-analysis are described, the methods used in each are outlined so that they can be evaluated, and a checklist is given for the assessment of reviews and meta-analyses of scientific articles. Systematic literature reviews provide an overview of the state of research on a given topic and enable an assessment of the quality of individual studies. They also allow the results of different studies to be evaluated together when these are inconsistent. Meta-analyses additionally allow calculation of pooled estimates of an effect. The different types of review and meta-analysis are discussed with examples from the literature on one particular topic. Systematic literature reviews and meta-analyses enable the research findings and treatment effects obtained in different individual studies to be summed up and evaluated.

  18. Meta-Analyses of Predictors of Hope in Adolescents.

    Science.gov (United States)

    Yarcheski, Adela; Mahon, Noreen E

    2016-03-01

    The purposes of this study were to identify predictors of hope in the literature reviewed, to use meta-analysis to determine the mean effect size (ES) across studies between each predictor and hope, and to examine four moderators on each predictor-hope relationship. Using preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines for the literature reviewed, 77 published studies or doctoral dissertations completed between 1990 and 2012 met the inclusion criteria. Eleven predictors of hope were identified and each predictor in relation to hope was subjected to meta-analysis. Five predictors (positive affect, life satisfaction, optimism, self-esteem, and social support) of hope had large mean ESs, 1 predictor (depression) had a medium ES, 4 predictors (negative affect, stress, academic achievement, and violence) had small ESs, and 1 predictor (gender) had a trivial ES. Findings are interpreted for the 11 predictors in relation to hope. Limitations and conclusions are addressed; future studies are recommended. © The Author(s) 2014.

  19. Exercise improves depressive symptoms in older adults: An umbrella review of systematic reviews and meta-analyses.

    Science.gov (United States)

    Catalan-Matamoros, Daniel; Gomez-Conesa, Antonia; Stubbs, Brendon; Vancampfort, Davy

    2016-10-30

    Late-life depression is a growing public health concern. Exercise may be of added value but the literature remains equivocal. We conducted a systematic overview of meta-analyses and an exploratory pooled analysis of previous meta-analyses to determine the effect of exercise on depression in older adults. Two independent researchers searched Pubmed, CINAHL, Cochrane Plus, PsycArticles, and PsycInfo for meta-analyses on exercise in late-life depression. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR) Instrument. We pooled effect sizes from previous meta-analyses of randomized controlled trials to determine the effect of exercise on depression in older adults. The systematic review yielded 3 meta-analyses. In total, 16 unique cohorts of 1487 participants were included. The quality of the three included meta-analyses was considered as "moderate" according to AMSTAR scores. No serious adverse events were reported. Compared to controls (n=583), those exercising (n=541) significantly reduced depressive symptoms. Our umbrella review indicates that exercise is safe and efficacious in reducing depressive symptoms in older people. Since exercise has many other known health benefits, it should be considered as a core intervention in the multidisciplinary treatment of older adults experiencing depression. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Ain't necessarily so: review and critique of recent meta-analyses of behavioral medicine interventions in health psychology.

    Science.gov (United States)

    Coyne, James C; Thombs, Brett D; Hagedoorn, Mariet

    2010-03-01

    We examined four meta-analyses of behavioral interventions for adults (Dixon, Keefe, Scipio, Perri, & Abernethy, 2007; Hoffman, Papas, Chatkoff, & Kerns, 2007; Irwin, Cole, & Nicassio, 2006; and Jacobsen, Donovan, Vadaparampil, & Small, 2007) that have appeared in the Evidence Based Treatment Reviews section of Health Psychology. Narrative review. We applied the following criteria to each meta-analysis: (1) whether each meta-analysis was described accurately, adequately, and transparently in the article; (2) whether there was an adequate attempt to deal with methodological quality of the original trials; (3) the extent to which the meta-analysis depended on small, underpowered studies; and (4) the extent to which the meta-analysis provided valid and useful evidence-based recommendations. Across the four meta-analyses, we identified substantial problems with the transparency and completeness with which these meta-analyses were reported, as well as a dependence on small, underpowered trials of generally poor quality. Results of our exercise raise questions about the clinical validity and utility of the conclusions of these meta-analyses. Results should serve as a wake up call to prospective authors, reviewers, and end-users of meta-analyses now appearing in the literature. Copyright 2010 APA, all rights reserved.

  1. Stuttering, induced fluency, and natural fluency: a hierarchical series of activation likelihood estimation meta-analyses.

    Science.gov (United States)

    Budde, Kristin S; Barron, Daniel S; Fox, Peter T

    2014-12-01

    Developmental stuttering is a speech disorder most likely due to a heritable form of developmental dysmyelination impairing the function of the speech-motor system. Speech-induced brain-activation patterns in persons who stutter (PWS) are anomalous in various ways; the consistency of these aberrant patterns is a matter of ongoing debate. Here, we present a hierarchical series of coordinate-based meta-analyses addressing this issue. Two tiers of meta-analyses were performed on a 17-paper dataset (202 PWS; 167 fluent controls). Four large-scale (top-tier) meta-analyses were performed, two for each subject group (PWS and controls). These analyses robustly confirmed the regional effects previously postulated as "neural signatures of stuttering" (Brown, Ingham, Ingham, Laird, & Fox, 2005) and extended this designation to additional regions. Two smaller-scale (lower-tier) meta-analyses refined the interpretation of the large-scale analyses: (1) a between-group contrast targeting differences between PWS and controls (stuttering trait); and (2) a within-group contrast (PWS only) of stuttering with induced fluency (stuttering state). Copyright © 2014 Elsevier Inc. All rights reserved.

  2. False-positive findings in Cochrane meta-analyses with and without application of trial sequential analysis

    DEFF Research Database (Denmark)

    Imberger, Georgina; Thorlund, Kristian; Gluud, Christian

    2016-01-01

    outcome, a negative result and sufficient power. We defined a negative result as one where the 95% CI for the effect included 1.00, a positive result as one where the 95% CI did not include 1.00, and sufficient power as the required information size for 80% power, 5% type 1 error, relative risk reduction...... of 10% or number needed to treat of 100, and control event proportion and heterogeneity taken from the included studies. We re-conducted the meta-analyses, using conventional cumulative techniques, to measure how many false positives would have occurred if these meta-analyses had been updated after each...... new trial. For each false positive, we performed TSA, using three different approaches. RESULTS: We screened 4736 systematic reviews to find 100 meta-analyses that fulfilled our inclusion criteria. Using conventional cumulative meta-analysis, false positives were present in seven of the meta...

  3. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior.

    Science.gov (United States)

    Hagger, Martin S; Chan, Derwin K C; Protogerou, Cleo; Chatzisarantis, Nikos L D

    2016-08-01

    Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs from social cognitive theories is important to test nomological validity, account for mediation effects, and evaluate unique effects of theory constructs independent of past behavior. We illustrate our points by conducting new analyses of two meta-analyses of a popular theory applied to health behaviors, the theory of planned behavior. We conducted meta-analytic path analyses of the theory in two behavioral contexts (alcohol and dietary behaviors) using data from the primary studies included in the original meta-analyses augmented to include intercorrelations among constructs and relations with past behavior missing from the original analysis. Findings supported the nomological validity of the theory and its hypotheses for both behaviors, confirmed important model processes through mediation analysis, demonstrated the attenuating effect of past behavior on theory relations, and provided estimates of the unique effects of theory constructs independent of past behavior. Our analysis illustrates the importance of conducting a simultaneous test of theory-stipulated effects in meta-analyses of social cognitive theories applied to health behavior. We recommend researchers adopt this analytic procedure when synthesizing evidence across primary tests of social cognitive theories in health. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Conducting meta-analyses of HIV prevention literatures from a theory-testing perspective.

    Science.gov (United States)

    Marsh, K L; Johnson, B T; Carey, M P

    2001-09-01

    Using illustrations from HIV prevention research, the current article advocates approaching meta-analysis as a theory-testing scientific method rather than as merely a set of rules for quantitative analysis. Like other scientific methods, meta-analysis has central concerns with internal, external, and construct validity. The focus of a meta-analysis should only rarely be merely describing the effects of health promotion, but rather should be on understanding and explaining phenomena and the processes underlying them. The methodological decisions meta-analysts make in conducting reviews should be guided by a consideration of the underlying goals of the review (e.g., simply effect size estimation or, preferably theory testing). From the advocated perspective that a health behavior meta-analyst should test theory, the authors present a number of issues to be considered during the conduct of meta-analyses.

  5. Meta-analyses of workplace physical activity and dietary behaviour interventions on weight outcomes

    NARCIS (Netherlands)

    Verweij, L.M.; Coffeng, J.; Mechelen, W. van; Proper, K.I.

    2011-01-01

    This meta-analytic review critically examines the effectiveness of workplace interventions targeting physical activity, dietary behaviour or both on weight outcomes. Data could be extracted from 22 studies published between 1980 and November 2009 for meta-analyses. The GRADE approach was used to

  6. Reporting the results of meta-analyses: a plea for incorporating clinical relevance referring to an example.

    Science.gov (United States)

    Bartels, Ronald H M A; Donk, Roland D; Verhagen, Wim I M; Hosman, Allard J F; Verbeek, André L M

    2017-11-01

    The results of meta-analyses are frequently reported, but understanding and interpreting them is difficult for both clinicians and patients. Statistical significances are presented without referring to values that imply clinical relevance. This study aimed to use the minimal clinically important difference (MCID) to rate the clinical relevance of a meta-analysis. This study is a review of the literature. This study is a review of meta-analyses relating to a specific topic, clinical results of cervical arthroplasty. The outcome measure used in the study was the MCID. We performed an extensive literature search of a series of meta-analyses evaluating a similar subject as an example. We searched in Pubmed and Embase through August 9, 2016, and found articles concerning meta-analyses of the clinical outcome of cervical arthroplasty compared with that of anterior cervical discectomy with fusion in cases of cervical degenerative disease. We evaluated the analyses for statistical significance and their relation to MCID. MCID was defined based on results in similar patient groups and a similar disease entity reported in the literature. We identified 21 meta-analyses, only one of which referred to MCID. However, the researchers used an inappropriate measurement scale and, therefore, an incorrect MCID. The majority of the conclusions were based on statistical results without mentioning clinical relevance. The majority of the articles we reviewed drew conclusions based on statistical differences instead of clinical relevance. We recommend introducing the concept of MCID while reporting the results of a meta-analysis, as well as mentioning the explicit scale of the analyzed measurement. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Environmental risk factors of pregnancy outcomes: a summary of recent meta-analyses of epidemiological studies.

    Science.gov (United States)

    Nieuwenhuijsen, Mark J; Dadvand, Payam; Grellier, James; Martinez, David; Vrijheid, Martine

    2013-01-15

    Various epidemiological studies have suggested associations between environmental exposures and pregnancy outcomes. Some studies have tempted to combine information from various epidemiological studies using meta-analysis. We aimed to describe the methodologies used in these recent meta-analyses of environmental exposures and pregnancy outcomes. Furthermore, we aimed to report their main findings. We conducted a bibliographic search with relevant search terms. We obtained and evaluated 16 recent meta-analyses. The number of studies included in each reported meta-analysis varied greatly, with the largest number of studies available for environmental tobacco smoke. Only a small number of the studies reported having followed meta-analysis guidelines or having used a quality rating system. Generally they tested for heterogeneity and publication bias. Publication bias did not occur frequently.The meta-analyses found statistically significant negative associations between environmental tobacco smoke and stillbirth, birth weight and any congenital anomalies; PM2.5 and preterm birth; outdoor air pollution and some congenital anomalies; indoor air pollution from solid fuel use and stillbirth and birth weight; polychlorinated biphenyls (PCB) exposure and birth weight; disinfection by-products in water and stillbirth, small for gestational age and some congenital anomalies; occupational exposure to pesticides and solvents and some congenital anomalies; and agent orange and some congenital anomalies. The number of meta-analyses of environmental exposures and pregnancy outcomes is small and they vary in methodology. They reported statistically significant associations between environmental exposures such as environmental tobacco smoke, air pollution and chemicals and pregnancy outcomes.

  8. Environmental risk factors of pregnancy outcomes: a summary of recent meta-analyses of epidemiological studies

    Directory of Open Access Journals (Sweden)

    Nieuwenhuijsen Mark J

    2013-01-01

    Full Text Available Abstract Background Various epidemiological studies have suggested associations between environmental exposures and pregnancy outcomes. Some studies have tempted to combine information from various epidemiological studies using meta-analysis. We aimed to describe the methodologies used in these recent meta-analyses of environmental exposures and pregnancy outcomes. Furthermore, we aimed to report their main findings. Methods We conducted a bibliographic search with relevant search terms. We obtained and evaluated 16 recent meta-analyses. Results The number of studies included in each reported meta-analysis varied greatly, with the largest number of studies available for environmental tobacco smoke. Only a small number of the studies reported having followed meta-analysis guidelines or having used a quality rating system. Generally they tested for heterogeneity and publication bias. Publication bias did not occur frequently. The meta-analyses found statistically significant negative associations between environmental tobacco smoke and stillbirth, birth weight and any congenital anomalies; PM2.5 and preterm birth; outdoor air pollution and some congenital anomalies; indoor air pollution from solid fuel use and stillbirth and birth weight; polychlorinated biphenyls (PCB exposure and birth weight; disinfection by-products in water and stillbirth, small for gestational age and some congenital anomalies; occupational exposure to pesticides and solvents and some congenital anomalies; and agent orange and some congenital anomalies. Conclusions The number of meta-analyses of environmental exposures and pregnancy outcomes is small and they vary in methodology. They reported statistically significant associations between environmental exposures such as environmental tobacco smoke, air pollution and chemicals and pregnancy outcomes.

  9. Effect of periodontal treatment on preterm birth rate: a systematic review of meta-analyses.

    Science.gov (United States)

    López, Néstor J; Uribe, Sergio; Martinez, Benjamín

    2015-02-01

    Preterm birth is a major cause of neonatal morbidity and mortality in both developed and developing countries. Preterm birth is a highly complex syndrome that includes distinct clinical subtypes in which many different causes may be involved. The results of epidemiological, molecular, microbiological and animal-model studies support a positive association between maternal periodontal disease and preterm birth. However, the results of intervention studies carried out to determine the effect of periodontal treatment on reducing the risk of preterm birth are controversial. This systematic review critically analyzes the methodological issues of meta-analyses of the studies to determine the effect of periodontal treatment to reduce preterm birth. The quality of the individual randomized clinical trials selected is of highest relevance for a systematic review. This article describes the methodological features that should be identified a priori and assessed individually to determine the quality of a randomized controlled trial performed to evaluate the effect of periodontal treatment on pregnancy outcomes. The AMSTAR and the PRISMA checklist tools were used to assess the quality of the six meta-analyses selected, and the bias domain of the Cochrane Collaboration's Tool was applied to evaluate each of the trials included in the meta-analyses. In addition, the methodological characteristics of each clinical trial were assessed. The majority of the trials included in the meta-analyses have significant methodological flaws that threaten their internal validity. The lack of effect of periodontal treatment on preterm birth rate concluded by four meta-analyses, and the positive effect of treatment for reducing preterm birth risk concluded by the remaining two meta-analyses are not based on consistent scientific evidence. Well-conducted randomized controlled trials using rigorous methodology, including appropriate definition of the exposure, adequate control of confounders for

  10. Novel citation-based search method for scientific literature: application to meta-analyses.

    Science.gov (United States)

    Janssens, A Cecile J W; Gwinn, M

    2015-10-13

    Finding eligible studies for meta-analysis and systematic reviews relies on keyword-based searching as the gold standard, despite its inefficiency. Searching based on direct citations is not sufficiently comprehensive. We propose a novel strategy that ranks articles on their degree of co-citation with one or more "known" articles before reviewing their eligibility. In two independent studies, we aimed to reproduce the results of literature searches for sets of published meta-analyses (n = 10 and n = 42). For each meta-analysis, we extracted co-citations for the randomly selected 'known' articles from the Web of Science database, counted their frequencies and screened all articles with a score above a selection threshold. In the second study, we extended the method by retrieving direct citations for all selected articles. In the first study, we retrieved 82% of the studies included in the meta-analyses while screening only 11% as many articles as were screened for the original publications. Articles that we missed were published in non-English languages, published before 1975, published very recently, or available only as conference abstracts. In the second study, we retrieved 79% of included studies while screening half the original number of articles. Citation searching appears to be an efficient and reasonably accurate method for finding articles similar to one or more articles of interest for meta-analysis and reviews.

  11. Quality control and conduct of genome-wide association meta-analyses

    DEFF Research Database (Denmark)

    Winkler, Thomas W; Day, Felix R; Croteau-Chonka, Damien C

    2014-01-01

    Rigorous organization and quality control (QC) are necessary to facilitate successful genome-wide association meta-analyses (GWAMAs) of statistics aggregated across multiple genome-wide association studies. This protocol provides guidelines for (i) organizational aspects of GWAMAs, and for (ii) QC...

  12. A systematic meta-review of evaluations of youth violence prevention programs: Common and divergent findings from 25 years of meta-analyses and systematic reviews☆

    Science.gov (United States)

    Matjasko, Jennifer L.; Vivolo-Kantor, Alana M.; Massetti, Greta M.; Holland, Kristin M.; Holt, Melissa K.; Cruz, Jason Dela

    2018-01-01

    Violence among youth is a pervasive public health problem. In order to make progress in reducing the burden of injury and mortality that result from youth violence, it is imperative to identify evidence-based programs and strategies that have a significant impact on violence. There have been many rigorous evaluations of youth violence prevention programs. However, the literature is large, and it is difficult to draw conclusions about what works across evaluations from different disciplines, contexts, and types of programs. The current study reviews the meta-analyses and systematic reviews published prior to 2009 that synthesize evaluations of youth violence prevention programs. This meta-review reports the findings from 37 meta-analyses and 15 systematic reviews; the included reviews were coded on measures of the social ecology, prevention approach, program type, and study design. A majority of the meta-analyses and systematic reviews were found to demonstrate moderate program effects. Meta-analyses yielded marginally smaller effect sizes compared to systematic reviews, and those that included programs targeting family factors showed marginally larger effects than those that did not. In addition, there are a wide range of individual/family, program, and study moderators of program effect sizes. Implications of these findings and suggestions for future research are discussed. PMID:29503594

  13. Robustness assessments are needed to reduce bias in meta-analyses that include zero-event randomized trials

    DEFF Research Database (Denmark)

    Keus, F; Wetterslev, J; Gluud, C

    2009-01-01

    of statistical method on inference. RESULTS: In seven meta-analyses of seven outcomes from 15 trials, there were zero-event trials in 0 to 71.4% of the trials. We found inconsistency in significance in one of seven outcomes (14%; 95% confidence limit 0.4%-57.9%). There was also considerable variability......OBJECTIVES: Meta-analysis of randomized trials with binary data can use a variety of statistical methods. Zero-event trials may create analytic problems. We explored how different methods may impact inferences from meta-analyses containing zero-event trials. METHODS: Five levels of statistical...... methods are identified for meta-analysis with zero-event trials, leading to numerous data analyses. We used the binary outcomes from our Cochrane review of randomized trials of laparoscopic vs. small-incision cholecystectomy for patients with symptomatic cholecystolithiasis to illustrate the influence...

  14. Characteristics of meta-analyses and their component studies in the Cochrane Database of Systematic Reviews: a cross-sectional, descriptive analysis

    Directory of Open Access Journals (Sweden)

    Davey Jonathan

    2011-11-01

    Full Text Available Abstract Background Cochrane systematic reviews collate and summarise studies of the effects of healthcare interventions. The characteristics of these reviews and the meta-analyses and individual studies they contain provide insights into the nature of healthcare research and important context for the development of relevant statistical and other methods. Methods We classified every meta-analysis with at least two studies in every review in the January 2008 issue of the Cochrane Database of Systematic Reviews (CDSR according to the medical specialty, the types of interventions being compared and the type of outcome. We provide descriptive statistics for numbers of meta-analyses, numbers of component studies and sample sizes of component studies, broken down by these categories. Results We included 2321 reviews containing 22,453 meta-analyses, which themselves consist of data from 112,600 individual studies (which may appear in more than one meta-analysis. Meta-analyses in the areas of gynaecology, pregnancy and childbirth (21%, mental health (13% and respiratory diseases (13% are well represented in the CDSR. Most meta-analyses address drugs, either with a control or placebo group (37% or in a comparison with another drug (25%. The median number of meta-analyses per review is six (inter-quartile range 3 to 12. The median number of studies included in the meta-analyses with at least two studies is three (inter-quartile range 2 to 6. Sample sizes of individual studies range from 2 to 1,242,071, with a median of 91 participants. Discussion It is clear that the numbers of studies eligible for meta-analyses are typically very small for all medical areas, outcomes and interventions covered by Cochrane reviews. This highlights the particular importance of suitable methods for the meta-analysis of small data sets. There was little variation in number of studies per meta-analysis across medical areas, across outcome data types or across types of

  15. A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses

    Science.gov (United States)

    Esposito, Katherine; Maiorino, Maria Ida; Bellastella, Giuseppe; Chiodini, Paolo; Panagiotakos, Demosthenes; Giugliano, Dario

    2015-01-01

    Objectives To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states. Design A systematic review of all meta-analyses and randomised controlled trials (RCTs) that compared the Mediterranean diet with a control diet on the treatment of type 2 diabetes and prediabetic states was conducted. Electronic searches were carried out up to January 2015. Trials were included for meta-analyses if they had a control group treated with another diet, if they were of sufficient duration (at least 6 months), and if they had at least 30 participants in each arm. A random-effect model was used to pool data. Participants Adults with or at risk for type 2 diabetes. Interventions Dietary patterns that described themselves as using a ‘Mediterranean’ dietary pattern. Outcome measures The outcomes were glycaemic control, cardiovascular risk factors and remission from the metabolic syndrome. Results From 2824 studies, 8 meta-analyses and 5 RCTs were eligible. A ‘de novo’ meta-analysis of 3 long-term (>6 months) RCTs of the Mediterranean diet and glycaemic control of diabetes favoured the Mediterranean diet as compared with lower fat diets. Another ‘de novo’ meta-analysis of two long-term RCTs showed a 49% increased probability of remission from the metabolic syndrome. 5 meta-analyses showed a favourable effect of the Mediterranean diet, as compared with other diets, on body weight, total cholesterol and high-density lipoprotein cholesterol. 2 meta-analyses demonstrated that higher adherence to the Mediterranean diet reduced the risk of future diabetes by 19–23%. Conclusions The Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes. PMID:26260349

  16. [Considerations on the use of meta-analyses in the orientation of knowledge and decisions in Occupational Medicine].

    Science.gov (United States)

    Catalani, Simona; Berra, Alessandro; Tomasi, Cesare; Romano, Canzio; Pira, Enrico; Garzaro, Giacomo; Apostoli, Pietro

    2015-01-01

    In recent years, due to the need to elaborate the amount of information available from the scientific literature, the meta-analyses and systematic reviews have become very numerous. The meta-analyses are carried out to evaluate the association between two events when single researches haven't provided comprehensive data. On the other hand, a good meta-analysis must satisfy certain criteria, from the selection of the studies until the evaluation of the outcomes; to this purpose, the application of methods for quality assessment is a crucial point to obtain data of adequate reliability. The aim of this review is to give some introductory tools for a critical approach to meta-analyses and systematic reviews, which have become useful instruments also in occupational medicine.

  17. Weighing Evidence "Steampunk" Style via the Meta-Analyser.

    Science.gov (United States)

    Bowden, Jack; Jackson, Chris

    2016-10-01

    The funnel plot is a graphical visualization of summary data estimates from a meta-analysis, and is a useful tool for detecting departures from the standard modeling assumptions. Although perhaps not widely appreciated, a simple extension of the funnel plot can help to facilitate an intuitive interpretation of the mathematics underlying a meta-analysis at a more fundamental level, by equating it to determining the center of mass of a physical system. We used this analogy to explain the concepts of weighing evidence and of biased evidence to a young audience at the Cambridge Science Festival, without recourse to precise definitions or statistical formulas and with a little help from Sherlock Holmes! Following on from the science fair, we have developed an interactive web-application (named the Meta-Analyser) to bring these ideas to a wider audience. We envisage that our application will be a useful tool for researchers when interpreting their data. First, to facilitate a simple understanding of fixed and random effects modeling approaches; second, to assess the importance of outliers; and third, to show the impact of adjusting for small study bias. This final aim is realized by introducing a novel graphical interpretation of the well-known method of Egger regression.

  18. Circulating biomarkers for predicting cardiovascular disease risk; a systematic review and comprehensive overview of meta-analyses.

    Directory of Open Access Journals (Sweden)

    Thijs C van Holten

    Full Text Available BACKGROUND: Cardiovascular disease is one of the major causes of death worldwide. Assessing the risk for cardiovascular disease is an important aspect in clinical decision making and setting a therapeutic strategy, and the use of serological biomarkers may improve this. Despite an overwhelming number of studies and meta-analyses on biomarkers and cardiovascular disease, there are no comprehensive studies comparing the relevance of each biomarker. We performed a systematic review of meta-analyses on levels of serological biomarkers for atherothrombosis to compare the relevance of the most commonly studied biomarkers. METHODS AND FINDINGS: Medline and Embase were screened on search terms that were related to "arterial ischemic events" and "meta-analyses". The meta-analyses were sorted by patient groups without pre-existing cardiovascular disease, with cardiovascular disease and heterogeneous groups concerning general populations, groups with and without cardiovascular disease, or miscellaneous. These were subsequently sorted by end-point for cardiovascular disease or stroke and summarized in tables. We have identified 85 relevant full text articles, with 214 meta-analyses. Markers for primary cardiovascular events include, from high to low result: C-reactive protein, fibrinogen, cholesterol, apolipoprotein B, the apolipoprotein A/apolipoprotein B ratio, high density lipoprotein, and vitamin D. Markers for secondary cardiovascular events include, from high to low result: cardiac troponins I and T, C-reactive protein, serum creatinine, and cystatin C. For primary stroke, fibrinogen and serum uric acid are strong risk markers. Limitations reside in that there is no acknowledged search strategy for prognostic studies or meta-analyses. CONCLUSIONS: For primary cardiovascular events, markers with strong predictive potential are mainly associated with lipids. For secondary cardiovascular events, markers are more associated with ischemia. Fibrinogen is a

  19. Conclusive meta-analyses on antenatal magnesium may be inconclusive! Are we underestimating the risk of random error?

    DEFF Research Database (Denmark)

    Brok, Jesper; Huusom, Lene D; Thorlund, Kristian

    2012-01-01

    Results from meta-analyses significantly influence clinical practice. Both simulation and empirical studies have demonstrated that the risk of random error (i.e. spurious chance findings) in meta-analyses is much higher than previously anticipated. Hence, authors and users of systematic reviews a...... about the investigated intervention effect(s). We outline the rationale for conducting trial sequential analysis including some examples of the meta-analysis on antenatal magnesium for women at risk of preterm birth....

  20. Efficacy of adjuvant chemotherapy after surgery when considered over all cancer types: a synthesis of meta-analyses.

    Science.gov (United States)

    Bowater, Russell J; Abdelmalik, Sally M E; Lilford, Richard J

    2012-10-01

    Despite a large number of clinical trials having been conducted to assess the efficacy of adjuvant chemotherapy after surgery for various cancers, whether it is best to use this treatment remains a generally contentious issue for many common cancers. The purpose of this study was to ascertain whether any general conclusions can be drawn about the efficacy or inefficacy of this treatment within different cancer classifications. Meta-analyses of randomized, controlled trials (RCTs) of adjuvant chemotherapy after surgery were synthesized over as many types of cancer as possible. Data sources were Medline, Embase, and the Cochrane library. Eligible meta-analyses were meta-analyses of RCTs for any type of cancer that compared surgery followed by adjuvant chemotherapy with surgery followed by no adjuvant chemotherapy. The literature search found 25 meta-analyses for 15 cancer types that satisfied the criteria necessary for detailed analysis within this study. The estimates of relative risk for all cause mortality were reported as being less than one (indicating adjuvant chemotherapy is beneficial) by all meta-analyses apart from a meta-analysis for colorectal cancer metastasized to the liver. Moreover, 15 of these meta-analyses also reported that the 95% confidence interval for this relative risk is less than one (indicating statistical significance at the 5% level). The results for all cancer types included in this study except for cancer metastasized to the liver can be thought of as supporting each other through the idea of there being a common treatment effect or at least a common range of effect across all (or most) of these cancer types. For example, with regard to cancer types where the evidence in favor of adjuvant chemotherapy after surgery is only moderately strong, the results of this study may encourage more clinicians to regard the use of this treatment as standard practice.

  1. Grey literature in meta-analyses of randomized trials of health care interventions.

    Science.gov (United States)

    Hopewell, S; McDonald, S; Clarke, M; Egger, M

    2007-04-18

    The inclusion of grey literature (i.e. literature that has not been formally published) in systematic reviews may help to overcome some of the problems of publication bias, which can arise due to the selective availability of data. To review systematically research studies, which have investigated the impact of grey literature in meta-analyses of randomized trials of health care interventions. We searched the Cochrane Methodology Register (The Cochrane Library Issue 3, 2005), MEDLINE (1966 to 20 May 2005), the Science Citation Index (June 2005) and contacted researchers who may have carried out relevant studies. A study was considered eligible for this review if it compared the effect of the inclusion and exclusion of grey literature on the results of a cohort of meta-analyses of randomized trials. Data were extracted from each report independently by two reviewers. The main outcome measure was an estimate of the impact of trials from the grey literature on the pooled effect estimates of the meta-analyses. Information was also collected on the area of health care, the number of meta-analyses, the number of trials, the number of trial participants, the year of publication of the trials, the language and country of publication of the trials, the number and type of grey and published literature, and methodological quality. Five studies met the inclusion criteria. All five studies showed that published trials showed an overall greater treatment effect than grey trials. This difference was statistically significant in one of the five studies. Data could be combined for three of the five studies. This showed that, on average, published trials showed a 9% greater treatment effect than grey trials (ratio of odds ratios for grey versus published trials 1.09; 95% CI 1.03-1.16). Overall there were more published trials included in the meta-analyses than grey trials (median 224 (IQR 108-365) versus 45(IQR 40-102)). Published trials had more participants on average. The most

  2. A journey into a Mediterranean diet and type 2 diabetes: a systematic review with meta-analyses.

    Science.gov (United States)

    Esposito, Katherine; Maiorino, Maria Ida; Bellastella, Giuseppe; Chiodini, Paolo; Panagiotakos, Demosthenes; Giugliano, Dario

    2015-08-10

    To summarise the evidence about the efficacy of a Mediterranean diet on the management of type 2 diabetes and prediabetic states. A systematic review of all meta-analyses and randomised controlled trials (RCTs) that compared the Mediterranean diet with a control diet on the treatment of type 2 diabetes and prediabetic states was conducted. Electronic searches were carried out up to January 2015. Trials were included for meta-analyses if they had a control group treated with another diet, if they were of sufficient duration (at least 6 months), and if they had at least 30 participants in each arm. A random-effect model was used to pool data. Adults with or at risk for type 2 diabetes. Dietary patterns that described themselves as using a 'Mediterranean' dietary pattern. The outcomes were glycaemic control, cardiovascular risk factors and remission from the metabolic syndrome. From 2824 studies, 8 meta-analyses and 5 RCTs were eligible. A 'de novo' meta-analysis of 3 long-term (>6 months) RCTs of the Mediterranean diet and glycaemic control of diabetes favoured the Mediterranean diet as compared with lower fat diets. Another 'de novo' meta-analysis of two long-term RCTs showed a 49% increased probability of remission from the metabolic syndrome. 5 meta-analyses showed a favourable effect of the Mediterranean diet, as compared with other diets, on body weight, total cholesterol and high-density lipoprotein cholesterol. 2 meta-analyses demonstrated that higher adherence to the Mediterranean diet reduced the risk of future diabetes by 19-23%. The Mediterranean diet was associated with better glycaemic control and cardiovascular risk factors than control diets, including a lower fat diet, suggesting that it is suitable for the overall management of type 2 diabetes. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. The interrelation between hypothyroidism and glaucoma: a critical review and meta-analyses.

    Science.gov (United States)

    Thvilum, Marianne; Brandt, Frans; Brix, Thomas Heiberg; Hegedüs, Laszlo

    2017-12-01

    Data on the association between hypothyroidism and glaucoma are conflicting. We sought to shed light on this by conducting a critical review and meta-analyses. The meta-analyses were conducted in adherence with the widely accepted MOOSE guidelines. Using the Medical Subject Heading (MeSH) terms: hypothyroidism, myxoedema and glaucoma or intraocular pressure, case-control studies, cohort studies and cross-sectional studies were identified (PubMed) and reviewed. Using meta-analysis, the relative risk (RR) of coexistence of glaucoma and hypothyroidism was calculated. Based on the literature search, thirteen studies fulfilled the inclusion criteria and could be categorized into two groups based on the exposure. The designs of the studies varied considerably, and there was heterogeneity related to lack of power, weak phenotype classifications and length of follow-up. Eight studies had glaucoma (5757 patients) as exposure and hypothyroidism as outcome. Among these, we found a non-significantly increased risk of hypothyroidism associated with glaucoma (RR 1.65; 95% confidence interval [CI]: 0.97-2.82). Based on five studies (168 006 patients) with hypothyroidism as exposure and glaucoma as outcome, we found the risk of glaucoma to be significantly increased (RR 1.33; 95% CI: 1.13-1.58). Based on these meta-analyses, there seems to be an association between hypothyroidism and glaucoma, which does not seem to be the case between glaucoma and hypothyroidism. However, larger scale studies with better phenotype classification, longer follow-up and taking comorbidity and other biases into consideration are needed to address a potential causal relationship. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  4. Using meta-analytic path analysis to test theoretical predictions in health behavior: An illustration based on meta-analyses of the theory of planned behavior

    OpenAIRE

    Hagger, Martin; Chan, Dervin K. C.; Protogerou, Cleo; Chatzisarantis, Nikos L. D.

    2016-01-01

    Objective Synthesizing research on social cognitive theories applied to health behavior is an important step in the development of an evidence base of psychological factors as targets for effective behavioral interventions. However, few meta-analyses of research on social cognitive theories in health contexts have conducted simultaneous tests of theoretically-stipulated pattern effects using path analysis. We argue that conducting path analyses of meta-analytic effects among constructs fr...

  5. Oral Chinese proprietary medicine for angina pectoris: an overview of systematic reviews/meta-analyses.

    Science.gov (United States)

    Luo, Jing; Xu, Hao; Yang, Guoyan; Qiu, Yu; Liu, Jianping; Chen, Keji

    2014-08-01

    Oral Chinese proprietary medicine (CPM) is commonly used to treat angina pectoris, and many relevant systematic reviews/meta-analyses are available. However, these reviews have not been systematically summarized and evaluated. We conducted an overview of these reviews, and explored their methodological and reporting quality to inform both practice and further research. We included systematic reviews/meta-analyses on oral CPM in treating angina until March 2013 by searching PubMed, Embase, the Cochrane Library and four Chinese databases. We extracted data according to a pre-designed form, and assessed the methodological and reporting characteristics of the reviews in terms of AMSTAR and PRISMA respectively. Most of the data analyses were descriptive. 36 systematic reviews/meta-analyses involving over 82,105 participants with angina reviewing 13 kinds of oral CPM were included. The main outcomes assessed in the reviews were surrogate outcomes (34/36, 94.4%), adverse events (31/36, 86.1%), and symptoms (30/36, 83.3%). Six reviews (6/36, 16.7%) drew definitely positive conclusions, while the others suggested potential benefits in the symptoms, electrocardiogram, and adverse events. The overall methodological and reporting quality of the reviews was limited, with many serious flaws such as the lack of review protocol and incomprehensive literature searches. Though many systematic reviews/meta-analyses on oral CPM for angina suggested potential benefits or definitely positive effects, stakeholders should interpret the findings of these reviews with caution, considering the overall limited methodological and reporting quality. We recommend further studies should be appropriately conducted and systematic reviews reported according to PRISMA standard. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Genome-wide meta-analyses identify multiple loci associated with smoking behavior

    NARCIS (Netherlands)

    H. Furberg (Helena); Y. Kim (Yunjung); J. Dackor (Jennifer); E.A. Boerwinkle (Eric); N. Franceschini (Nora); D. Ardissino (Diego); L. Bernardinelli (Luisa); P.M. Mannucci (Pier); F. Mauri (Francesco); P.A. Merlini (Piera); D. Absher (Devin); T.L. Assimes (Themistocles); S.P. Fortmann (Stephen); C. Iribarren (Carlos); J.W. Knowles (Joshua); T. Quertermous (Thomas); L. Ferrucci (Luigi); T. Tanaka (Toshiko); J.C. Bis (Joshua); T. Haritunians (Talin); B. McKnight (Barbara); B.M. Psaty (Bruce); K.D. Taylor (Kent); E.L. Thacker (Evan); P. Almgren (Peter); L. Groop (Leif); C. Ladenvall (Claes); M. Boehnke (Michael); A.U. Jackson (Anne); K.L. Mohlke (Karen); H.M. Stringham (Heather); J. Tuomilehto (Jaakko); E.J. Benjamin (Emelia); S.J. Hwang; D. Levy (Daniel); S.R. Preis; R.S. Vasan (Ramachandran Srini); J. Duan (Jubao); P.V. Gejman (Pablo); D.F. Levinson (Douglas); A.R. Sanders (Alan); J. Shi (Jianxin); E.H. Lips (Esther); J.D. McKay (James); A. Agudo (Antonio); L. Barzan (Luigi); V. Bencko (Vladimir); S. Benhamou (Simone); X. Castellsagué (Xavier); C. Canova (Cristina); D.I. Conway (David); E. Fabianova (Eleonora); L. Foretova (Lenka); V. Janout (Vladimir); C.M. Healy (Claire); I. Holcátová (Ivana); K. Kjaerheim (Kristina); P. Lagiou; J. Lissowska (Jolanta); R. Lowry (Ray); T.V. MacFarlane (Tatiana); D. Mates (Dana); L. Richiardi (Lorenzo); P. Rudnai (Peter); N. Szeszenia-Dabrowska (Neonilia); D. Zaridze; A. Znaor (Ariana); M. Lathrop (Mark); P. Brennan (Paul); S. Bandinelli (Stefania); T.M. Frayling (Timothy); J.M. Guralnik (Jack); Y. Milaneschi (Yuri); J.R.B. Perry (John); D. Altshuler (David); R. Elosua (Roberto); S. Kathiresan (Sekar); G. Lucas (Gavin); O. Melander (Olle); V. Salomaa (Veikko); S.M. Schwartz (Stephen); B.F. Voight (Benjamin); B.W.J.H. Penninx (Brenda); J.H. Smit (Johannes); N. Vogelzangs (Nicole); D.I. Boomsma (Dorret); E.J.C. de Geus (Eco); J.M. Vink (Jacqueline); G.A.H.M. Willemsen (Gonneke); S.J. Chanock (Stephen); F. Gu (Fangyi); S.E. Hankinson (Susan); D. Hunter (David); A. Hofman (Albert); H.W. Tiemeier (Henning); A.G. Uitterlinden (André); P. Tikka-Kleemola (Päivi); S. Walter (Stefan); D.I. Chasman (Daniel); B.M. Everett (Brendan); G. Pare (Guillaume); P.M. Ridker (Paul); M.D. Li (Ming); H.H. Maes (Hermine); J. Audrain-Mcgovern (Janet); D. Posthuma (Danielle); L.M. Thornton (Laura); C. Lerman (Caryn); J. Kaprio (Jaakko); J.E. Rose (Jed); J.P.A. Ioannidis (John); P. Kraft (Peter); D.Y. Lin (Dan); P.F. Sullivan (Patrick); C.J. O'Donnell (Christopher)

    2010-01-01

    textabstractConsistent but indirect evidence has implicated genetic factors in smoking behavior. We report meta-analyses of several smoking phenotypes within cohorts of the Tobacco and Genetics Consortium (n = 74,053). We also partnered with the European Network of Genetic and Genomic Epidemiology

  7. Estimating required information size by quantifying diversity in random-effects model meta-analyses

    DEFF Research Database (Denmark)

    Wetterslev, Jørn; Thorlund, Kristian; Brok, Jesper

    2009-01-01

    an intervention effect suggested by trials with low-risk of bias. METHODS: Information size calculations need to consider the total model variance in a meta-analysis to control type I and type II errors. Here, we derive an adjusting factor for the required information size under any random-effects model meta......-analysis. RESULTS: We devise a measure of diversity (D2) in a meta-analysis, which is the relative variance reduction when the meta-analysis model is changed from a random-effects into a fixed-effect model. D2 is the percentage that the between-trial variability constitutes of the sum of the between...... and interpreted using several simulations and clinical examples. In addition we show mathematically that diversity is equal to or greater than inconsistency, that is D2 >or= I2, for all meta-analyses. CONCLUSION: We conclude that D2 seems a better alternative than I2 to consider model variation in any random...

  8. Contour plot assessment of existing meta-analyses confirms robust association of statin use and acute kidney injury risk.

    Science.gov (United States)

    Chevance, Aurélie; Schuster, Tibor; Steele, Russell; Ternès, Nils; Platt, Robert W

    2015-10-01

    Robustness of an existing meta-analysis can justify decisions on whether to conduct an additional study addressing the same research question. We illustrate the graphical assessment of the potential impact of an additional study on an existing meta-analysis using published data on statin use and the risk of acute kidney injury. A previously proposed graphical augmentation approach is used to assess the sensitivity of the current test and heterogeneity statistics extracted from existing meta-analysis data. In addition, we extended the graphical augmentation approach to assess potential changes in the pooled effect estimate after updating a current meta-analysis and applied the three graphical contour definitions to data from meta-analyses on statin use and acute kidney injury risk. In the considered example data, the pooled effect estimates and heterogeneity indices demonstrated to be considerably robust to the addition of a future study. Supportingly, for some previously inconclusive meta-analyses, a study update might yield statistically significant kidney injury risk increase associated with higher statin exposure. The illustrated contour approach should become a standard tool for the assessment of the robustness of meta-analyses. It can guide decisions on whether to conduct additional studies addressing a relevant research question. Copyright © 2015 Elsevier Inc. All rights reserved.

  9. Cost-Benefit Analyses of Transportation Investments

    DEFF Research Database (Denmark)

    Næss, Petter

    2006-01-01

    This paper discusses the practice of cost-benefit analyses of transportation infrastructure investment projects from the meta-theoretical perspective of critical realism. Such analyses are based on a number of untenable ontological assumptions about social value, human nature and the natural......-to-pay investigations. Accepting the ontological and epistemological assumptions of cost-benefit analysis involves an implicit acceptance of the ethical and political values favoured by these assumptions. Cost-benefit analyses of transportation investment projects tend to neglect long-term environmental consequences...

  10. Meta-connectomics: human brain network and connectivity meta-analyses.

    Science.gov (United States)

    Crossley, N A; Fox, P T; Bullmore, E T

    2016-04-01

    Abnormal brain connectivity or network dysfunction has been suggested as a paradigm to understand several psychiatric disorders. We here review the use of novel meta-analytic approaches in neuroscience that go beyond a summary description of existing results by applying network analysis methods to previously published studies and/or publicly accessible databases. We define this strategy of combining connectivity with other brain characteristics as 'meta-connectomics'. For example, we show how network analysis of task-based neuroimaging studies has been used to infer functional co-activation from primary data on regional activations. This approach has been able to relate cognition to functional network topology, demonstrating that the brain is composed of cognitively specialized functional subnetworks or modules, linked by a rich club of cognitively generalized regions that mediate many inter-modular connections. Another major application of meta-connectomics has been efforts to link meta-analytic maps of disorder-related abnormalities or MRI 'lesions' to the complex topology of the normative connectome. This work has highlighted the general importance of network hubs as hotspots for concentration of cortical grey-matter deficits in schizophrenia, Alzheimer's disease and other disorders. Finally, we show how by incorporating cellular and transcriptional data on individual nodes with network models of the connectome, studies have begun to elucidate the microscopic mechanisms underpinning the macroscopic organization of whole-brain networks. We argue that meta-connectomics is an exciting field, providing robust and integrative insights into brain organization that will likely play an important future role in consolidating network models of psychiatric disorders.

  11. How can my research paper be useful for future meta-analyses on forest restoration practices?

    Science.gov (United States)

    Enrique Andivia; Pedro Villar‑Salvador; Juan A. Oliet; Jaime Puertolas; R. Kasten Dumroese

    2018-01-01

    Statistical meta-analysis is a powerful and useful tool to quantitatively synthesize the information conveyed in published studies on a particular topic. It allows identifying and quantifying overall patterns and exploring causes of variation. The inclusion of published works in meta-analyses requires, however, a minimum quality standard of the reported data and...

  12. The effect of English-language restriction on systematic review-based meta-analyses: a systematic review of empirical studies.

    Science.gov (United States)

    Morrison, Andra; Polisena, Julie; Husereau, Don; Moulton, Kristen; Clark, Michelle; Fiander, Michelle; Mierzwinski-Urban, Monika; Clifford, Tammy; Hutton, Brian; Rabb, Danielle

    2012-04-01

    The English language is generally perceived to be the universal language of science. However, the exclusive reliance on English-language studies may not represent all of the evidence. Excluding languages other than English (LOE) may introduce a language bias and lead to erroneous conclusions. We conducted a comprehensive literature search using bibliographic databases and grey literature sources. Studies were eligible for inclusion if they measured the effect of excluding randomized controlled trials (RCTs) reported in LOE from systematic review-based meta-analyses (SR/MA) for one or more outcomes. None of the included studies found major differences between summary treatment effects in English-language restricted meta-analyses and LOE-inclusive meta-analyses. Findings differed about the methodological and reporting quality of trials reported in LOE. The precision of pooled estimates improved with the inclusion of LOE trials. Overall, we found no evidence of a systematic bias from the use of language restrictions in systematic review-based meta-analyses in conventional medicine. Further research is needed to determine the impact of language restriction on systematic reviews in particular fields of medicine.

  13. Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer : Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses

    NARCIS (Netherlands)

    Khankari, Nikhil K.; Shu, Xiao Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I.; Easton, Douglas; Eeles, Rosalind A.; Gruber, Stephen B.; Haiman, Christopher A.; Hunter, David J.; Chanock, Stephen J.; Pierce, Brandon L.; Zheng, Wei; Blalock, Kendra; Campbell, Peter T.; Casey, Graham; Conti, David V.; Edlund, Christopher K.; Figueiredo, Jane; James Gauderman, W.; Gong, Jian; Green, Roger C.; Harju, John F.; Harrison, Tabitha A.; Jacobs, Eric J.; Jenkins, Mark A.; Jiao, Shuo; Li, Li; Lin, Yi; Manion, Frank J.; Moreno, Victor; Mukherjee, Bhramar; Raskin, Leon; Schumacher, Fredrick R.; Seminara, Daniela; Severi, Gianluca; Stenzel, Stephanie L.; Thomas, Duncan C.; Hopper, John L.; Southey, Melissa C.; Makalic, Enes; Schmidt, Daniel F.; Fletcher, Olivia; Peto, Julian; Gibson, Lorna; dos Santos Silva, Isabel; Ahsan, Habib; Whittemore, Alice; Waisfisz, Quinten; Meijers-Heijboer, Hanne; Adank, Muriel; van der Luijt, Rob B.; Uitterlinden, Andre G.; Hofman, Albert; Meindl, Alfons; Schmutzler, Rita K.; Müller-Myhsok, Bertram; Lichtner, Peter; Nevanlinna, Heli; Muranen, Taru A.; Aittomäki, Kristiina; Blomqvist, Carl; Chang-Claude, Jenny; Hein, Rebecca; Dahmen, Norbert; Beckman, Lars; Crisponi, Laura; Hall, Per; Czene, Kamila; Irwanto, Astrid; Liu, Jianjun; Easton, Douglas F.; Turnbull, Clare; Rahman, Nazneen; Eeles, Rosalind; Kote-Jarai, Zsofia; Muir, Kenneth; Giles, Graham; Neal, David; Donovan, Jenny L.; Hamdy, Freddie C.; Wiklund, Fredrik; Gronberg, Henrik; Haiman, Christopher; Schumacher, Fred; Travis, Ruth; Riboli, Elio; Hunter, David; Gapstur, Susan; Berndt, Sonja; Chanock, Stephen; Han, Younghun; Su, Li; Wei, Yongyue; Hung, Rayjean J.; Brhane, Yonathan; McLaughlin, John; Brennan, Paul; McKay, James D.; Rosenberger, Albert; Houlston, Richard S.; Caporaso, Neil; Teresa Landi, Maria; Heinrich, Joachim; Wu, Xifeng; Ye, Yuanqing; Christiani, David C.

    2016-01-01

    Background: Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using

  14. Effect size calculation in meta-analyses of psychotherapy outcome research.

    Science.gov (United States)

    Hoyt, William T; Del Re, A C

    2018-05-01

    Meta-analysis of psychotherapy intervention research normally examines differences between treatment groups and some form of comparison group (e.g., wait list control; alternative treatment group). The effect of treatment is normally quantified as a standardized mean difference (SMD). We describe procedures for computing unbiased estimates of the population SMD from sample data (e.g., group Ms and SDs), and provide guidance about a number of complications that may arise related to effect size computation. These complications include (a) incomplete data in research reports; (b) use of baseline data in computing SMDs and estimating the population standard deviation (σ); (c) combining effect size data from studies using different research designs; and (d) appropriate techniques for analysis of data from studies providing multiple estimates of the effect of interest (i.e., dependent effect sizes). Clinical or Methodological Significance of this article: Meta-analysis is a set of techniques for producing valid summaries of existing research. The initial computational step for meta-analyses of research on intervention outcomes involves computing an effect size quantifying the change attributable to the intervention. We discuss common issues in the computation of effect sizes and provide recommended procedures to address them.

  15. Biogeochemical Responses and Feedbacks to Climate Change: Synthetic Meta-Analyses Relevant to Earth System Models

    Energy Technology Data Exchange (ETDEWEB)

    van Gestel, Natasja; Jan van Groenigen, Kees; Osenberg, Craig; Dukes, Jeffrey; Dijkstra, Paul

    2018-03-20

    This project examined the sensitivity of carbon in land ecosystems to environmental change, focusing on carbon contained in soil, and the role of carbon-nitrogen interactions in regulating ecosystem carbon storage. The project used a combination of empirical measurements, mathematical models, and statistics to partition effects of climate change on soil into processes enhancing soil carbon and processes through which it decomposes. By synthesizing results from experiments around the world, the work provided novel insight on ecological controls and responses across broad spatial and temporal scales. The project developed new approaches in meta-analysis using principles of element mass balance and large datasets to derive metrics of ecosystem responses to environmental change. The project used meta-analysis to test how nutrients regulate responses of ecosystems to elevated CO2 and warming, in particular responses of nitrogen fixation, critical for regulating long-term C balance.

  16. An Introduction to Systematic Reviews and Meta-Analyses for Exotic Animal Practitioners

    NARCIS (Netherlands)

    Meursinge Reynders, Reint

    2017-01-01

    Developing and conducting systematic reviews and meta-analyses is a complex process that requires many judgments and the input from a wide variety of stakeholders. This article presents an introduction on how to develop, conduct, and report these research studies. Veterinary clinicians should seek

  17. Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer: Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses

    Science.gov (United States)

    Khankari, Nikhil K.; Shu, Xiao-Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I.; Easton, Douglas; Gruber, Stephen B.; Haiman, Christopher A.; Hunter, David J.; Chanock, Stephen J.; Pierce, Brandon L.; Zheng, Wei

    2016-01-01

    Background Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using height-associated genetic variants identified in a genome-wide association study (GWAS), to evaluate the association of adult height with these cancers. Methods and Findings A systematic review of prospective studies was conducted using the PubMed, Embase, and Web of Science databases. Using meta-analyses, results obtained from 62 studies were summarized for the association of a 10-cm increase in height with cancer risk. Mendelian randomization analyses were conducted using summary statistics obtained for 423 genetic variants identified from a recent GWAS of adult height and from a cancer genetics consortium study of multiple cancers that included 47,800 cases and 81,353 controls. For a 10-cm increase in height, the summary relative risks derived from the meta-analyses of prospective studies were 1.12 (95% CI 1.10, 1.15), 1.07 (95% CI 1.05, 1.10), and 1.06 (95% CI 1.02, 1.11) for colorectal, prostate, and lung cancers, respectively. Mendelian randomization analyses showed increased risks of colorectal (odds ratio [OR] = 1.58, 95% CI 1.14, 2.18) and lung cancer (OR = 1.10, 95% CI 1.00, 1.22) associated with each 10-cm increase in genetically predicted height. No association was observed for prostate cancer (OR = 1.03, 95% CI 0.92, 1.15). Our meta-analysis was limited to published studies. The sample size for the Mendelian randomization analysis of colorectal cancer was relatively small, thus affecting the precision of the point estimate. Conclusions Our study provides evidence for a potential causal association of adult height with the risk of colorectal and lung cancers and suggests that certain genetic factors and biological pathways affecting adult height may also affect the

  18. Techniques for Analysing Problems in Engineering Projects

    DEFF Research Database (Denmark)

    Thorsteinsson, Uffe

    1998-01-01

    Description of how CPM network can be used for analysing complex problems in engineering projects.......Description of how CPM network can be used for analysing complex problems in engineering projects....

  19. Methodologic quality of meta-analyses and systematic reviews on the Mediterranean diet and cardiovascular disease outcomes: a review.

    Science.gov (United States)

    Huedo-Medina, Tania B; Garcia, Marissa; Bihuniak, Jessica D; Kenny, Anne; Kerstetter, Jane

    2016-03-01

    Several systematic reviews/meta-analyses published within the past 10 y have examined the associations of Mediterranean-style diets (MedSDs) on cardiovascular disease (CVD) risk. However, these reviews have not been evaluated for satisfying contemporary methodologic quality standards. This study evaluated the quality of recent systematic reviews/meta-analyses on MedSD and CVD risk outcomes by using an established methodologic quality scale. The relation between review quality and impact per publication value of the journal in which the article had been published was also evaluated. To assess compliance with current standards, we applied a modified version of the Assessment of Multiple Systematic Reviews (AMSTARMedSD) quality scale to systematic reviews/meta-analyses retrieved from electronic databases that had met our selection criteria: 1) used systematic or meta-analytic procedures to review the literature, 2) examined MedSD trials, and 3) had MedSD interventions independently or combined with other interventions. Reviews completely satisfied from 8% to 75% of the AMSTARMedSD items (mean ± SD: 31.2% ± 19.4%), with those published in higher-impact journals having greater quality scores. At a minimum, 60% of the 24 reviews did not disclose full search details or apply appropriate statistical methods to combine study findings. Only 5 of the reviews included participant or study characteristics in their analyses, and none evaluated MedSD diet characteristics. These data suggest that current meta-analyses/systematic reviews evaluating the effect of MedSD on CVD risk do not fully comply with contemporary methodologic quality standards. As a result, there are more research questions to answer to enhance our understanding of how MedSD affects CVD risk or how these effects may be modified by the participant or MedSD characteristics. To clarify the associations between MedSD and CVD risk, future meta-analyses and systematic reviews should not only follow methodologic

  20. Reporting of conflicts of interests in meta-analyses of trials of pharmacological treatments

    NARCIS (Netherlands)

    Roseman, M.; Milette, K.; Bero, A.B.; Coyne, J.C.; Lexchin, J.; Turner, E.H.; Thombs, B.D.

    2011-01-01

    Abstract CONTEXT: Disclosure of conflicts of interest (COIs) from pharmaceutical industry study funding and author-industry financial relationships is sometimes recommended for randomized controlled trials (RCTs) published in biomedical journals. Authors of meta-analyses, however, are not required

  1. The more total cognitive load is reduced by cues, the better retention and transfer of multimedia learning: A meta-analysis and two meta-regression analyses.

    Science.gov (United States)

    Xie, Heping; Wang, Fuxing; Hao, Yanbin; Chen, Jiaxue; An, Jing; Wang, Yuxin; Liu, Huashan

    2017-01-01

    Cueing facilitates retention and transfer of multimedia learning. From the perspective of cognitive load theory (CLT), cueing has a positive effect on learning outcomes because of the reduction in total cognitive load and avoidance of cognitive overload. However, this has not been systematically evaluated. Moreover, what remains ambiguous is the direct relationship between the cue-related cognitive load and learning outcomes. A meta-analysis and two subsequent meta-regression analyses were conducted to explore these issues. Subjective total cognitive load (SCL) and scores on a retention test and transfer test were selected as dependent variables. Through a systematic literature search, 32 eligible articles encompassing 3,597 participants were included in the SCL-related meta-analysis. Among them, 25 articles containing 2,910 participants were included in the retention-related meta-analysis and the following retention-related meta-regression, while there were 29 articles containing 3,204 participants included in the transfer-related meta-analysis and the transfer-related meta-regression. The meta-analysis revealed a statistically significant cueing effect on subjective ratings of cognitive load (d = -0.11, 95% CI = [-0.19, -0.02], p < 0.05), retention performance (d = 0.27, 95% CI = [0.08, 0.46], p < 0.01), and transfer performance (d = 0.34, 95% CI = [0.12, 0.56], p < 0.01). The subsequent meta-regression analyses showed that dSCL for cueing significantly predicted dretention for cueing (β = -0.70, 95% CI = [-1.02, -0.38], p < 0.001), as well as dtransfer for cueing (β = -0.60, 95% CI = [-0.92, -0.28], p < 0.001). Thus in line with CLT, adding cues in multimedia materials can indeed reduce SCL and promote learning outcomes, and the more SCL is reduced by cues, the better retention and transfer of multimedia learning.

  2. On Conducting Construct Validity Meta-Analyses for the Rorschach: A Reply to Tibon Czopp and Zeligman (2016).

    Science.gov (United States)

    Mihura, Joni L; Meyer, Gregory J; Dumitrascu, Nicolae; Bombel, George

    2016-01-01

    We respond to Tibon Czopp and Zeligman's (2016) critique of our systematic reviews and meta-analyses of 65 Rorschach Comprehensive System (CS) variables published in Psychological Bulletin (2013). The authors endorsed our supportive findings but critiqued the same methodology when used for the 13 unsupported variables. Unfortunately, their commentary was based on significant misunderstandings of our meta-analytic method and results, such as thinking we used introspectively assessed criteria in classifying levels of support and reporting only a subset of our externally assessed criteria. We systematically address their arguments that our construct label and criterion variable choices were inaccurate and, therefore, meta-analytic validity for these 13 CS variables was artificially low. For example, the authors created new construct labels for these variables that they called "the customary CS interpretation," but did not describe their methodology nor provide evidence that their labels would result in better validity than ours. They cite studies they believe we should have included; we explain how these studies did not fit our inclusion criteria and that including them would have actually reduced the relevant CS variables' meta-analytic validity. Ultimately, criticisms alone cannot change meta-analytic support from negative to positive; Tibon Czopp and Zeligman would need to conduct their own construct validity meta-analyses.

  3. [Clinical research XXIII. From clinical judgment to meta-analyses].

    Science.gov (United States)

    Rivas-Ruiz, Rodolfo; Castelán-Martínez, Osvaldo D; Pérez-Rodríguez, Marcela; Palacios-Cruz, Lino; Noyola-Castillo, Maura E; Talavera, Juan O

    2014-01-01

    Systematic reviews (SR) are studies made in order to ask clinical questions based on original articles. Meta-analysis (MTA) is the mathematical analysis of SR. These analyses are divided in two groups, those which evaluate the measured results of quantitative variables (for example, the body mass index -BMI-) and those which evaluate qualitative variables (for example, if a patient is alive or dead, or if he is healing or not). Quantitative variables generally use the mean difference analysis and qualitative variables can be performed using several calculations: odds ratio (OR), relative risk (RR), absolute risk reduction (ARR) and hazard ratio (HR). These analyses are represented through forest plots which allow the evaluation of each individual study, as well as the heterogeneity between studies and the overall effect of the intervention. These analyses are mainly based on Student's t test and chi-squared. To take appropriate decisions based on the MTA, it is important to understand the characteristics of statistical methods in order to avoid misinterpretations.

  4. Reporting of Conflicts of Interest in Meta-analyses of Trials of Pharmacological Treatments

    NARCIS (Netherlands)

    Roseman, Michelle; Milette, Katherine; Bero, Lisa A.; Coyne, James C.; Lexchin, Joel; Turner, Erick H.; Thombs, Brett D.

    2011-01-01

    Context Disclosure of conflicts of interest (COIs) from pharmaceutical industry study funding and author-industry financial relationships is sometimes recommended for randomized controlled trials (RCTs) published in biomedical journals. Authors of meta-analyses, however, are not required to report

  5. Disagreements in meta-analyses using outcomes measured on continuous or rating scales: observer agreement study

    DEFF Research Database (Denmark)

    Tendal, Britta; Higgins, Julian P T; Jüni, Peter

    2009-01-01

    difference (SMD), the protocols for the reviews and the trial reports (n=45) were retrieved. DATA EXTRACTION: Five experienced methodologists and five PhD students independently extracted data from the trial reports for calculation of the first SMD result in each review. The observers did not have access...... to the reviews but to the protocols, where the relevant outcome was highlighted. The agreement was analysed at both trial and meta-analysis level, pairing the observers in all possible ways (45 pairs, yielding 2025 pairs of trials and 450 pairs of meta-analyses). Agreement was defined as SMDs that differed less...... than 0.1 in their point estimates or confidence intervals. RESULTS: The agreement was 53% at trial level and 31% at meta-analysis level. Including all pairs, the median disagreement was SMD=0.22 (interquartile range 0.07-0.61). The experts agreed somewhat more than the PhD students at trial level (61...

  6. The Limited Informativeness of Meta-Analyses of Media Effects.

    Science.gov (United States)

    Valkenburg, Patti M

    2015-09-01

    In this issue of Perspectives on Psychological Science, Christopher Ferguson reports on a meta-analysis examining the relationship between children's video game use and several outcome variables, including aggression and attention deficit symptoms (Ferguson, 2015, this issue). In this commentary, I compare Ferguson's nonsignificant effects sizes with earlier meta-analyses on the same topics that yielded larger, significant effect sizes. I argue that Ferguson's choice for partial effects sizes is unjustified on both methodological and theoretical grounds. I then plead for a more constructive debate on the effects of violent video games on children and adolescents. Until now, this debate has been dominated by two camps with diametrically opposed views on the effects of violent media on children. However, even the earliest media effects studies tell us that children can react quite differently to the same media content. Thus, if researchers truly want to understand how media affect children, rather than fight for the presence or absence of effects, they need to adopt a perspective that takes differential susceptibility to media effects more seriously. © The Author(s) 2015.

  7. Meta-Analyst: software for meta-analysis of binary, continuous and diagnostic data

    Directory of Open Access Journals (Sweden)

    Schmid Christopher H

    2009-12-01

    Full Text Available Abstract Background Meta-analysis is increasingly used as a key source of evidence synthesis to inform clinical practice. The theory and statistical foundations of meta-analysis continually evolve, providing solutions to many new and challenging problems. In practice, most meta-analyses are performed in general statistical packages or dedicated meta-analysis programs. Results Herein, we introduce Meta-Analyst, a novel, powerful, intuitive, and free meta-analysis program for the meta-analysis of a variety of problems. Meta-Analyst is implemented in C# atop of the Microsoft .NET framework, and features a graphical user interface. The software performs several meta-analysis and meta-regression models for binary and continuous outcomes, as well as analyses for diagnostic and prognostic test studies in the frequentist and Bayesian frameworks. Moreover, Meta-Analyst includes a flexible tool to edit and customize generated meta-analysis graphs (e.g., forest plots and provides output in many formats (images, Adobe PDF, Microsoft Word-ready RTF. The software architecture employed allows for rapid changes to be made to either the Graphical User Interface (GUI or to the analytic modules. We verified the numerical precision of Meta-Analyst by comparing its output with that from standard meta-analysis routines in Stata over a large database of 11,803 meta-analyses of binary outcome data, and 6,881 meta-analyses of continuous outcome data from the Cochrane Library of Systematic Reviews. Results from analyses of diagnostic and prognostic test studies have been verified in a limited number of meta-analyses versus MetaDisc and MetaTest. Bayesian statistical analyses use the OpenBUGS calculation engine (and are thus as accurate as the standalone OpenBUGS software. Conclusion We have developed and validated a new program for conducting meta-analyses that combines the advantages of existing software for this task.

  8. Uptake of systematic reviews and meta-analyses based on individual participant data in clinical practice guidelines: descriptive study

    NARCIS (Netherlands)

    Vale, C.L.; Rydzewska, L.H.; Rovers, M.M.; Emberson, J.R.; Gueyffier, F.; Stewart, L.A.

    2015-01-01

    OBJECTIVE: To establish the extent to which systematic reviews and meta-analyses of individual participant data (IPD) are being used to inform the recommendations included in published clinical guidelines. DESIGN: Descriptive study. SETTING: Database maintained by the Cochrane IPD Meta-analysis

  9. New Blood Pressure-Associated Loci Identified in Meta-Analyses of 475 000 Individuals

    DEFF Research Database (Denmark)

    Kraja, Aldi T.; Cook, James P.; Warren, Helen R.

    2017-01-01

    Background - Genome-wide association studies have recently identified >400 loci that harbor DNA sequence variants that influence blood pressure (BP). Our earlier studies identified and validated 56 single nucleotide variants (SNVs) associated with BP from meta-analyses of exome chip genotype data...

  10. Cooper's Taxonomy of Literature Reviews Applied to Meta-Analyses in Educational Achievement.

    Science.gov (United States)

    Sipe, Theresa Ann; Stallings, William M.

    H. M. Cooper (1988) has developed a taxonomy that classified literature reviews based on six characteristics: (1) focus of attention; (2) goal of the synthesis; (3) perspective on the literature; (4) coverage of the literature; (5) organization of the perspective; and (6) intended audience. One hundred and three meta-analyses identified from the…

  11. Efficacy of pharmacotherapy and psychotherapy for adult psychiatric disorders: a systematic overview of meta-analyses.

    Science.gov (United States)

    Huhn, Maximilian; Tardy, Magdolna; Spineli, Loukia Maria; Kissling, Werner; Förstl, Hans; Pitschel-Walz, Gabriele; Leucht, Claudia; Samara, Myrto; Dold, Markus; Davis, John M; Leucht, Stefan

    2014-06-01

    There is debate about the effectiveness of psychiatric treatments and whether pharmacotherapy or psychotherapy should be primarily used. To perform a systematic overview on the efficacy of pharmacotherapies and psychotherapies for major psychiatric disorders and to compare the quality of pharmacotherapy and psychotherapy trials. We searched MEDLINE, EMBASE, PsycINFO, and the Cochrane Library (April 2012, with no time or language limit) for systematic reviews on pharmacotherapy or psychotherapy vs placebo, pharmacotherapy vs psychotherapy, and their combination vs either modality alone. Two reviewers independently selected the meta-analyses and extracted efficacy effect sizes. We assessed the quality of the individual trials included in the pharmacotherapy and psychotherapy meta-analyses with the Cochrane risk of bias tool. The search yielded 45,233 results. We included 61 meta-analyses on 21 psychiatric disorders, which contained 852 individual trials and 137,126 participants. The mean effect size of the meta-analyses was medium (mean, 0.50; 95% CI, 0.41-0.59). Effect sizes of psychotherapies vs placebo tended to be higher than those of medication, but direct comparisons, albeit usually based on few trials, did not reveal consistent differences. Individual pharmacotherapy trials were more likely to have large sample sizes, blinding, control groups, and intention-to-treat analyses. In contrast, psychotherapy trials had lower dropout rates and provided follow-up data. In psychotherapy studies, wait-list designs showed larger effects than did comparisons with placebo. Many pharmacotherapies and psychotherapies are effective, but there is a lot of room for improvement. Because of the multiple differences in the methods used in pharmacotherapy and psychotherapy trials, indirect comparisons of their effect sizes compared with placebo or no treatment are problematic. Well-designed direct comparisons, which are scarce, need public funding. Because patients often benefit

  12. Quality of meta-analyses in major leading gastroenterology and hepatology journals: A systematic review.

    Science.gov (United States)

    Liu, Pengfei; Qiu, Yuanyu; Qian, Yuting; Chen, Xiao; Wang, Yiran; Cui, Jin; Zhai, Xiao

    2017-01-01

    To appraise the current reporting methodological quality of meta-analyses in five leading gastroenterology and hepatology journals, and to identify the variables associated with the reporting quality. We systematically searched the literature of meta-analyses in Gastroenterology, Gut, Hepatology, Journal of Hepatology (J HEPATOL) and American Journal of Gastroenterology (AM J GASTROENTEROL) from 2006 to 2008 and from 2012 to 2014. Characteristics were extracted based on the PRISMA statement and the AMSTAR tool. Country, number of patients, funding source were also revealed and descriptively reported. A total of 127 meta-analyses were enrolled in this study and were compared among journals, study years, and other characters. Compliances with the PRISMA statement and the AMSTAR checklist were 20.8 ± 4.2 out of a maximum of 27 and 7.6 ± 2.4 out of a maximum of 11, respectively. Some domains were poorly reported including describing a protocol and/or registration (item 5, 0.0%), describing methods, and giving results of additional analyses (item 16, 45.7% and item 23, 48.0%) for PRISMA and duplicating study selection and data extraction (item 2, 53.5%), and providing a list of included and excluded studies (item 5, 14.2%) for AMSTAR. Publication in recent years showed a significantly better methodological quality than those published in previous years. This study shows that methodological reporting quality of MAs in the major gastroenterology and hepatology journals has improved in recent years after the publication of the developed PRISMA statement, and it can be further improved. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  13. Sex Differences in Objective and Projective Dependency Tests: A Meta-Analytic Review.

    Science.gov (United States)

    Bornstein, Robert F.

    1995-01-01

    A meta-analysis of 97 studies published since 1950 that assessed sex differences in scores on objective and projective dependency tests indicated that women consistently obtained higher dependency scores on objective tests, and men obtained higher scores on projective tests. Findings are discussed in terms of sex role socialization. (SLD)

  14. Variables associated with achievement in higher education: A systematic review of meta-analyses.

    Science.gov (United States)

    Schneider, Michael; Preckel, Franzis

    2017-06-01

    The last 2 decades witnessed a surge in empirical studies on the variables associated with achievement in higher education. A number of meta-analyses synthesized these findings. In our systematic literature review, we included 38 meta-analyses investigating 105 correlates of achievement, based on 3,330 effect sizes from almost 2 million students. We provide a list of the 105 variables, ordered by the effect size, and summary statistics for central research topics. The results highlight the close relation between social interaction in courses and achievement. Achievement is also strongly associated with the stimulation of meaningful learning by presenting information in a clear way, relating it to the students, and using conceptually demanding learning tasks. Instruction and communication technology has comparably weak effect sizes, which did not increase over time. Strong moderator effects are found for almost all instructional methods, indicating that how a method is implemented in detail strongly affects achievement. Teachers with high-achieving students invest time and effort in designing the microstructure of their courses, establish clear learning goals, and employ feedback practices. This emphasizes the importance of teacher training in higher education. Students with high achievement are characterized by high self-efficacy, high prior achievement and intelligence, conscientiousness, and the goal-directed use of learning strategies. Barring the paucity of controlled experiments and the lack of meta-analyses on recent educational innovations, the variables associated with achievement in higher education are generally well investigated and well understood. By using these findings, teachers, university administrators, and policymakers can increase the effectivity of higher education. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  15. The Reporting Quality of Systematic Reviews and Meta-Analyses in Industrial and Organizational Psychology: A Systematic Review.

    Science.gov (United States)

    Schalken, Naomi; Rietbergen, Charlotte

    2017-01-01

    Objective: The goal of this systematic review was to examine the reporting quality of the method section of quantitative systematic reviews and meta-analyses from 2009 to 2016 in the field of industrial and organizational psychology with the help of the Meta-Analysis Reporting Standards (MARS), and to update previous research, such as the study of Aytug et al. (2012) and Dieckmann et al. (2009). Methods: A systematic search for quantitative systematic reviews and meta-analyses was conducted in the top 10 journals in the field of industrial and organizational psychology between January 2009 and April 2016. Data were extracted on study characteristics and items of the method section of MARS. A cross-classified multilevel model was analyzed, to test whether publication year and journal impact factor (JIF) were associated with the reporting quality scores of articles. Results: Compliance with MARS in the method section was generally inadequate in the random sample of 120 articles. Variation existed in the reporting of items. There were no significant effects of publication year and journal impact factor (JIF) on the reporting quality scores of articles. Conclusions: The reporting quality in the method section of systematic reviews and meta-analyses was still insufficient, therefore we recommend researchers to improve the reporting in their articles by using reporting standards like MARS.

  16. Endorsement of PRISMA statement and quality of systematic reviews and meta-analyses published in nursing journals: a cross-sectional study.

    Science.gov (United States)

    Tam, Wilson W S; Lo, Kenneth K H; Khalechelvam, Parames

    2017-02-07

    Systematic reviews (SRs) often poorly report key information, thereby diminishing their usefulness. Previous studies evaluated published SRs and determined that they failed to meet explicit criteria or characteristics. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was recommended as a reporting guideline for SR and meta-analysis (MA), but previous studies showed that adherence to the statement was not high for SRs published in different medical fields. Thus, the aims of this study are twofold: (1) to investigate the number of nursing journals that have required or recommended the use of the PRISMA statement for reporting SR, and (2) to examine the adherence of SRs and/or meta-analyses to the PRISMA statement published in nursing journals. A cross-sectional study. Nursing journals listed in the ISI journal citation report were divided into 2 groups based on the recommendation of PRISMA statement in their 'Instruction for Authors'. SRs and meta-analyses published in 2014 were searched in 3 databases. 37 SRs and meta-analyses were randomly selected in each group. The adherence of each item to the PRISMA was examined and summarised using descriptive statistics. The quality of the SRs was assessed by Assessing the Methodological Quality of Systematic Reviews. The differences between the 2 groups were compared using the Mann-Whitney U test. Out of 107 nursing journals, 30 (28.0%) recommended or required authors to follow the PRISMA statement when they submit SRs or meta-analyses. The median rates of adherence to the PRISMA statement for reviews published in journals with and without PRISMA endorsement were 64.9% (IQR: 17.6-92.3%) and 73.0% (IQR: 59.5-94.6%), respectively. No significant difference was observed in any of the items between the 2 groups. The median adherence of SRs and meta-analyses in nursing journals to PRISMA is low at 64.9% and 73.0%, respectively. Nonetheless, the adherence level of nursing journals to the

  17. Endorsement of PRISMA statement and quality of systematic reviews and meta-analyses published in nursing journals: a cross-sectional study

    Science.gov (United States)

    Tam, Wilson W S; Lo, Kenneth K H; Khalechelvam, Parames

    2017-01-01

    Objective Systematic reviews (SRs) often poorly report key information, thereby diminishing their usefulness. Previous studies evaluated published SRs and determined that they failed to meet explicit criteria or characteristics. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was recommended as a reporting guideline for SR and meta-analysis (MA), but previous studies showed that adherence to the statement was not high for SRs published in different medical fields. Thus, the aims of this study are twofold: (1) to investigate the number of nursing journals that have required or recommended the use of the PRISMA statement for reporting SR, and (2) to examine the adherence of SRs and/or meta-analyses to the PRISMA statement published in nursing journals. Design A cross-sectional study. Methods Nursing journals listed in the ISI journal citation report were divided into 2 groups based on the recommendation of PRISMA statement in their ‘Instruction for Authors’. SRs and meta-analyses published in 2014 were searched in 3 databases. 37 SRs and meta-analyses were randomly selected in each group. The adherence of each item to the PRISMA was examined and summarised using descriptive statistics. The quality of the SRs was assessed by Assessing the Methodological Quality of Systematic Reviews. The differences between the 2 groups were compared using the Mann-Whitney U test. Results Out of 107 nursing journals, 30 (28.0%) recommended or required authors to follow the PRISMA statement when they submit SRs or meta-analyses. The median rates of adherence to the PRISMA statement for reviews published in journals with and without PRISMA endorsement were 64.9% (IQR: 17.6–92.3%) and 73.0% (IQR: 59.5–94.6%), respectively. No significant difference was observed in any of the items between the 2 groups. Conclusions The median adherence of SRs and meta-analyses in nursing journals to PRISMA is low at 64.9% and 73.0%, respectively

  18. Meta-Analyses of the Associations of Respiratory Health Effectswith Dampness and Mold in Homes

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J.; Lei-Gomez, Quanhong; Mendell, Mark J.

    2006-01-01

    The Institute of Medicine (IOM) of the National Academy of Sciences recently completed a critical review of the scientific literature pertaining to the association of indoor dampness and mold contamination with adverse health effects. In this paper, we report the results of quantitative meta-analysis of the studies reviewed in the IOM report. We developed point estimates and confidence intervals (CIs) to summarize the association of several respiratory and asthma-related health outcomes with the presence of dampness and mold in homes. The odds ratios and confidence intervals from the original studies were transformed to the log scale and random effect models were applied to the log odds ratios and their variance. Models were constructed both accounting for the correlation between multiple results within the studies analyzed and ignoring such potential correlation. Central estimates of ORs for the health outcomes ranged from 1.32 to 2.10, with most central estimates between 1.3 and 1.8. Confidence intervals (95%) excluded unity except in two of 28 instances, and in most cases the lower bound of the CI exceeded 1.2. In general, the two meta-analysis methods produced similar estimates for ORs and CIs. Based on the results of the meta-analyses, building dampness and mold are associated with approximately 30% to 80% increases in a variety of respiratory and asthma-related health outcomes. The results of these meta-analyses reinforce the IOM's recommendation that actions be taken to prevent and reduce building dampness problems.

  19. Systematic assessment of environmental risk factors for bipolar disorder: an umbrella review of systematic reviews and meta-analyses.

    Science.gov (United States)

    Bortolato, Beatrice; Köhler, Cristiano A; Evangelou, Evangelos; León-Caballero, Jordi; Solmi, Marco; Stubbs, Brendon; Belbasis, Lazaros; Pacchiarotti, Isabella; Kessing, Lars V; Berk, Michael; Vieta, Eduard; Carvalho, André F

    2017-03-01

    The pathophysiology of bipolar disorder is likely to involve both genetic and environmental risk factors. In our study, we aimed to perform a systematic search of environmental risk factors for BD. In addition, we assessed possible hints of bias in this literature, and identified risk factors supported by high epidemiological credibility. We searched the Pubmed/MEDLINE, EMBASE and PsycInfo databases up to 7 October 2016 to identify systematic reviews and meta-analyses of observational studies that assessed associations between putative environmental risk factors and BD. For each meta-analysis, we estimated its summary effect size by means of both random- and fixed-effects models, 95% confidence intervals (CIs), the 95% prediction interval, and heterogeneity. Evidence of small-study effects and excess of significance bias was also assessed. Sixteen publications met the inclusion criteria (seven meta-analyses and nine qualitative systematic reviews). Fifty-one unique environmental risk factors for BD were evaluated. Six meta-analyses investigated associations with a risk factor for BD. Only irritable bowel syndrome (IBS) emerged as a risk factor for BD supported by convincing evidence (k=6; odds ratio [OR]=2.48; 95% CI=2.35-2.61; P<.001), and childhood adversity was supported by highly suggestive evidence. Asthma and obesity were risk factors for BD supported by suggestive evidence, and seropositivity to Toxoplasma gondii and a history of head injury were supported by weak evidence. Notwithstanding that several environmental risk factors for BD were identified, few meta-analyses of observational studies were available. Therefore, further well-designed and adequately powered studies are necessary to map the environmental risk factors for BD. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Teaching meta-analysis using MetaLight

    Directory of Open Access Journals (Sweden)

    Thomas James

    2012-10-01

    Full Text Available Abstract Background Meta-analysis is a statistical method for combining the results of primary studies. It is often used in systematic reviews and is increasingly a method and topic that appears in student dissertations. MetaLight is a freely available software application that runs simple meta-analyses and contains specific functionality to facilitate the teaching and learning of meta-analysis. While there are many courses and resources for meta-analysis available and numerous software applications to run meta-analyses, there are few pieces of software which are aimed specifically at helping those teaching and learning meta-analysis. Valuable teaching time can be spent learning the mechanics of a new software application, rather than on the principles and practices of meta-analysis. Findings We discuss ways in which the MetaLight tool can be used to present some of the main issues involved in undertaking and interpreting a meta-analysis. Conclusions While there are many software tools available for conducting meta-analysis, in the context of a teaching programme such software can require expenditure both in terms of money and in terms of the time it takes to learn how to use it. MetaLight was developed specifically as a tool to facilitate the teaching and learning of meta-analysis and we have presented here some of the ways it might be used in a training situation.

  1. Preventive intervention possibilities in radiotherapy- and chemotherapy-induced oral mucositis : Results of meta-analyses

    NARCIS (Netherlands)

    Stokman, M A; Spijkervet, F K L; Boezen, H M; Schouten, J.P.; Roodenburg, J L N; de Vries, E. G. E.

    The aim of these meta-analyses was to evaluate the effectiveness of interventions for the prevention of oral mucositis in cancer patients treated with head and neck radiotherapy and/or chemotherapy, with a focus on randomized clinical trials. A literature search was performed for reports of

  2. Effectiveness and cost-effectiveness of ehealth interventions in somatic diseases: a systematic review of systematic reviews and meta-analyses.

    Science.gov (United States)

    Elbert, Niels J; van Os-Medendorp, Harmieke; van Renselaar, Wilco; Ekeland, Anne G; Hakkaart-van Roijen, Leona; Raat, Hein; Nijsten, Tamar E C; Pasmans, Suzanne G M A

    2014-04-16

    eHealth potentially enhances quality of care and may reduce health care costs. However, a review of systematic reviews published in 2010 concluded that high-quality evidence on the benefits of eHealth interventions was still lacking. We conducted a systematic review of systematic reviews and meta-analyses on the effectiveness/cost-effectiveness of eHealth interventions in patients with somatic diseases to analyze whether, and to what possible extent, the outcome of recent research supports or differs from previous conclusions. Literature searches were performed in PubMed, EMBASE, The Cochrane Library, and Scopus for systematic reviews and meta-analyses on eHealth interventions published between August 2009 and December 2012. Articles were screened for relevance based on preset inclusion and exclusion criteria. Citations of residual articles were screened for additional literature. Included papers were critically appraised using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement before data were extracted. Based on conclusions drawn by the authors of the included articles, reviews and meta-analyses were divided into 1 of 3 groups: suitable, promising, or limited evidence on effectiveness/cost-effectiveness. Cases of uncertainty were resolved by consensus discussion. Effect sizes were extracted from papers that included a meta-analysis. To compare our results with previous findings, a trend analysis was performed. Our literature searches yielded 31 eligible reviews, of which 20 (65%) reported on costs. Seven papers (23%) concluded that eHealth is effective/cost-effective, 13 (42%) underlined that evidence is promising, and others found limited or inconsistent proof. Methodological quality of the included reviews and meta-analyses was generally considered high. Trend analysis showed a considerable accumulation of literature on eHealth. However, a similar percentage of papers concluded that eHealth is effective/cost-effective or

  3. The Influence of Study-Level Inference Models and Study Set Size on Coordinate-Based fMRI Meta-Analyses

    Directory of Open Access Journals (Sweden)

    Han Bossier

    2018-01-01

    Full Text Available Given the increasing amount of neuroimaging studies, there is a growing need to summarize published results. Coordinate-based meta-analyses use the locations of statistically significant local maxima with possibly the associated effect sizes to aggregate studies. In this paper, we investigate the influence of key characteristics of a coordinate-based meta-analysis on (1 the balance between false and true positives and (2 the activation reliability of the outcome from a coordinate-based meta-analysis. More particularly, we consider the influence of the chosen group level model at the study level [fixed effects, ordinary least squares (OLS, or mixed effects models], the type of coordinate-based meta-analysis [Activation Likelihood Estimation (ALE that only uses peak locations, fixed effects, and random effects meta-analysis that take into account both peak location and height] and the amount of studies included in the analysis (from 10 to 35. To do this, we apply a resampling scheme on a large dataset (N = 1,400 to create a test condition and compare this with an independent evaluation condition. The test condition corresponds to subsampling participants into studies and combine these using meta-analyses. The evaluation condition corresponds to a high-powered group analysis. We observe the best performance when using mixed effects models in individual studies combined with a random effects meta-analysis. Moreover the performance increases with the number of studies included in the meta-analysis. When peak height is not taken into consideration, we show that the popular ALE procedure is a good alternative in terms of the balance between type I and II errors. However, it requires more studies compared to other procedures in terms of activation reliability. Finally, we discuss the differences, interpretations, and limitations of our results.

  4. Meta-analyses and Forest plots using a microsoft excel spreadsheet: step-by-step guide focusing on descriptive data analysis.

    Science.gov (United States)

    Neyeloff, Jeruza L; Fuchs, Sandra C; Moreira, Leila B

    2012-01-20

    Meta-analyses are necessary to synthesize data obtained from primary research, and in many situations reviews of observational studies are the only available alternative. General purpose statistical packages can meta-analyze data, but usually require external macros or coding. Commercial specialist software is available, but may be expensive and focused in a particular type of primary data. Most available softwares have limitations in dealing with descriptive data, and the graphical display of summary statistics such as incidence and prevalence is unsatisfactory. Analyses can be conducted using Microsoft Excel, but there was no previous guide available. We constructed a step-by-step guide to perform a meta-analysis in a Microsoft Excel spreadsheet, using either fixed-effect or random-effects models. We have also developed a second spreadsheet capable of producing customized forest plots. It is possible to conduct a meta-analysis using only Microsoft Excel. More important, to our knowledge this is the first description of a method for producing a statistically adequate but graphically appealing forest plot summarizing descriptive data, using widely available software.

  5. Meta-analyses and Forest plots using a microsoft excel spreadsheet: step-by-step guide focusing on descriptive data analysis

    Directory of Open Access Journals (Sweden)

    Neyeloff Jeruza L

    2012-01-01

    Full Text Available Abstract Background Meta-analyses are necessary to synthesize data obtained from primary research, and in many situations reviews of observational studies are the only available alternative. General purpose statistical packages can meta-analyze data, but usually require external macros or coding. Commercial specialist software is available, but may be expensive and focused in a particular type of primary data. Most available softwares have limitations in dealing with descriptive data, and the graphical display of summary statistics such as incidence and prevalence is unsatisfactory. Analyses can be conducted using Microsoft Excel, but there was no previous guide available. Findings We constructed a step-by-step guide to perform a meta-analysis in a Microsoft Excel spreadsheet, using either fixed-effect or random-effects models. We have also developed a second spreadsheet capable of producing customized forest plots. Conclusions It is possible to conduct a meta-analysis using only Microsoft Excel. More important, to our knowledge this is the first description of a method for producing a statistically adequate but graphically appealing forest plot summarizing descriptive data, using widely available software.

  6. The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration

    DEFF Research Database (Denmark)

    Liberati, Alessandro; Altman, Douglas G; Tetzlaff, Jennifer

    2009-01-01

    Systematic reviews and meta-analyses are essential to summarize evidence relating to efficacy and safety of health care interventions accurately and reliably. The clarity and transparency of these reports, however, is not optimal. Poor reporting of systematic reviews diminishes their value...... to clinicians, policy makers, and other users. Since the development of the QUOROM (QUality Of Reporting Of Meta-analysis) Statement--a reporting guideline published in 1999--there have been several conceptual, methodological, and practical advances regarding the conduct and reporting of systematic reviews...... and meta-analyses. Also, reviews of published systematic reviews have found that key information about these studies is often poorly reported. Realizing these issues, an international group that included experienced authors and methodologists developed PRISMA (Preferred Reporting Items for Systematic...

  7. The Evaluation of Bivariate Mixed Models in Meta-analyses of Diagnostic Accuracy Studies with SAS, Stata and R.

    Science.gov (United States)

    Vogelgesang, Felicitas; Schlattmann, Peter; Dewey, Marc

    2018-05-01

    Meta-analyses require a thoroughly planned procedure to obtain unbiased overall estimates. From a statistical point of view not only model selection but also model implementation in the software affects the results. The present simulation study investigates the accuracy of different implementations of general and generalized bivariate mixed models in SAS (using proc mixed, proc glimmix and proc nlmixed), Stata (using gllamm, xtmelogit and midas) and R (using reitsma from package mada and glmer from package lme4). Both models incorporate the relationship between sensitivity and specificity - the two outcomes of interest in meta-analyses of diagnostic accuracy studies - utilizing random effects. Model performance is compared in nine meta-analytic scenarios reflecting the combination of three sizes for meta-analyses (89, 30 and 10 studies) with three pairs of sensitivity/specificity values (97%/87%; 85%/75%; 90%/93%). The evaluation of accuracy in terms of bias, standard error and mean squared error reveals that all implementations of the generalized bivariate model calculate sensitivity and specificity estimates with deviations less than two percentage points. proc mixed which together with reitsma implements the general bivariate mixed model proposed by Reitsma rather shows convergence problems. The random effect parameters are in general underestimated. This study shows that flexibility and simplicity of model specification together with convergence robustness should influence implementation recommendations, as the accuracy in terms of bias was acceptable in all implementations using the generalized approach. Schattauer GmbH.

  8. An umbrella review of meta-analyses of interventions to improve maternal outcomes for teen mothers.

    Science.gov (United States)

    SmithBattle, Lee; Loman, Deborah G; Chantamit-O-Pas, Chutima; Schneider, Joanne Kraenzle

    2017-08-01

    The purpose of this study was to perform an umbrella review of meta-analyses of intervention studies designed to improve outcomes of pregnant or parenting teenagers. An extensive search retrieved nine reports which provided 21 meta-analyses analyses. Data were extracted by two reviewers. Methodological quality was assessed using the AMSTAR Instrument. Most effect sizes were small but high quality studies showed significant outcomes for reduced low birth weight (RR = 0.60), repeat pregnancies/births (OR = 0.47-0.62), maternal education (OR = 1.21-1.83), and maternal employment (OR = 1.26). Several parenting outcomes (parent-child teaching interaction post-intervention [SMD = -0.91] and at follow-up [SMD = -1.07], and parent-child relationship post-intervention [SMD = -0.71] and at follow-up [SMD = -0.90]) were significant, but sample sizes were very small. Many reports did not include moderator analyses. Behavioral interventions offer limited resources and occur too late to mitigate the educational and social disparities that precede teen pregnancy. Future intervention research and policies that redress the social determinants of early childbearing are recommended. Copyright © 2017 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  9. Individual patient data meta-analyses in head and neck carcinoma: what have we learnt?

    International Nuclear Information System (INIS)

    Pignon, J.P.; Baujat, B.; Bourhis, J.

    2005-01-01

    Carcinoma of the upper aero-digestive tract (oral cavity, oropharynx, hypopharynx, nasopharynx, larynx) are frequent tumors for which surgery and/or radiotherapy are the main therapeutic agents. The main results of meta-analyses based on the collection of individual patients data are reported: 1) The meta-analysis on chemotherapy, regrouping data of nearly 11,000 patients issued from 63 randomized trials showed an absolute benefit of 4% at five years in overall survival, in favor of chemotherapy (P < 0.0001). Most of the benefit was seen with concomitant radio-chemotherapy, however with a relatively large heterogeneity in this subgroup of trials. An update of this meta-analysis was performed including 24 additional trials, which confirmed the magnitude of the benefit due to concomitant chemotherapy (8% at 5 years). 2) The meta-analysis on larynx preservation, using induction chemotherapy in larynx and hypopharynx carcinomas. No significant difference was seen between the control arm with total laryngectomy and the larynx preservation approach. 3) The meta-analysis on chemotherapy in nasopharynx carcinomas, from the data of 11 randomized trials including 2722 patients, and comparing the radiotherapy to radio-chemotherapy (1979-2001). The results showed an absolute benefit of 6% at five years in overall survival, in favor of chemotherapy (P < 0.0001). Most of the benefit was seen with concomitant radio-chemotherapy. 4) Finally, a meta-analysis on altered fractionated RT, compared to conventional RT in 15 randomized trials regrouping 6515 patients. The results showed a small but significant improvement in favor of altered fractionated RT for overall survival and local control with an absolute benefit at five years of 3 and 6%, respectively. (author)

  10. Adjunctive Nutraceuticals for Depression: A Systematic Review and Meta-Analyses.

    Science.gov (United States)

    Sarris, Jerome; Murphy, Jenifer; Mischoulon, David; Papakostas, George I; Fava, Maurizio; Berk, Michael; Ng, Chee H

    2016-06-01

    There is burgeoning interest in augmentation strategies for improving inadequate response to antidepressants. The adjunctive use of standardized pharmaceutical-grade nutrients, known as nutraceuticals, has the potential to modulate several neurochemical pathways implicated in depression. While many studies have been conducted in this area, to date no specialized systematic review (or meta-analysis) has been conducted. A systematic search of PubMed, CINAHL, Cochrane Library, and Web of Science was conducted up to December 2015 for clinical trials using adjunctive nutrients for depression. Where sufficient data were available, a random-effects model analyzed the standard mean difference between treatment and placebo in the change from baseline to endpoint, combining the effect size data. Funnel plot and heterogeneity analyses were also performed. Primarily positive results were found for replicated studies testing S-adenosylmethionine (SAMe), methylfolate, omega-3 (primarily EPA or ethyl-EPA), and vitamin D, with positive isolated studies for creatine, folinic acid, and an amino acid combination. Mixed results were found for zinc, folic acid, vitamin C, and tryptophan, with nonsignificant results for inositol. No major adverse effects were noted in the studies (aside from minor digestive disturbance). A meta-analysis of adjunctive omega-3 versus placebo revealed a significant and moderate to strong effect in favor of omega-3. Conversely, a meta-analysis of folic acid revealed a nonsignificant difference from placebo. Marked study heterogeneity was found in a Higgins test for both omega-3 and folic acid studies; funnel plots also revealed asymmetry (reflecting potential study bias). Current evidence supports adjunctive use of SAMe, methylfolate, omega-3, and vitamin D with antidepressants to reduce depressive symptoms.

  11. Meta-Analyses of Seven of NIDA’s Principles of Drug Addiction Treatment

    Science.gov (United States)

    Pearson, Frank S.; Prendergast, Michael L.; Podus, Deborah; Vazan, Peter; Greenwell, Lisa; Hamilton, Zachary

    2011-01-01

    Seven of the 13 Principles of Drug Addiction Treatment disseminated by the National Institute on Drug Abuse (NIDA) were meta-analyzed as part of the Evidence-based Principles of Treatment (EPT) project. By averaging outcomes over the diverse programs included in EPT, we found that five of the NIDA principles examined are supported: matching treatment to the client’s needs; attending to the multiple needs of clients; behavioral counseling interventions; treatment plan reassessment; and counseling to reduce risk of HIV. Two of the NIDA principles are not supported: remaining in treatment for an adequate period of time and frequency of testing for drug use. These weak effects could be the result of the principles being stated too generally to apply to the diverse interventions and programs that exist or of unmeasured moderator variables being confounded with the moderators that measured the principles. Meta-analysis should be a standard tool for developing principles of effective treatment for substance use disorders. PMID:22119178

  12. The prevalence of child maltreatment across the globe: Review of a series of meta-analyses.

    NARCIS (Netherlands)

    Stoltenborgh, M.; Bakermans-Kranenburg, M.J.; Alink, L.R.A.; van IJzendoorn, M.H.

    2015-01-01

    In this review, we combine and compare the results of a series of meta-analyses on the prevalence of child sexual, physical and emotional abuse and physical and emotional neglect, including 244 publications and 551 prevalence rates for the various types of maltreatment. Child maltreatment research

  13. Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes.

    Science.gov (United States)

    Poole, Robin; Kennedy, Oliver J; Roderick, Paul; Fallowfield, Jonathan A; Hayes, Peter C; Parkes, Julie

    2017-11-22

    Objectives  To evaluate the existing evidence for associations between coffee consumption and multiple health outcomes. Design  Umbrella review of the evidence across meta-analyses of observational and interventional studies of coffee consumption and any health outcome. Data sources  PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, and screening of references. Eligibility criteria for selecting studies  Meta-analyses of both observational and interventional studies that examined the associations between coffee consumption and any health outcome in any adult population in all countries and all settings. Studies of genetic polymorphisms for coffee metabolism were excluded. Results  The umbrella review identified 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with nine unique outcomes. Coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures including high versus low, any versus none, and one extra cup a day. There was evidence of a non-linear association between consumption and some outcomes, with summary estimates indicating largest relative risk reduction at intakes of three to four cups a day versus none, including all cause mortality (relative risk 0.83 (95% confidence interval 0.79 to 0.88), cardiovascular mortality (0.81, 0.72 to 0.90), and cardiovascular disease (0.85, 0.80 to 0.90). High versus low consumption was associated with an 18% lower risk of incident cancer (0.82, 0.74 to 0.89). Consumption was also associated with a lower risk of several specific cancers and neurological, metabolic, and liver conditions. Harmful associations were largely nullified by adequate adjustment for smoking, except in pregnancy, where high versus low/no consumption was associated with low birth weight (odds ratio 1.31, 95% confidence interval 1.03 to 1.67), preterm birth in the first (1.22, 1.00 to 1.49) and second (1

  14. Meta-analyses from a collaborative project in mobile lifelong learning

    NARCIS (Netherlands)

    Arrigo, M.; Kukulska-Hulme, A.; Arnedillo-Sánchez, I.; Kismihók, G.

    2013-01-01

    This paper focuses on the use of mobile technologies in relation to the aims of the European Union's Lifelong Learning programme. First, we explain the background to the notion of mobile lifelong learning. We then present a methodological framework to analyse and identify good practices in mobile

  15. Does Male Circumcision Protect against Sexually Transmitted Infections? Arguments and Meta-Analyses to the Contrary Fail to Withstand Scrutiny.

    Science.gov (United States)

    Morris, Brian J; Hankins, Catherine A; Tobian, Aaron A R; Krieger, John N; Klausner, Jeffrey D

    2014-01-01

    We critically evaluate a recent article by Van Howe involving 12 meta-analyses that concludes, contrary to current evidence, that male circumcision increases the risk of various common sexually transmitted infections (STIs). Our detailed scrutiny reveals that these meta-analyses (1) failed to include results of all relevant studies, especially data from randomized controlled trials, (2) introduced bias through use of inappropriate control groups, (3) altered original data, in the case of human papillomavirus (HPV), by questionable adjustments for "sampling bias," (4) failed to control for confounders through use of crude odds ratios, and (5) used unnecessarily complicated methods without adequate explanation, so impeding replication by others. Interventions that can reduce the prevalence of STIs are important to international health. Of major concern is the global epidemic of oncogenic types of HPV that contribute to the burden of genital cancers. Meta-analyses, when well conducted, can better inform public health policy and medical practice, but when seriously flawed can have detrimental consequences. Our critical evaluation leads us to reject the findings and conclusions of Van Howe on multiple grounds. Our timely analysis thus reaffirms the medical evidence supporting male circumcision as a desirable intervention for STI prevention.

  16. Sleep Characteristics in Children with Attention Deficit Hyperactivity Disorder: Systematic Review and Meta-Analyses.

    Science.gov (United States)

    Díaz-Román, Amparo; Hita-Yáñez, Eva; Buela-Casal, Gualberto

    2016-05-15

    Sleep disturbances have been associated with attention deficit hyperactivity disorder (ADHD), but such relationship is still unclear. The results from the studies conducted do not provide enough evidence to support a sleep physiology inherent to ADHD. This study tries to determine if that sleep physiology really exists by comparing children with ADHD and control children in some sleep parameters. A search was conducted in several databases (Web of Science, Scopus, Pubmed and PsycINFO), and a manual search, to retrieve all the articles available from 1987 until March 2014. Of 8,678 non-duplicate studies retrieved, 11 studies met the inclusion and methodological quality criteria. Two meta-analyses were performed with eight of those studies, depending on data provided by them: polysomnographic or actigraphic. A fixed-effects model, and the standardized mean difference (SMD) as the index of effect size, were used in both meta-analyses. Significant differences were found only in the meta-analysis with polysomnography as outcome. Children with ADHD were found to spend more time in stage 1 sleep than controls (pooled SMD = 0.32, 95% CI = 0.08-0.55, p value = 0.009). Although few differences in sleep between children with ADHD and controls have been found in this review, further studies are required on this matter. Those studies should consider some variables discussed in this review, in order to obtain useful and reliable conclusions for research and clinical practice. Particularly, the influence of assessment criteria and ADHD subtypes in the sleep characteristics of children with ADHD should be addressed. © 2016 American Academy of Sleep Medicine.

  17. How Effective Are Active Videogames Among the Young and the Old? Adding Meta-analyses to Two Recent Systematic Reviews.

    Science.gov (United States)

    van 't Riet, Jonathan; Crutzen, Rik; Lu, Amy Shirong

    2014-10-01

    Two recent systematic reviews have surveyed the existing evidence for the effectiveness of active videogames in children/adolescents and in elderly people. In the present study, effect sizes were added to these systematic reviews, and meta-analyses were performed. All reviewed studies were considered for inclusion in the meta-analyses, but only studies were included that investigated the effectiveness of active videogames, used an experimental design, and used actual health outcomes as the outcome measures (body mass index for children/adolescents [k=5] and functional balance for the elderly [k=6]). The average effect of active videogames in children and adolescents was small and nonsignificant: Hedges' g=0.20 (95 percent confidence interval, -0.08 to 0.48). Limited heterogeneity was observed, and no moderator analyses were performed. For the effect of active videogames on functional balance in the elderly, the analyses revealed a medium-sized and significant effect of g=0.68 (95 percent confidence interval, 0.13-1.24). For the elderly studies, substantial heterogeneity was observed. Moderator analyses showed that there were no significant effects of using a no-treatment control group versus an alternative treatment control group or of using games that were especially created for health-promotion purposes versus off-the-shelf games. Also, intervention duration and frequency, sample size, study quality, and dropout did not significantly moderate the effect of active videogames. The results of these meta-analyses provide preliminary evidence that active videogames can have positive effects on relevant outcome measures in children/adolescents and elderly individuals.

  18. Uncertainty Analyses for Back Projection Methods

    Science.gov (United States)

    Zeng, H.; Wei, S.; Wu, W.

    2017-12-01

    So far few comprehensive error analyses for back projection methods have been conducted, although it is evident that high frequency seismic waves can be easily affected by earthquake depth, focal mechanisms and the Earth's 3D structures. Here we perform 1D and 3D synthetic tests for two back projection methods, MUltiple SIgnal Classification (MUSIC) (Meng et al., 2011) and Compressive Sensing (CS) (Yao et al., 2011). We generate synthetics for both point sources and finite rupture sources with different depths, focal mechanisms, as well as 1D and 3D structures in the source region. The 3D synthetics are generated through a hybrid scheme of Direct Solution Method and Spectral Element Method. Then we back project the synthetic data using MUSIC and CS. The synthetic tests show that the depth phases can be back projected as artificial sources both in space and time. For instance, for a source depth of 10km, back projection gives a strong signal 8km away from the true source. Such bias increases with depth, e.g., the error of horizontal location could be larger than 20km for a depth of 40km. If the array is located around the nodal direction of direct P-waves the teleseismic P-waves are dominated by the depth phases. Therefore, back projections are actually imaging the reflection points of depth phases more than the rupture front. Besides depth phases, the strong and long lasted coda waves due to 3D effects near trench can lead to additional complexities tested here. The strength contrast of different frequency contents in the rupture models also produces some variations to the back projection results. In the synthetic tests, MUSIC and CS derive consistent results. While MUSIC is more computationally efficient, CS works better for sparse arrays. In summary, our analyses indicate that the impact of various factors mentioned above should be taken into consideration when interpreting back projection images, before we can use them to infer the earthquake rupture physics.

  19. Benefits of Exercise Training For Computer-Based Staff: A Meta Analyses

    Directory of Open Access Journals (Sweden)

    Mothna Mohammed

    2017-04-01

    Full Text Available Background: Office workers sit down to work for approximately 8 hours a day and, as a result, many of them do not have enough time for any form of physical exercise. This can lead to musculoskeletal discomforts, especially low back pain and recently, many researchers focused on home/office-based exercise training for prevention/treatment of low back pain among this population. Objective: This Meta analyses paper tried to discuss about the latest suggested exercises for the office workers based on the mechanisms and theories behind low back pain among office workers. Method: In this Meta analyses the author tried to collect relevant papers which were published previously on the subject. Google Scholar, Scopus, and PubMed were used as sources to find the articles. Only articles that were published using the same methodology, including office workers, musculoskeletal discomforts, low back pain, and exercise training keywords, were selected. Studies that failed to report sufficient sample statistics, or lacked a substantial review of past academic scholarship and/or clear methodologies, were excluded. Results: Limited evidence regarding the prevention of, and treatment methods for, musculoskeletal discomfort, especially those in the low back, among office workers, is available. The findings showed that training exercises had a significant effect (p<0.05 on low back pain discomfort scores and decreased pain levels in response to office-based exercise training. Conclusion: Office-based exercise training can affect pain/discomfort scores among office workers through positive effects on flexibility and strength of muscles. As such, it should be suggested to occupational therapists as a practical way for the treatment/prevention of low back pain among office workers.

  20. Electroconvulsive therapy in the continuation and maintenance treatment of depression: Systematic review and meta-analyses.

    Science.gov (United States)

    Elias, Alby; Phutane, Vivek H; Clarke, Sandy; Prudic, Joan

    2018-05-01

    Acute course of electroconvulsive therapy is effective in inducing remission from depression, but recurrence rate is unacceptably high following termination of electroconvulsive therapy despite continued pharmacotherapy. Continuation electroconvulsive therapy and maintenance electroconvulsive therapy have been studied for their efficacy in preventing relapse and recurrence of depression. The purpose of this meta-analysis was to examine the efficacy of continuation electroconvulsive therapy and maintenance electroconvulsive therapy in preventing relapse and recurrence of depression in comparison to antidepressant pharmacotherapy alone. We searched MEDLINE, Embase, PsycINFO, clinicaltrials.gov and Cochrane register of controlled trials from the database inception to December 2016 without restriction on language or publication status for randomized trials of continuation electroconvulsive therapy and maintenance electroconvulsive therapy. Two independent Cochrane reviewers extracted the data in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic reviews and meta-analyses. The risk of bias was assessed using four domains of the Cochrane Collaboration Risk of Bias Tool. Outcomes were pooled using random effect model. The primary outcome was relapse or recurrence of depression. Five studies involving 436 patients were included in the meta-analysis. Analysis of the pooled data showed that continuation electroconvulsive therapy and maintenance electroconvulsive therapy, both with pharmacotherapy, were associated with significantly fewer relapses and recurrences than pharmacotherapy alone at 6 months and 1 year after a successful acute course of electroconvulsive therapy (risk ratio = 0.64, 95% confidence interval = [0.41, 0.98], p = 0.04, risk ratio = 0.46, 95% confidence interval = [0.21, 0.98], p = 0.05, respectively). There was insufficient data to perform a meta-analysis of stand

  1. Meta-DiSc: a software for meta-analysis of test accuracy data.

    Science.gov (United States)

    Zamora, Javier; Abraira, Victor; Muriel, Alfonso; Khan, Khalid; Coomarasamy, Arri

    2006-07-12

    Systematic reviews and meta-analyses of test accuracy studies are increasingly being recognised as central in guiding clinical practice. However, there is currently no dedicated and comprehensive software for meta-analysis of diagnostic data. In this article, we present Meta-DiSc, a Windows-based, user-friendly, freely available (for academic use) software that we have developed, piloted, and validated to perform diagnostic meta-analysis. Meta-DiSc a) allows exploration of heterogeneity, with a variety of statistics including chi-square, I-squared and Spearman correlation tests, b) implements meta-regression techniques to explore the relationships between study characteristics and accuracy estimates, c) performs statistical pooling of sensitivities, specificities, likelihood ratios and diagnostic odds ratios using fixed and random effects models, both overall and in subgroups and d) produces high quality figures, including forest plots and summary receiver operating characteristic curves that can be exported for use in manuscripts for publication. All computational algorithms have been validated through comparison with different statistical tools and published meta-analyses. Meta-DiSc has a Graphical User Interface with roll-down menus, dialog boxes, and online help facilities. Meta-DiSc is a comprehensive and dedicated test accuracy meta-analysis software. It has already been used and cited in several meta-analyses published in high-ranking journals. The software is publicly available at http://www.hrc.es/investigacion/metadisc_en.htm.

  2. [Inguinal hernia repair: results of randomized clinical trials and meta-analyses].

    Science.gov (United States)

    Slim, K; Vons, C

    2008-01-01

    This evidence-based review of the literature aims to answer two questions regarding inguinal hernia repair: 1. should a prosthetic patch be used routinely? 2. Which approach is better - laparoscopic or open surgery? After a comprehensive search of electronic databases we retained only meta-analyses (n=14) and/or randomised clinical trials (n=4). Review of this literature suggests with a good level of evidence that prosthetic hernia repair is the gold standard; the laparoscopic approach has very few proven benefits and may involve more serious complications when performed outside expert centers. The role of laparoscopy for the repair of bilateral or recurrent hernias needs better evaluation.

  3. Unemployment Impairs Mental Health: Meta-Analyses

    Science.gov (United States)

    Paul, Karsten I.; Moser, Klaus

    2009-01-01

    The effect of unemployment on mental health was examined with meta-analytic methods across 237 cross-sectional and 87 longitudinal studies. The average overall effect size was d = 0.51 with unemployed persons showing more distress than employed persons. A significant difference was found for several indicator variables of mental health (mixed…

  4. The PRISMA extension statement for reporting of systematic reviews incorporating network meta-analyses of health care interventions

    DEFF Research Database (Denmark)

    Hutton, Brian; Salanti, Georgia; Caldwell, Deborah M

    2015-01-01

    The PRISMA statement is a reporting guideline designed to improve the completeness of reporting of systematic reviews and meta-analyses. Authors have used this guideline worldwide to prepare their reviews for publication. In the past, these reports typically compared 2 treatment alternatives. Wit...

  5. Meta-Analysis for Sociology – A Measure-Driven Approach

    Science.gov (United States)

    Roelfs, David J.; Shor, Eran; Falzon, Louise; Davidson, Karina W.; Schwartz, Joseph E.

    2013-01-01

    Meta-analytic methods are becoming increasingly important in sociological research. In this article we present an approach for meta-analysis which is especially helpful for sociologists. Conventional approaches to meta-analysis often prioritize “concept-driven” literature searches. However, in disciplines with high theoretical diversity, such as sociology, this search approach might constrain the researcher’s ability to fully exploit the entire body of relevant work. We explicate a “measure-driven” approach, in which iterative searches and new computerized search techniques are used to increase the range of publications found (and thus the range of possible analyses) and to traverse time and disciplinary boundaries. We demonstrate this measure-driven search approach with two meta-analytic projects, examining the effects of various social variables on all-cause mortality. PMID:24163498

  6. Dietary supplement use and colorectal cancer risk: A systematic review and meta-analyses of prospective cohort studies

    NARCIS (Netherlands)

    Heine-Bröring, R.C.; Winkels, R.M.; Renkema, J.M.S.; Kragt, L.; Orten-Luiten, van A.C.B.; Tigchelaar, E.F.; Chan, D.S.M.; Norat, T.; Kampman, E.

    2015-01-01

    Use of dietary supplements is rising in countries where colorectal cancer is prevalent. We conducted a systematic literature review and meta-analyses of prospective cohort studies on dietary supplement use and colorectal cancer risk. We identified relevant studies in Medline, Embase and Cochrane up

  7. metaBIT, an integrative and automated metagenomic pipeline for analysing microbial profiles from high-throughput sequencing shotgun data

    DEFF Research Database (Denmark)

    Louvel, Guillaume; Der Sarkissian, Clio; Hanghøj, Kristian Ebbesen

    2016-01-01

    -throughput DNA sequencing (HTS). Here, we develop metaBIT, an open-source computational pipeline automatizing routine microbial profiling of shotgun HTS data. Customizable by the user at different stringency levels, it performs robust taxonomy-based assignment and relative abundance calculation of microbial taxa......, as well as cross-sample statistical analyses of microbial diversity distributions. We demonstrate the versatility of metaBIT within a range of published HTS data sets sampled from the environment (soil and seawater) and the human body (skin and gut), but also from archaeological specimens. We present......-friendly profiling of the microbial DNA present in HTS shotgun data sets. The applications of metaBIT are vast, from monitoring of laboratory errors and contaminations, to the reconstruction of past and present microbiota, and the detection of candidate species, including pathogens....

  8. Management of hepatocellular carcinoma: an overview of major findings from meta-analyses

    Science.gov (United States)

    Guo, Xiaozhong; Han, Guohong

    2016-01-01

    This paper aims to systematically review the major findings from meta-analyses comparing different treatment options for hepatocellular carcinoma (HCC). A total of 153 relevant papers were searched via the PubMed, EMBASE, and Cochrane library databases. They were classified according to the mainstay treatment modalities (i.e., liver transplantation, surgical resection, radiofrequency ablation, transarterial embolization or chemoembolization, sorafenib, and others). The primary outcome data, such as overall survival, diseases-free survival or recurrence-free survival, progression-free survival, and safety, were summarized. The recommendations and uncertainties regarding the treatment of HCC were also proposed. PMID:27167195

  9. Right-handers have negligibly higher IQ scores than left-handers: Systematic review and meta-analyses.

    Science.gov (United States)

    Ntolka, Eleni; Papadatou-Pastou, Marietta

    2018-01-01

    The relationship between intelligence and handedness remains a matter of debate. The present study is a systematic review of 36 studies (totaling 66,108 individuals), which have measured full IQ scores in different handedness groups. Eighteen of those studies were further included in three sets of meta-analyses (totaling 20,442 individuals), which investigated differences in standardized mean IQ scores in (i) left-handers, (ii) non-right-handers, and (iii) mixed-handers compared to right-handers. The bulk of the studies included in the systematic review reported no differences in IQ scores between left- and right-handers. In the meta-analyses, statistically significant differences in mean IQ scores were detected between right-handers and left-handers, but were marginal in magnitude (d=-0.07); the data sets were found to be homogeneous. Significance was lost when the largest study was excluded. No differences in mean IQ scores were found between right-handers and non-right-handers as well as between right-handers and mixed-handers. No sex differences were found. Overall, the intelligence differences between handedness groups in the general population are negligible. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. How to Make Nothing Out of Something: Analyses of the Impact of Study Sampling and Statistical Interpretation in Misleading Meta-Analytic Conclusions

    Directory of Open Access Journals (Sweden)

    Michael Robert Cunningham

    2016-10-01

    Full Text Available The limited resource model states that self-control is governed by a relatively finite set of inner resources on which people draw when exerting willpower. Once self-control resources have been used up or depleted, they are less available for other self-control tasks, leading to a decrement in subsequent self-control success. The depletion effect has been studied for over 20 years, tested or extended in more than 600 studies, and supported in an independent meta-analysis (Hagger, Wood, Stiff, and Chatzisarantis, 2010. Meta-analyses are supposed to reduce bias in literature reviews. Carter, Kofler, Forster, and McCullough’s (2015 meta-analysis, by contrast, included a series of questionable decisions involving sampling, methods, and data analysis. We provide quantitative analyses of key sampling issues: exclusion of many of the best depletion studies based on idiosyncratic criteria and the emphasis on mini meta-analyses with low statistical power as opposed to the overall depletion effect. We discuss two key methodological issues: failure to code for research quality, and the quantitative impact of weak studies by novice researchers. We discuss two key data analysis issues: questionable interpretation of the results of trim and fill and funnel plot asymmetry test procedures, and the use and misinterpretation of the untested Precision Effect Test [PET] and Precision Effect Estimate with Standard Error (PEESE procedures. Despite these serious problems, the Carter et al. meta-analysis results actually indicate that there is a real depletion effect – contrary to their title.

  11. The Neural Bases of Difficult Speech Comprehension and Speech Production: Two Activation Likelihood Estimation (ALE) Meta-Analyses

    Science.gov (United States)

    Adank, Patti

    2012-01-01

    The role of speech production mechanisms in difficult speech comprehension is the subject of on-going debate in speech science. Two Activation Likelihood Estimation (ALE) analyses were conducted on neuroimaging studies investigating difficult speech comprehension or speech production. Meta-analysis 1 included 10 studies contrasting comprehension…

  12. 78 FR 63479 - Meta-Analyses of Randomized Controlled Clinical Trials (RCTs) for the Evaluation of Risk To...

    Science.gov (United States)

    2013-10-24

    ... pharmaceutical industry and health care organizations, and others from the general public, about the use of meta-analyses of randomized trials as a tool for safety assessment in the regulation of pharmaceutical products... PDUFA Goals Letter, titled ``Enhancing Regulatory Science and Expediting Drug Development,'' includes an...

  13. Formalizing the definition of meta-analysis in Molecular Ecology.

    Science.gov (United States)

    ArchMiller, Althea A; Bauer, Eric F; Koch, Rebecca E; Wijayawardena, Bhagya K; Anil, Ammu; Kottwitz, Jack J; Munsterman, Amelia S; Wilson, Alan E

    2015-08-01

    Meta-analysis, the statistical synthesis of pertinent literature to develop evidence-based conclusions, is relatively new to the field of molecular ecology, with the first meta-analysis published in the journal Molecular Ecology in 2003 (Slate & Phua 2003). The goal of this article is to formalize the definition of meta-analysis for the authors, editors, reviewers and readers of Molecular Ecology by completing a review of the meta-analyses previously published in this journal. We also provide a brief overview of the many components required for meta-analysis with a more specific discussion of the issues related to the field of molecular ecology, including the use and statistical considerations of Wright's FST and its related analogues as effect sizes in meta-analysis. We performed a literature review to identify articles published as 'meta-analyses' in Molecular Ecology, which were then evaluated by at least two reviewers. We specifically targeted Molecular Ecology publications because as a flagship journal in this field, meta-analyses published in Molecular Ecology have the potential to set the standard for meta-analyses in other journals. We found that while many of these reviewed articles were strong meta-analyses, others failed to follow standard meta-analytical techniques. One of these unsatisfactory meta-analyses was in fact a secondary analysis. Other studies attempted meta-analyses but lacked the fundamental statistics that are considered necessary for an effective and powerful meta-analysis. By drawing attention to the inconsistency of studies labelled as meta-analyses, we emphasize the importance of understanding the components of traditional meta-analyses to fully embrace the strengths of quantitative data synthesis in the field of molecular ecology. © 2015 John Wiley & Sons Ltd.

  14. Ain't Necessarily So : Review and Critique of Recent Meta-Analyses of Behavioral Medicine Interventions in Health Psychology

    NARCIS (Netherlands)

    Coyne, James C.; Thombs, Brett D.; Hagedoorn, Mariet

    Objective: We examined four meta-analyses of behavioral interventions for adults (Dixon, Keefe, Scipio, Perri, & Abernethy, 2007; Hoffman, Papas, Chatkoff, & Kerns, 2007; Irwin, Cole, & Nicassio, 2006; and Jacobsen, Donovan, Vadaparampil, & Small, 2007) that have appeared in the Evidence Based

  15. Effects of Exercise in the Treatment of Overweight and Obese Children and Adolescents: A Systematic Review of Meta-Analyses

    Directory of Open Access Journals (Sweden)

    George A. Kelley

    2013-01-01

    Full Text Available Purpose. Conduct a systematic review of previous meta-analyses addressing the effects of exercise in the treatment of overweight and obese children and adolescents. Methods. Previous meta-analyses of randomized controlled exercise trials that assessed adiposity in overweight and obese children and adolescents were included by searching nine electronic databases and cross-referencing from retrieved studies. Methodological quality was assessed using the Assessment of Multiple Systematic Reviews (AMSTAR Instrument. The alpha level for statistical significance was set at P≤0.05. Results. Of the 308 studies reviewed, two aggregate data meta-analyses representing 14 and 17 studies and 481 and 701 boys and girls met all eligibility criteria. Methodological quality was 64% and 73%. For both studies, statistically significant reductions in percent body fat were observed (P=0.006 and P<0.00001. The number-needed-to treat (NNT was 4 and 3 with an estimated 24.5 and 31.5 million overweight and obese children in the world potentially benefitting, 2.8 and 3.6 million in the US. No other measures of adiposity (BMI-related measures, body weight, and central obesity were statistically significant. Conclusions. Exercise is efficacious for reducing percent body fat in overweight and obese children and adolescents. Insufficient evidence exists to suggest that exercise reduces other measures of adiposity.

  16. Research Pearls: The Significance of Statistics and Perils of Pooling. Part 3: Pearls and Pitfalls of Meta-analyses and Systematic Reviews.

    Science.gov (United States)

    Harris, Joshua D; Brand, Jefferson C; Cote, Mark P; Dhawan, Aman

    2017-08-01

    Within the health care environment, there has been a recent and appropriate trend towards emphasizing the value of care provision. Reduced cost and higher quality improve the value of care. Quality is a challenging, heterogeneous, variably defined concept. At the core of quality is the patient's outcome, quantified by a vast assortment of subjective and objective outcome measures. There has been a recent evolution towards evidence-based medicine in health care, clearly elucidating the role of high-quality evidence across groups of patients and studies. Synthetic studies, such as systematic reviews and meta-analyses, are at the top of the evidence-based medicine hierarchy. Thus, these investigations may be the best potential source of guiding diagnostic, therapeutic, prognostic, and economic medical decision making. Systematic reviews critically appraise and synthesize the best available evidence to provide a conclusion statement (a "take-home point") in response to a specific answerable clinical question. A meta-analysis uses statistical methods to quantitatively combine data from single studies. Meta-analyses should be performed with high methodological quality homogenous studies (Level I or II) or evidence randomized studies, to minimize confounding variable bias. When it is known that the literature is inadequate or a recent systematic review has already been performed with a demonstration of insufficient data, then a new systematic review does not add anything meaningful to the literature. PROSPERO registration and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines assist authors in the design and conduct of systematic reviews and should always be used. Complete transparency of the conduct of the review permits reproducibility and improves fidelity of the conclusions. Pooling of data from overly dissimilar investigations should be avoided. This particularly applies to Level IV evidence, that is, noncomparative investigations

  17. Meta-analyses of workplace physical activity and dietary behaviour interventions on weight outcomes.

    Science.gov (United States)

    Verweij, L M; Coffeng, J; van Mechelen, W; Proper, K I

    2011-06-01

    This meta-analytic review critically examines the effectiveness of workplace interventions targeting physical activity, dietary behaviour or both on weight outcomes. Data could be extracted from 22 studies published between 1980 and November 2009 for meta-analyses. The GRADE approach was used to determine the level of evidence for each pooled outcome measure. Results show moderate quality of evidence that workplace physical activity and dietary behaviour interventions significantly reduce body weight (nine studies; mean difference [MD]-1.19 kg [95% CI -1.64 to -0.74]), body mass index (BMI) (11 studies; MD -0.34 kg m⁻² [95% CI -0.46 to -0.22]) and body fat percentage calculated from sum of skin-folds (three studies; MD -1.12% [95% CI -1.86 to -0.38]). There is low quality of evidence that workplace physical activity interventions significantly reduce body weight and BMI. Effects on percentage body fat calculated from bioelectrical impedance or hydrostatic weighing, waist circumference, sum of skin-folds and waist-hip ratio could not be investigated properly because of a lack of studies. Subgroup analyses showed a greater reduction in body weight of physical activity and diet interventions containing an environmental component. As the clinical relevance of the pooled effects may be substantial on a population level, we recommend workplace physical activity and dietary behaviour interventions, including an environment component, in order to prevent weight gain. © 2010 The Authors. obesity reviews © 2010 International Association for the Study of Obesity.

  18. A systematic review of the quality of conduct and reporting of systematic reviews and meta-analyses in paediatric surgery.

    Directory of Open Access Journals (Sweden)

    Paul Stephen Cullis

    Full Text Available Our objective was to evaluate quality of conduct and reporting of published systematic reviews and meta-analyses in paediatric surgery. We also aimed to identify characteristics predictive of review quality.Systematic reviews summarise evidence by combining sources, but are potentially prone to bias. To counter this, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA was published to aid in reporting. Similarly, the Assessing the Methodological Quality of Systematic Reviews (AMSTAR measurement tool was designed to appraise methodology. The paediatric surgical literature has seen an increasing number of reviews over the past decade, but quality has not been evaluated.Adhering to PRISMA guidelines, we performed a systematic review with a priori design to identify systematic reviews and meta-analyses of interventions in paediatric surgery. From 01/2010 to 06/2016, we searched: MEDLINE, EMBASE, Cochrane, Centre for Reviews and Dissemination, Web of Science, Google Scholar, reference lists and journals. Two reviewers independently selected studies and extracted data. We assessed conduct and reporting using AMSTAR and PRISMA. Scores were calculated as the sum of reported items. We also extracted author, journal and article characteristics, and used them in exploratory analysis to determine which variables predict quality.112 articles fulfilled eligibility criteria (53 systematic reviews; 59 meta-analyses. Overall, 68% AMSTAR and 56.8% PRISMA items were reported adequately. Poorest scores were identified with regards a priori design, inclusion of structured summaries, including the grey literature, citing excluded articles and evaluating bias. 13 reviews were pre-registered and 6 in PRISMA-endorsing journals. The following predicted quality in univariate analysis:, word count, Cochrane review, journal h-index, impact factor, journal endorses PRISMA, PRISMA adherence suggested in author guidance, article mentions PRISMA

  19. The effects of 'ecstasy' (MDMA) on visuospatial memory performance: findings from a systematic review with meta-analyses.

    Science.gov (United States)

    Murphy, Philip N; Bruno, Raimondo; Ryland, Ida; Wareing, Michele; Fisk, John E; Montgomery, Catharine; Hilton, Joanne

    2012-03-01

    To review, with meta-analyses where appropriate, performance differences between ecstasy (3,4-methylenedioxymethamphetamine) users and non-users on a wider range of visuospatial tasks than previously reviewed. Such tasks have been shown to draw upon working memory executive resources. Abstract databases were searched using the United Kingdom National Health Service Evidence Health Information Resource. Inclusion criteria were publication in English language peer-reviewed journals and the reporting of new findings regarding human ecstasy-users' performance on visuospatial tasks. Data extracted included specific task requirements to provide a basis for meta-analyses for categories of tasks with similar requirements. Fifty-two studies were identified for review, although not all were suitable for meta-analysis. Significant weighted mean effect sizes indicating poorer performance by ecstasy users compared with matched controls were found for tasks requiring recall of spatial stimulus elements, recognition of figures and production/reproduction of figures. There was no evidence of a linear relationship between estimated ecstasy consumption and effect sizes. Given the networked nature of processing for spatial and non-spatial visual information, future scanning and imaging studies should focus on brain activation differences between ecstasy users and non-users in the context of specific tasks to facilitate identification of loci of potentially compromised activity in users. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia

    NARCIS (Netherlands)

    Verhoeven, Virginie J. M.; Hysi, Pirro G.; Wojciechowski, Robert; Fan, Qiao; Guggenheim, Jeremy A.; Höhn, René; Macgregor, Stuart; Hewitt, Alex W.; Nag, Abhishek; Cheng, Ching-Yu; Yonova-Doing, Ekaterina; Zhou, Xin; Ikram, M. Kamran; Buitendijk, Gabriëlle H. S.; McMahon, George; Kemp, John P.; Pourcain, Beate St; Simpson, Claire L.; Mäkelä, Kari-Matti; Lehtimäki, Terho; Kähönen, Mika; Paterson, Andrew D.; Hosseini, S. Mohsen; Wong, Hoi Suen; Xu, Liang; Jonas, Jost B.; Pärssinen, Olavi; Wedenoja, Juho; Yip, Shea Ping; Ho, Daniel W. H.; Pang, Chi Pui; Chen, Li Jia; Burdon, Kathryn P.; Craig, Jamie E.; Klein, Barbara E. K.; Klein, Ronald; Haller, Toomas; Metspalu, Andres; Khor, Chiea-Chuen; Tai, E.-Shyong; Aung, Tin; Vithana, Eranga; Tay, Wan-Ting; Barathi, Veluchamy A.; Chen, Peng; Li, Ruoying; Liao, Jiemin; Zheng, Yingfeng; Bergen, Arthur A. B.; Chen, Wei

    2013-01-01

    Refractive error is the most common eye disorder worldwide and is a prominent cause of blindness. Myopia affects over 30% of Western populations and up to 80% of Asians. The CREAM consortium conducted genome-wide meta-analyses, including 37,382 individuals from 27 studies of European ancestry and

  1. Projecting meat and cereals demand for China based on a meta-analysis of income elasticities

    OpenAIRE

    Zhou, De; Yu, Xiaohua; Abler, David; Chen, Danhong

    2014-01-01

    There are many projections for China’s food demand, and the projection results differ significantly from each other. Different values for income elasticities could be a major reason. This study projects meat and cereals demand for China based on a meta-analysis of the income elasticity estimates using a collection of 143 and 240 income elasticity estimates for cereals and meat products, respectively, from 36 primary studies. We find that income elasticities for most cereals (general cereals, ...

  2. Limitations and risks of meta-analyses of longevity studies

    DEFF Research Database (Denmark)

    Sebastiani, Paola; Bae, Harold; Gurinovich, Anastasia

    2017-01-01

    Searching for genetic determinants of human longevity has been challenged by the rarity of data sets with large numbers of individuals who have reached extreme old age, inconsistent definitions of the phenotype, and the difficulty of defining appropriate controls. Meta-analysis - a statistical...... method to summarize results from different studies - has become a common tool in genetic epidemiology to accrue large sample sizes for powerful genetic association studies. In conducting a meta-analysis of studies of human longevity however, particular attention must be made to the definition of cases...... and controls (including their health status) and on the effect of possible confounders such as sex and ethnicity upon the genetic effect to be estimated. We will show examples of how a meta-analysis can inflate the false negative rates of genetic association studies or it can bias estimates of the association...

  3. The Influence of Judgment Calls on Meta-Analytic Findings.

    Science.gov (United States)

    Tarrahi, Farid; Eisend, Martin

    2016-01-01

    Previous research has suggested that judgment calls (i.e., methodological choices made in the process of conducting a meta-analysis) have a strong influence on meta-analytic findings and question their robustness. However, prior research applies case study comparison or reanalysis of a few meta-analyses with a focus on a few selected judgment calls. These studies neglect the fact that different judgment calls are related to each other and simultaneously influence the outcomes of a meta-analysis, and that meta-analytic findings can vary due to non-judgment call differences between meta-analyses (e.g., variations of effects over time). The current study analyzes the influence of 13 judgment calls in 176 meta-analyses in marketing research by applying a multivariate, multilevel meta-meta-analysis. The analysis considers simultaneous influences from different judgment calls on meta-analytic effect sizes and controls for alternative explanations based on non-judgment call differences between meta-analyses. The findings suggest that judgment calls have only a minor influence on meta-analytic findings, whereas non-judgment call differences between meta-analyses are more likely to explain differences in meta-analytic findings. The findings support the robustness of meta-analytic results and conclusions.

  4. Does risk management contribute to IT project success? A meta-analysis of empirical evidence

    NARCIS (Netherlands)

    de Bakker, K.F.C.; Boonstra, A.; Wortmann, J.C.

    The question whether risk management contributes to IT project success is considered relevant by people from both academic and practitioners' communities already for a long time. This paper presents a meta-analysis of the empirical evidence that either supports or opposes the claim that risk

  5. Features of Computer-Based Decision Aids: Systematic Review, Thematic Synthesis, and Meta-Analyses

    Science.gov (United States)

    Krömker, Dörthe; Meguerditchian, Ari N; Tamblyn, Robyn

    2016-01-01

    Background Patient information and education, such as decision aids, are gradually moving toward online, computer-based environments. Considerable research has been conducted to guide content and presentation of decision aids. However, given the relatively new shift to computer-based support, little attention has been given to how multimedia and interactivity can improve upon paper-based decision aids. Objective The first objective of this review was to summarize published literature into a proposed classification of features that have been integrated into computer-based decision aids. Building on this classification, the second objective was to assess whether integration of specific features was associated with higher-quality decision making. Methods Relevant studies were located by searching MEDLINE, Embase, CINAHL, and CENTRAL databases. The review identified studies that evaluated computer-based decision aids for adults faced with preference-sensitive medical decisions and reported quality of decision-making outcomes. A thematic synthesis was conducted to develop the classification of features. Subsequently, meta-analyses were conducted based on standardized mean differences (SMD) from randomized controlled trials (RCTs) that reported knowledge or decisional conflict. Further subgroup analyses compared pooled SMDs for decision aids that incorporated a specific feature to other computer-based decision aids that did not incorporate the feature, to assess whether specific features improved quality of decision making. Results Of 3541 unique publications, 58 studies met the target criteria and were included in the thematic synthesis. The synthesis identified six features: content control, tailoring, patient narratives, explicit values clarification, feedback, and social support. A subset of 26 RCTs from the thematic synthesis was used to conduct the meta-analyses. As expected, computer-based decision aids performed better than usual care or alternative aids; however

  6. Features of Computer-Based Decision Aids: Systematic Review, Thematic Synthesis, and Meta-Analyses.

    Science.gov (United States)

    Syrowatka, Ania; Krömker, Dörthe; Meguerditchian, Ari N; Tamblyn, Robyn

    2016-01-26

    Patient information and education, such as decision aids, are gradually moving toward online, computer-based environments. Considerable research has been conducted to guide content and presentation of decision aids. However, given the relatively new shift to computer-based support, little attention has been given to how multimedia and interactivity can improve upon paper-based decision aids. The first objective of this review was to summarize published literature into a proposed classification of features that have been integrated into computer-based decision aids. Building on this classification, the second objective was to assess whether integration of specific features was associated with higher-quality decision making. Relevant studies were located by searching MEDLINE, Embase, CINAHL, and CENTRAL databases. The review identified studies that evaluated computer-based decision aids for adults faced with preference-sensitive medical decisions and reported quality of decision-making outcomes. A thematic synthesis was conducted to develop the classification of features. Subsequently, meta-analyses were conducted based on standardized mean differences (SMD) from randomized controlled trials (RCTs) that reported knowledge or decisional conflict. Further subgroup analyses compared pooled SMDs for decision aids that incorporated a specific feature to other computer-based decision aids that did not incorporate the feature, to assess whether specific features improved quality of decision making. Of 3541 unique publications, 58 studies met the target criteria and were included in the thematic synthesis. The synthesis identified six features: content control, tailoring, patient narratives, explicit values clarification, feedback, and social support. A subset of 26 RCTs from the thematic synthesis was used to conduct the meta-analyses. As expected, computer-based decision aids performed better than usual care or alternative aids; however, some features performed better than

  7. The role of host genetic factors in respiratory tract infectious diseases: systematic review, meta-analyses and field synopsis

    NARCIS (Netherlands)

    Patarčić, Inga; Gelemanović, Andrea; Kirin, Mirna; Kolčić, Ivana; Theodoratou, Evropi; Baillie, Kenneth J.; de Jong, Menno D.; Rudan, Igor; Campbell, Harry; Polašek, Ozren

    2015-01-01

    Host genetic factors have frequently been implicated in respiratory infectious diseases, often with inconsistent results in replication studies. We identified 386 studies from the total of 24,823 studies identified in a systematic search of four bibliographic databases. We performed meta-analyses of

  8. META-NORD

    DEFF Research Database (Denmark)

    Vasilejev, Andrejs; Pedersen, Bolette Sandford; De Smeth, Koenraad

    2011-01-01

    This position paper presents META-NORD project which develops Nordic and Baltic part of the European open language resource infrastructure. META-NORD works on assembling, linking across languages, and making widely available the basic language resources used by developers, professionals...

  9. Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study

    Science.gov (United States)

    Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias

    2018-01-01

    Abstract Objective To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) (“living” network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Design Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Data sources Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Eligibility criteria for study selection Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (Pmeta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. Results 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis provided strong evidence against the null hypothesis for seven comparisons, but for an additional 10 comparisons only network meta-analysis provided strong evidence against the null hypothesis (P=0.002). The median time to strong evidence against the null hypothesis was 19 years with living network meta-analysis and 23 years with living pairwise meta-analysis (hazard ratio 2.78, 95% confidence interval 1.00 to 7.72, P=0.05). Studies directly comparing

  10. Effectiveness of acupuncture for cancer pain: protocol for an umbrella review and meta-analyses of controlled trials

    Science.gov (United States)

    He, Yihan; Liu, Yihong; May, Brian H; Zhang, Anthony Lin; Zhang, Haibo; Lu, ChuanJian; Yang, Lihong; Guo, Xinfeng; Xue, Charlie Changli

    2017-01-01

    Introduction The National Comprehensive Cancer Network guidelines for adult cancer pain indicate that acupuncture and related therapies may be valuable additions to pharmacological interventions for pain management. Of the systematic reviews related to this topic, some concluded that acupuncture was promising for alleviating cancer pain, while others argued that the evidence was insufficient to support its effectiveness. Methods and analysis This review will consist of three components: (1) synthesis of findings from existing systematic reviews; (2) updated meta-analyses of randomised clinical trials and (3) analyses of results of other types of clinical studies. We will search six English and four Chinese biomedical databases, dissertations and grey literature to identify systematic reviews and primary clinical studies. Two reviewers will screen results of the literature searches independently to identify included reviews and studies. Data from included articles will be abstracted for assessment, analysis and summary. Two assessors will appraise the quality of systematic reviews using Assessment of Multiple Systematic Reviews; assess the randomised controlled trials using the Cochrane Collaboration’s risk of bias tool and other types of studies according to the Newcastle-Ottawa Scale. We will use ‘summary of evidence’ tables to present evidence from existing systematic reviews and meta-analyses. Using the primary clinical studies, we will conduct meta-analysis for each outcome, by grouping studies based on the type of acupuncture, the comparator and the specific type of pain. Sensitivity analyses are planned according to clinical factors, acupuncture method, methodological characteristics and presence of statistical heterogeneity as applicable. For the non-randomised studies, we will tabulate the characteristics, outcome measures and the reported results of each study. Consistencies and inconsistencies in evidence will be investigated and discussed. Finally

  11. Hypnotics and driving safety: meta-analyses of randomized controlled trials applying the on-the-road driving test.

    Science.gov (United States)

    Verster, Joris C; Veldhuijzen, Dieuwke S; Patat, Alain; Olivier, Berend; Volkerts, Edmund R

    2006-01-01

    Many people who use hypnotics are outpatients and are likely to drive a car the day after drug intake. The purpose of these meta-analyses was to determine whether or not this is safe. Placebo-controlled, randomized, double-blind trials were selected if using the on-the-road driving test to determine driving ability the day following one or two nights of treatment administration. Primary outcome measure of the driving test was the Standard Deviation of Lateral Position (SDLP); i.e., the weaving of the car. Fixed effects model meta-analyses were performed. Effect size (ES) was computed using mean standardized (weighted) difference scores between treatment and corresponding placebo SDLP values. Ten studies, published from 1984 to 2002 (207 subjects), were included in the meta-analyses. The morning following bedtime administration, i.e. 10-11 hours after dosing, significant driving impairment was found for the recommended dose of various benzodiazepine hypnotics (ES=0.42; 95% Confidence Interval (CI)=0.14 to 0.71). Twice the recommended dose impaired driving both in the morning (ES=0.68; CI=0.39 to 0.97) and afternoon, i.e. 16-17 hours after dosing (ES=0.57; CI=0.26 to 0.88). Zopiclone 7.5 mg also impaired driving in the morning (ES=0.89; CI=0.54 to 1.23). Zaleplon (10 and 20 mg) and zolpidem (10 mg) did not affect driving performance the morning after dosing. Following middle-of-the-night administration, significantly impaired driving performance was found for zopiclone 7.5 mg (ES=1.51, CI=0.85 to 2.17), zolpidem 10 mg (ES=0.66, CI=0.13 to 1.19) and zolpidem 20 mg (ES=1.16, CI=0.60 to 1.72). Zaleplon (10 and 20 mg) did not affect driving performance. The analyses show that driving a car the morning following nocturnal treatment with benzodiazepines and zopiclone is unsafe, whereas the recommended dose of zolpidem (10 mg) and zaleplon (10 mg) do not affect driving ability.

  12. Brain areas associated with numbers and calculations in children: Meta-analyses of fMRI studies

    Directory of Open Access Journals (Sweden)

    Marie Arsalidou

    2018-04-01

    Full Text Available Children use numbers every day and typically receive formal mathematical training from an early age, as it is a main subject in school curricula. Despite an increase in children neuroimaging studies, a comprehensive neuropsychological model of mathematical functions in children is lacking. Using quantitative meta-analyses of functional magnetic resonance imaging (fMRI studies, we identify concordant brain areas across articles that adhere to a set of selection criteria (e.g., whole-brain analysis, coordinate reports and report brain activity to tasks that involve processing symbolic and non-symbolic numbers with and without formal mathematical operations, which we called respectively number tasks and calculation tasks. We present data on children 14 years and younger, who solved these tasks. Results show activity in parietal (e.g., inferior parietal lobule and precuneus and frontal (e.g., superior and medial frontal gyri cortices, core areas related to mental-arithmetic, as well as brain regions such as the insula and claustrum, which are not typically discussed as part of mathematical problem solving models. We propose a topographical atlas of mathematical processes in children, discuss findings within a developmental constructivist theoretical model, and suggest practical methodological considerations for future studies. Keywords: Mathematical cognition, Meta-analyses, fMRI, Children, Development, Insula

  13. Economic evaluation of algae biodiesel based on meta-analyses

    Science.gov (United States)

    Zhang, Yongli; Liu, Xiaowei; White, Mark A.; Colosi, Lisa M.

    2017-08-01

    The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be 5.00-10.31/gal, higher than the selected benchmarks: 3.77/gal for petroleum diesel, and 4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel (2.76-4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.

  14. Not all risks are created equal: A twin study and meta-analyses of risk taking across seven domains.

    Science.gov (United States)

    Wang, X T Xiao-Tian; Zheng, Rui; Xuan, Yan-Hua; Chen, Jie; Li, Shu

    2016-11-01

    Humans routinely deal with both traditional and novel risks. Different kinds of risks have been a driving force for both evolutionary adaptations and personal development. This study explored the genetic and environmental influences on human risk taking in different task domains. Our approach was threefold. First, we integrated several scales of domain-specific risk-taking propensity and developed a synthetic scale, including both evolutionarily typical and modern risks in the following 7 domains: cooperation/competition, safety, reproduction, natural/physical risk, moral risk, financial risk, and gambling. Second, we conducted a twin study using the scale to estimate the contributions of genes and environment to risk taking in each of these 7 domains. Third, we conducted a series of meta-analyses of extant twin studies across the 7 risk domains. The results showed that individual differences in risk-taking propensity and its consistency across domains were mainly regulated by additive genetic influences and individually unique environmental experiences. The heritability estimates from the meta-analyses ranged from 29% in financial risk taking to 55% in safety. Supporting the notion of risk-domain specificity, both the behavioral and genetic correlations among the 7 domains were generally low. Among the relatively few correlations between pairs of risk domains, our analysis revealed a common genetic factor that regulates moral, financial, and natural/physical risk taking. This is the first effort to separate genetic and environmental influences on risk taking across multiple domains in a single study and integrate the findings of extant twin studies via a series of meta-analyses conducted in different task domains. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

  15. Development of the Veritas plot and its application in cardiac surgery: an evidence-synthesis graphic tool for the clinician to assess multiple meta-analyses reporting on a common outcome.

    Science.gov (United States)

    Panesar, Sukhmeet S; Rao, Christopher; Vecht, Joshua A; Mirza, Saqeb B; Netuveli, Gopalakrishnan; Morris, Richard; Rosenthal, Joe; Darzi, Ara; Athanasiou, Thanos

    2009-10-01

    Meta-analyses may be prone to generating misleading results because of a paucity of experimental studies (especially in surgery); publication bias; and heterogeneity in study design, intervention and the patient population of included studies. When investigating a specific clinical or scientific question on which several relevant meta-analyses may have been published, value judgments must be applied to determine which analysis represents the most robust evidence. These value judgments should be specifically acknowledged. We designed the Veritas plot to explicitly explore important elements of quality and to facilitate decision-making by highlighting specific areas in which meta-analyses are found to be deficient. Furthermore, as a graphic tool, it may be more intuitive than when similar data are presented in a tabular or text format. The Veritas plot is an adaption of the radar plot, a graphic tool for the description of multiattribute data. Key elements of meta-analytical quality such as heterogeneity, publication bias and study design are assessed. Existing qualitative methods such as the Assessment of Multiple Systematic Reviews (AMSTAR) tool have been incorporated in addition to important considerations when interpreting surgical meta-analyses such as the year of publication and population characteristics. To demonstrate the potential of the Veritas plot to inform clinical practice, we apply the Veritas plot to the meta-analytical literature comparing the incidence of 30-day stroke in off-pump coronary artery bypass surgery and conventional coronary artery bypass surgery. We demonstrate that a visually-stimulating and practical evidence-synthesis tool can direct the clinician and scientist to a particular meta-analytical study to inform clinical practice. The Veritas plot is also cumulative and allowed us to assess the quality of evidence over time. We have presented a practical graphic application for scientists and clinicians to identify and interpret

  16. How effective are active videogames among the young and the old? Adding meta-analyses to two recent systematic reviews

    NARCIS (Netherlands)

    Riet, J.P. van 't; Crutzen, R.M.M.; Lu, A.S.

    2014-01-01

    Objective: Two recent systematic reviews have surveyed the existing evidence for the effectiveness of active videogames in children/adolescents and in elderly people. In the present study, effect sizes were added to these systematic reviews, and meta-analyses were performed. Materials and Methods:

  17. Managing complex research datasets using electronic tools: A meta-analysis exemplar

    Science.gov (United States)

    Brown, Sharon A.; Martin, Ellen E.; Garcia, Theresa J.; Winter, Mary A.; García, Alexandra A.; Brown, Adama; Cuevas, Heather E.; Sumlin, Lisa L.

    2013-01-01

    Meta-analyses of broad scope and complexity require investigators to organize many study documents and manage communication among several research staff. Commercially available electronic tools, e.g., EndNote, Adobe Acrobat Pro, Blackboard, Excel, and IBM SPSS Statistics (SPSS), are useful for organizing and tracking the meta-analytic process, as well as enhancing communication among research team members. The purpose of this paper is to describe the electronic processes we designed, using commercially available software, for an extensive quantitative model-testing meta-analysis we are conducting. Specific electronic tools improved the efficiency of (a) locating and screening studies, (b) screening and organizing studies and other project documents, (c) extracting data from primary studies, (d) checking data accuracy and analyses, and (e) communication among team members. The major limitation in designing and implementing a fully electronic system for meta-analysis was the requisite upfront time to: decide on which electronic tools to use, determine how these tools would be employed, develop clear guidelines for their use, and train members of the research team. The electronic process described here has been useful in streamlining the process of conducting this complex meta-analysis and enhancing communication and sharing documents among research team members. PMID:23681256

  18. A Microsoft-Excel-based tool for running and critically appraising network meta-analyses—an overview and application of NetMetaXL

    Science.gov (United States)

    2014-01-01

    Background The use of network meta-analysis has increased dramatically in recent years. WinBUGS, a freely available Bayesian software package, has been the most widely used software package to conduct network meta-analyses. However, the learning curve for WinBUGS can be daunting, especially for new users. Furthermore, critical appraisal of network meta-analyses conducted in WinBUGS can be challenging given its limited data manipulation capabilities and the fact that generation of graphical output from network meta-analyses often relies on different software packages than the analyses themselves. Methods We developed a freely available Microsoft-Excel-based tool called NetMetaXL, programmed in Visual Basic for Applications, which provides an interface for conducting a Bayesian network meta-analysis using WinBUGS from within Microsoft Excel. . This tool allows the user to easily prepare and enter data, set model assumptions, and run the network meta-analysis, with results being automatically displayed in an Excel spreadsheet. It also contains macros that use NetMetaXL’s interface to generate evidence network diagrams, forest plots, league tables of pairwise comparisons, probability plots (rankograms), and inconsistency plots within Microsoft Excel. All figures generated are publication quality, thereby increasing the efficiency of knowledge transfer and manuscript preparation. Results We demonstrate the application of NetMetaXL using data from a network meta-analysis published previously which compares combined resynchronization and implantable defibrillator therapy in left ventricular dysfunction. We replicate results from the previous publication while demonstrating result summaries generated by the software. Conclusions Use of the freely available NetMetaXL successfully demonstrated its ability to make running network meta-analyses more accessible to novice WinBUGS users by allowing analyses to be conducted entirely within Microsoft Excel. NetMetaXL also allows

  19. Living network meta-analysis compared with pairwise meta-analysis in comparative effectiveness research: empirical study.

    Science.gov (United States)

    Nikolakopoulou, Adriani; Mavridis, Dimitris; Furukawa, Toshi A; Cipriani, Andrea; Tricco, Andrea C; Straus, Sharon E; Siontis, George C M; Egger, Matthias; Salanti, Georgia

    2018-02-28

    To examine whether the continuous updating of networks of prospectively planned randomised controlled trials (RCTs) ("living" network meta-analysis) provides strong evidence against the null hypothesis in comparative effectiveness of medical interventions earlier than the updating of conventional, pairwise meta-analysis. Empirical study of the accumulating evidence about the comparative effectiveness of clinical interventions. Database of network meta-analyses of RCTs identified through searches of Medline, Embase, and the Cochrane Database of Systematic Reviews until 14 April 2015. Network meta-analyses published after January 2012 that compared at least five treatments and included at least 20 RCTs. Clinical experts were asked to identify in each network the treatment comparison of greatest clinical interest. Comparisons were excluded for which direct and indirect evidence disagreed, based on side, or node, splitting test (Pmeta-analyses were performed for each selected comparison. Monitoring boundaries of statistical significance were constructed and the evidence against the null hypothesis was considered to be strong when the monitoring boundaries were crossed. A significance level was defined as α=5%, power of 90% (β=10%), and an anticipated treatment effect to detect equal to the final estimate from the network meta-analysis. The frequency and time to strong evidence was compared against the null hypothesis between pairwise and network meta-analyses. 49 comparisons of interest from 44 networks were included; most (n=39, 80%) were between active drugs, mainly from the specialties of cardiology, endocrinology, psychiatry, and rheumatology. 29 comparisons were informed by both direct and indirect evidence (59%), 13 by indirect evidence (27%), and 7 by direct evidence (14%). Both network and pairwise meta-analysis provided strong evidence against the null hypothesis for seven comparisons, but for an additional 10 comparisons only network meta-analysis provided

  20. MetaRep, an extended CMAS 3D program to visualize mafic (CMAS, ACF-S, ACF-N) and pelitic (AFM-K, AFM-S, AKF-S) projections

    Science.gov (United States)

    France, Lydéric; Nicollet, Christian

    2010-06-01

    MetaRep is a program based on our earlier program CMAS 3D. It is developed in MATLAB ® script. MetaRep objectives are to visualize and project major element compositions of mafic and pelitic rocks and their minerals in the pseudo-quaternary projections of the ACF-S, ACF-N, CMAS, AFM-K, AFM-S and AKF-S systems. These six systems are commonly used to describe metamorphic mineral assemblages and magmatic evolutions. Each system, made of four apices, can be represented in a tetrahedron that can be visualized in three dimensions with MetaRep; the four tetrahedron apices represent oxides or combination of oxides that define the composition of the projected rock or mineral. The three-dimensional representation allows one to obtain a better understanding of the topology of the relationships between the rocks and minerals and relations. From these systems, MetaRep can also project data in ternary plots (for example, the ACF, AFM and AKF ternary projections can be generated). A functional interface makes it easy to use and does not require any knowledge of MATLAB ® programming. To facilitate the use, MetaRep loads, from the main interface, data compiled in a Microsoft Excel ™ spreadsheet. Although useful for scientific research, the program is also a powerful tool for teaching. We propose an application example that, by using two combined systems (ACF-S and ACF-N), provides strong confirmation in the petrological interpretation.

  1. Glucocerebrosidase mutations and neuropsychiatric phenotypes in Parkinson's disease and Lewy body dementias: Review and meta-analyses.

    Science.gov (United States)

    Creese, Byron; Bell, Emily; Johar, Iskandar; Francis, Paul; Ballard, Clive; Aarsland, Dag

    2018-03-01

    Heterozygous mutations in glucocerebrosidase gene (GBA) are a major genetic risk factor for Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Recently, there has been a considerable focus on the relationship between GBA mutations and emergence of cognitive impairment and neuropsychiatric symptoms in these diseases. Here, we review the literature in this area, with a particular focus, including meta-analysis, on the key neuropsychiatric symptoms of cognitive impairment, psychosis, and depression in Parkinson's disease. Our meta-analysis demonstrated that GBA mutations are associated with a 2.4-fold increased risk of cognitive impairment. In addition, our novel meta-analyses of psychosis and depression showed a 1.8- and 2.2-fold increased risk respectively associated with GBA mutations, although due to possible bias and heterogeneity the depression findings should be interpreted with caution. While the precise mechanisms which increase susceptibility to neurodegeneration in GBA carriers are not known, evidence of greater cortical Lewy body pathology, reduced patterns of cortical activation, and hippocampal pathology in animal models are all consistent with a direct effect of GBA mutations on these symptoms. Extension of this work in DLB and individuals without neurodegeneration will be important in further characterizing how GBA mutations increase risk for PD and DLB and influence disease course. © 2017 Wiley Periodicals, Inc.

  2. Parent-based adolescent sexual health interventions and effect on communication outcomes: a systematic review and meta-analyses.

    Science.gov (United States)

    Santa Maria, Diane; Markham, Christine; Bluethmann, Shirley; Mullen, Patricia Dolan

    2015-03-01

    Parent-based adolescent sexual health interventions aim to reduce sexual risk behaviors by bolstering parental protective behaviors. Few studies of theory use, methods, applications, delivery and outcomes of parent-based interventions have been conducted. A systematic search of databases for the period 1998-2013 identified 28 published trials of U.S. parent-based interventions to examine theory use, setting, reach, delivery mode, dose and effects on parent-child communication. Established coding schemes were used to assess use of theory and describe methods employed to achieve behavioral change; intervention effects were explored in meta-analyses. Most interventions were conducted with minority parents in group sessions or via self-paced activities; interventions averaged seven hours, and most used theory extensively. Meta-analyses found improvements in sexual health communication: Analysis of 11 controlled trials indicated a medium effect on increasing communication (Cohen's d, 0.5), and analysis of nine trials found a large effect on increasing parental comfort with communication (0.7); effects were positive regardless of delivery mode or intervention dose. Intervention participants were 68% more likely than controls to report increased communication and 75% more likely to report increased comfort. These findings point to gaps in the range of programs examined in published trials-for example, interventions for parents of sexual minority youth, programs for custodial grandparents and faith-based services. Yet they provide support for the effectiveness of parent-based interventions in improving communication. Innovative delivery approaches could extend programs' reach, and further research on sexual health outcomes would facilitate the meta-analysis of intervention effectiveness in improving adolescent sexual health behaviors. Copyright © 2015 by the Guttmacher Institute.

  3. Incorporating uncertainty regarding applicability of evidence from meta-analyses into clinical decision making.

    Science.gov (United States)

    Kriston, Levente; Meister, Ramona

    2014-03-01

    Judging applicability (relevance) of meta-analytical findings to particular clinical decision-making situations remains challenging. We aimed to describe an evidence synthesis method that accounts for possible uncertainty regarding applicability of the evidence. We conceptualized uncertainty regarding applicability of the meta-analytical estimates to a decision-making situation as the result of uncertainty regarding applicability of the findings of the trials that were included in the meta-analysis. This trial-level applicability uncertainty can be directly assessed by the decision maker and allows for the definition of trial inclusion probabilities, which can be used to perform a probabilistic meta-analysis with unequal probability resampling of trials (adaptive meta-analysis). A case study with several fictitious decision-making scenarios was performed to demonstrate the method in practice. We present options to elicit trial inclusion probabilities and perform the calculations. The result of an adaptive meta-analysis is a frequency distribution of the estimated parameters from traditional meta-analysis that provides individually tailored information according to the specific needs and uncertainty of the decision maker. The proposed method offers a direct and formalized combination of research evidence with individual clinical expertise and may aid clinicians in specific decision-making situations. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Serum BDNF concentrations as peripheral manifestations of depression : evidence from a systematic review and meta-analyses on 179 associations (N=9484)

    NARCIS (Netherlands)

    Molendijk, M. L.; Spinhoven, P.; Polak, M.; Bus, B. A. A.; Penninx, B. W. J. H.; Elzinga, B. M.

    Meta-analyses, published in 2008-2010, have confirmed abnormally low serum brain-derived neurotrophic factor (BDNF) concentrations in depressed patients and normalization of this by antidepressant treatment. These findings are believed to reflect peripheral manifestations of the neurotrophin

  5. Gr/gr deletions on Y-chromosome correlate with male infertility: an original study, meta-analyses, and trial sequential analyses

    Science.gov (United States)

    Bansal, Sandeep Kumar; Jaiswal, Deepika; Gupta, Nishi; Singh, Kiran; Dada, Rima; Sankhwar, Satya Narayan; Gupta, Gopal; Rajender, Singh

    2016-02-01

    We analyzed the AZFc region of the Y-chromosome for complete (b2/b4) and distinct partial deletions (gr/gr, b1/b3, b2/b3) in 822 infertile and 225 proven fertile men. We observed complete AZFc deletions in 0.97% and partial deletions in 6.20% of the cases. Among partial deletions, the frequency of gr/gr deletions was the highest (5.84%). The comparison of partial deletion data between cases and controls suggested a significant association of the gr/gr deletions with infertility (P = 0.0004); however, the other partial deletions did not correlate with infertility. In cohort analysis, men with gr/gr deletions had a relatively poor sperm count (54.20 ± 57.45 million/ml) in comparison to those without deletions (72.49 ± 60.06), though the difference was not statistically significant (p = 0.071). Meta-analysis also suggested that gr/gr deletions are significantly associated with male infertility risk (OR = 1.821, 95% CI = 1.39-2.37, p = 0.000). We also performed trial sequential analyses that strengthened the evidence for an overall significant association of gr/gr deletions with the risk of male infertility. Another meta-analysis suggested a significant association of the gr/gr deletions with low sperm count. In conclusion, the gr/gr deletions show a strong correlation with male infertility risk and low sperm count, particularly in the Caucasian populations.

  6. Thirty years of Alzheimer's disease genetics: the implications of systematic meta-analyses.

    Science.gov (United States)

    Bertram, Lars; Tanzi, Rudolph E

    2008-10-01

    The genetic underpinnings of Alzheimer's disease (AD) remain largely elusive despite early successes in identifying three genes that cause early-onset familial AD (those that encode amyloid precursor protein (APP) and the presenilins (PSEN1 and PSEN2)), and one genetic risk factor for late-onset AD (the gene that encodes apolipoprotein E (APOE)). A large number of studies that aimed to help uncover the remaining disease-related loci have been published in recent decades, collectively proposing or refuting the involvement of over 500 different gene candidates. Systematic meta-analyses of these studies currently highlight more than 20 loci that have modest but significant effects on AD risk. This Review discusses the putative pathogenetic roles and common biochemical pathways of some of the most genetically and biologically compelling of these potential AD risk factors.

  7. Alcohol Consumption and the Physical Availability of Take-Away Alcohol: Systematic Reviews and Meta-Analyses of the Days and Hours of Sale and Outlet Density.

    Science.gov (United States)

    Sherk, Adam; Stockwell, Tim; Chikritzhs, Tanya; Andréasson, Sven; Angus, Colin; Gripenberg, Johanna; Holder, Harold; Holmes, John; Mäkelä, Pia; Mills, Megan; Norström, Thor; Ramstedt, Mats; Woods, Jonathan

    2018-01-01

    Systematic reviews and meta-analyses were completed studying the effect of changes in the physical availability of take-away alcohol on per capita alcohol consumption. Previous reviews examining this topic have not focused on off-premise outlets where take-away alcohol is sold and have not completed meta-analyses. Systematic reviews were conducted separately for policies affecting the temporal availability (days and hours of sale) and spatial availability (outlet density) of take-away alcohol. Studies were included up to December 2015. Quality criteria were used to select articles that studied the effect of changes in these policies on alcohol consumption with a focus on natural experiments. Random-effects meta-analyses were applied to produce the estimated effect of an additional day of sale on total and beverage-specific consumption. Separate systematic reviews identified seven studies regarding days and hours of sale and four studies regarding density. The majority of articles included in these systematic reviews, for days/hours of sale (7/7) and outlet density (3/4), concluded that restricting the physical availability of take-away alcohol reduces per capita alcohol consumption. Meta-analyses studying the effect of adding one additional day of sale found that this was associated with per capita consumption increases of 3.4% (95% CI [2.7, 4.1]) for total alcohol, 5.3% (95% CI [3.2, 7.4]) for beer, 2.6% (95% CI [1.8, 3.5]) for wine, and 2.6% (95% CI [2.1, 3.2]) for spirits. The small number of included studies regarding hours of sale and density precluded meta-analysis. The results of this study suggest that decreasing the physical availability of take-away alcohol will decrease per capita consumption. As decreasing per capita consumption has been shown to reduce alcohol-related harm, restricting the physical availability of take-away alcohol would be expected to result in improvements to public health.

  8. Systematic review and meta-analyses of psychosocial interventions for veterans of the military

    Directory of Open Access Journals (Sweden)

    Neil J. Kitchiner

    2012-12-01

    Full Text Available Background: The efficacy of psychosocial therapies for common mental health disorders in veterans is unclear and requires further examination. Method: Systematic review and meta-analyses of randomised controlled trials (RCTs. Twenty databases were searched. Studies were included if they reported a psychosocial intervention designed to treat or reduce common mental health symptoms in veterans identified as being symptomatic at the time they entered the study. Studies of substance dependency disorders and psychosis were excluded. Eligible studies were assessed against methodological quality criteria and data were extracted and analysed. Results: Twenty-nine RCTs were identified. There was evidence for the use of trauma-focused therapies for post-traumatic stress disorder (PTSD and some evidence for psychological interventions in the treatment of borderline personality disorder, depression, insomnia, and panic disorder co-morbid to PTSD. However, methodological quality of many of the studies was less than optimal. Conclusions: Trauma-focused psychological therapies are likely to be effective for combat-related PTSD but there is a need for more research to determine the efficacy of psychological treatments for other mental health disorders in veterans.

  9. Trial Sequential Analysis in systematic reviews with meta-analysis

    DEFF Research Database (Denmark)

    Wetterslev, Jørn; Jakobsen, Janus Christian; Gluud, Christian

    2017-01-01

    BACKGROUND: Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded as an interim analysis on its way towards a required information size...... from traditional meta-analyses using unadjusted naïve 95% confidence intervals and 5% thresholds for statistical significance. Spurious conclusions in systematic reviews with traditional meta-analyses can be reduced using Trial Sequential Analysis. Several empirical studies have demonstrated...

  10. Large-scale genome-wide association studies and meta-analyses of longitudinal change in adult lung function.

    Directory of Open Access Journals (Sweden)

    Wenbo Tang

    Full Text Available Genome-wide association studies (GWAS have identified numerous loci influencing cross-sectional lung function, but less is known about genes influencing longitudinal change in lung function.We performed GWAS of the rate of change in forced expiratory volume in the first second (FEV1 in 14 longitudinal, population-based cohort studies comprising 27,249 adults of European ancestry using linear mixed effects model and combined cohort-specific results using fixed effect meta-analysis to identify novel genetic loci associated with longitudinal change in lung function. Gene expression analyses were subsequently performed for identified genetic loci. As a secondary aim, we estimated the mean rate of decline in FEV1 by smoking pattern, irrespective of genotypes, across these 14 studies using meta-analysis.The overall meta-analysis produced suggestive evidence for association at the novel IL16/STARD5/TMC3 locus on chromosome 15 (P  =  5.71 × 10(-7. In addition, meta-analysis using the five cohorts with ≥3 FEV1 measurements per participant identified the novel ME3 locus on chromosome 11 (P  =  2.18 × 10(-8 at genome-wide significance. Neither locus was associated with FEV1 decline in two additional cohort studies. We confirmed gene expression of IL16, STARD5, and ME3 in multiple lung tissues. Publicly available microarray data confirmed differential expression of all three genes in lung samples from COPD patients compared with controls. Irrespective of genotypes, the combined estimate for FEV1 decline was 26.9, 29.2 and 35.7 mL/year in never, former, and persistent smokers, respectively.In this large-scale GWAS, we identified two novel genetic loci in association with the rate of change in FEV1 that harbor candidate genes with biologically plausible functional links to lung function.

  11. Effects of parenting interventions for at-risk parents with infants: a systematic review and meta-analyses.

    Science.gov (United States)

    Rayce, Signe B; Rasmussen, Ida S; Klest, Sihu K; Patras, Joshua; Pontoppidan, Maiken

    2017-12-27

    Infancy is a critical stage of life, and a secure relationship with caring and responsive caregivers is crucial for healthy infant development. Early parenting interventions aim to support families in which infants are at risk of developmental harm. Our objective is to systematically review the effects of parenting interventions on child development and on parent-child relationship for at-risk families with infants aged 0-12 months. This is a systematic review and meta-analyses. We extracted publications from 10 databases in June 2013, January 2015 and June 2016, and supplemented with grey literature and hand search. We assessed risk of bias, calculated effect sizes and conducted meta-analyses. (1) Randomised controlled trials of structured psychosocial interventions offered to at-risk families with infants aged 0-12 months in Western Organisation for Economic Co-operation and Development (OECD) countries, (2) interventions with a minimum of three sessions and at least half of these delivered postnatally and (3) outcomes reported for child development or parent-child relationship. Sixteen studies were included. Meta-analyses were conducted on seven outcomes represented in 13 studies. Parenting interventions significantly improved child behaviour ( d =0.14; 95% CI 0.03 to 0.26), parent-child relationship ( d =0.44; 95% CI 0.09 to 0.80) and maternal sensitivity ( d =0.46; 95% CI 0.26 to 0.65) postintervention. There were no significant effects on cognitive development ( d= 0.13; 95% CI -0.08 to 0.41), internalising behaviour ( d= 0.16; 95% CI -0.03 to 0.33) or externalising behaviour ( d= 0.16; 95% CI -0.01 to 0.30) post-intervention. At long-term follow-up we found no significant effect on child behaviour ( d= 0.15; 95% CI -0.03 to 0.31). Interventions offered to at-risk families in the first year of the child's life appear to improve child behaviour, parent-child relationship and maternal sensitivity post-intervention, but not child cognitive

  12. Methological quality of systematic reviews and meta-analyses on acupuncture for stroke: A review of review.

    Science.gov (United States)

    Chen, Xin-Lin; Mo, Chuan-Wei; Lu, Li-Ya; Gao, Ri-Yang; Xu, Qian; Wu, Min-Feng; Zhou, Qian-Yi; Hu, Yue; Zhou, Xuan; Li, Xian-Tao

    2017-11-01

    To assess the methodological quality of systematic reviews and meta-analyses regarding acupuncture intervention for stroke and the primary studies within them. Two researchers searched PubMed, Cumulative index to Nursing and Allied Health Literature, Embase, ISI Web of Knowledge, Cochrane, Allied and Complementary Medicine, Ovid Medline, Chinese Biomedical Literature Database, China National Knowledge Infrastructure, Wanfang and Traditional Chinese Medical Database to identify systematic reviews and meta-analyses about acupuncture for stroke published from the inception to December 2016. Review characteristics and the criteria for assessing the primary studies within reviews were extracted. The methodological quality of the reviews was assessed using adapted Oxman and Guyatt Scale. The methodological quality of primary studies was also assessed. Thirty-two eligible reviews were identified, 15 in English and 17 in Chinese. The English reviews were scored higher than the Chinese reviews (P=0.025), especially in criteria for avoiding bias and the scope of search. All reviews used the quality criteria to evaluate the methodological quality of primary studies, but some criteria were not comprehensive. The primary studies, in particular the Chinese reviews, had problems with randomization, allocation concealment, blinding, dropouts and withdrawals, intent-to-treat analysis and adverse events. Important methodological flaws were found in Chinese systematic reviews and primary studies. It was necessary to improve the methodological quality and reporting quality of both the systematic reviews published in China and primary studies on acupuncture for stroke.

  13. Locomotor activity measures in the diagnosis of Attention Deficit Hyperactivity Disorder: Meta-analyses and new findings

    Science.gov (United States)

    Murillo, Lourdes García; Cortese, Samuele; Anderson, David; Martino, Adriana Di; Castellanos, Francisco Xavier

    2015-01-01

    Introduction Our aim was to assess differences in movement measures in Attention-Deficit/Hyperactivity Disorder (ADHD) vs. typically developing (TD) controls. Methods We performed meta-analyses of published studies on motion measures contrasting ADHD with controls. We also conducted a case-control study with children/adolescents (n=61 TD, n=62 ADHD) and adults (n=30 TD, n=19 ADHD) using the McLean Motion Activity Test, semi-structured diagnostic interviews and the Behavior Rating Inventory of Executive Function and Conners (Parent, Teacher; Self) Rating Scales. Results Meta-analyses revealed medium-to-large effect sizes for actigraph (standardized mean difference [SMD]: 0.64, 95% Confidence interval (CI): 0.43, 0.85) and motion tracking systems (SDM: 0.92, 95% CI: 0.65, 1.20) measures in differentiating individuals with ADHD from controls. Effects sizes were similar in studies of children/adolescents ([SMD]:0.75, 95% CI: 0.50, 1.01) and of adults ([SMD]: 0.73, 95% CI: 0.46, 1.00). In our sample, ADHD groups differed significantly in number of Head Movements (p=0.02 in children; p=0.002 in adults), Displacement (p=0.009/pADHD (d=0.45, 95% CI: 0.08, 0.82). In the concurrent go/no-go task, reaction time variability was significantly greater in ADHD (pADHD even in adults. Our results suggest that objective locomotion measures may be particularly useful in evaluating adults with possible ADHD. PMID:25770940

  14. [How Reliable are Meta-Analyses? An Appraisal Using the Example of Magnesium Tocolysis].

    Science.gov (United States)

    Czekelius, P; Wenzel, H

    2016-04-01

    Crowther et al. 3 analysed the effectivity of magnesium tocolysis in preventing preterm birth. They conclude that there is no evidence for protection. In its latest guidelines, based on this Cochrane analysis, the German Association of Gynaecology and Obstetrics (DGGG) does not recommend any more the use of magnesium for tocolysis. Magnesium tocolysis is said neither to delay nor to prevent preterm birth. Moreover, magnesium could be responsible for increased mortality in infants. These conclusions are mostly based on the research of Mittendorf et al. 4. In a Cochrane study from 2014, which in principal was identical to the study mentioned above 3, Crowther et al. 6 confirm the previous findings and conclusions. Having successfully applied magnesium tocolysis for many years, these surprising conclusions led us to review the soundness of the publications mentioned above. Combining the practical experience of many years with the results of a comprehensive literature retrieval, we finally contrasted this knowledge with the findings of the aforementioned publications that caused the DGGG to withdraw the recommendation for magnesium. To draw binding consequences from a meta-analysis is possible only when stringent quality guidelines are observed. The studies that were included in the Cochrane review of Crowther et al. 3 are very heterogeneous and are not suitable for concluding on poor or even lacking effectiveness of magnesium tocolysis. Furthermore, the cases of infant deaths, as stated by Mittendorf et al. 4, are very unlikely caused by magnesium. When including studies in a meta-analysis special attention has to be given to the relevance and unbiased selection of studies. To prevent any misjudgment, a thorough knowledge of the included studies seems essentiell. There is not sufficient evidence to withdraw the recommendation for applying magnesium tocolysis as a preventive measure to prevent preterm birth. In the sense of evidence-based medicine, long

  15. Cognitive dysfunction in bipolar disorder and schizophrenia: a systematic review of meta-analyses

    Directory of Open Access Journals (Sweden)

    Bortolato B

    2015-12-01

    Full Text Available Beatrice Bortolato,1 Kamilla W Miskowiak,2 Cristiano A Köhler,3 Eduard Vieta,4 André F Carvalho3 1Department of Mental Health, ULSS 10 “Veneto Orientale”, Venice, Italy; 2Psychiatric Centre Copenhagen, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark; 3Translational Psychiatry Research Group and Department of Clinical Medicine, Faculty of Medicine, Federal University of Ceará, Fortaleza, CE, Brazil; 4Bipolar Disorders Program, Institute of Neuroscience, Hospital Clínic Barcelona, IDIBAPS, CIBERSAM, University of Barcelona, Catalonia, Spain Abstract: Cognitive impairment is a core feature of schizophrenia (SZ and bipolar disorder (BD. A neurocognitive profile characterized by widespread cognitive deficits across multiple domains in the context of substantial intellectual impairment, which appears to antedate illness onset, is a replicated finding in SZ. There is no specific neuropsychological signature that can facilitate the diagnostic differentiation of SZ and BD, notwithstanding, neuropsychological deficits appear more severe in SZ. The literature in this field has provided contradictory results due to methodological differences across studies. Meta-analytic techniques may offer an opportunity to synthesize findings and to control for potential sources of heterogeneity. Here, we performed a systematic review of meta-analyses of neuropsychological findings in SZ and BD. While there is no conclusive evidence for progressive cognitive deterioration in either SZ or BD, some findings point to more severe cognitive deficits in patients with early illness onset across both disorders. A compromised pattern of cognitive functioning in individuals at familiar and/or clinical risk to psychosis as well as in first-degree relatives of BD patients suggests that early neurodevelopmental factors may play a role in the emergence of cognitive deficits in both disorders. Premorbid intellectual impairment in SZ and at least in a

  16. Age and sex as moderators of the placebo response – an evaluation of systematic reviews and meta-analyses across medicine.

    Science.gov (United States)

    Weimer, Katja; Colloca, Luana; Enck, Paul

    2015-01-01

    Predictors of the placebo response (PR) in randomized controlled trials (RCT) have been searched for ever since RCT have become the standard for testing novel therapies and age and gender are routinely documented data in all trials irrespective of the drug tested, its indication, and the primary and secondary end points chosen. To evaluate whether age and gender have been found to be reliable predictors of the PR across medical subspecialties, we extracted 75 systematic reviews, meta-analyses, and meta-regressions performed in major medical areas (neurology, psychiatry, internal medicine) known for high PR rates. The literature database used contains approximately 2,500 papers on various aspects of the genuine PR. These ‘meta-analyses’ were screened for statistical predictors of the PR across multiple RCT, including age and gender, but also other patient-based and design-based predictors of higher PR rates. Retrieved papers were sorted for areas and disease categories. Only 15 of the 75 analyses noted an effect of younger age to be associated with higher PR, and this was predominantly in psychiatric conditions but not in depression, and internal medicine but not in gastroenterology. Female gender was associated with higher PR in only 3 analyses. Among the patient-based predictors, the most frequently noted factor was lower symptom severity at baseline, and among the design- based factors, it was a randomization ratio that selected more patients to drugs than to placebo, more frequent study visits, and more recent trials that were associated with higher PR rates. While younger age may contribute to the PR in some conditions, sex does not. There is currently no evidence that the PR is different in the elderly. PR are, however, markedly influenced by the symptom severity at baseline, and by the likelihood of receiving active treatment in placebo- controlled trials. © 2014 S. Karger AG, Basel.

  17. Alcohol Consumption as a Risk Factor for Acute and Chronic Pancreatitis: A Systematic Review and a Series of Meta-analyses.

    Science.gov (United States)

    Samokhvalov, Andriy V; Rehm, Jürgen; Roerecke, Michael

    2015-12-01

    Pancreatitis is a highly prevalent medical condition associated with a spectrum of endocrine and exocrine pancreatic insufficiencies. While high alcohol consumption is an established risk factor for pancreatitis, its relationship with specific types of pancreatitis and a potential threshold have not been systematically examined. We conducted a systematic literature search for studies on the association between alcohol consumption and pancreatitis based on PRISMA guidelines. Non-linear and linear random-effect dose-response meta-analyses using restricted cubic spline meta-regressions and categorical meta-analyses in relation to abstainers were conducted. Seven studies with 157,026 participants and 3618 cases of pancreatitis were included into analyses. The dose-response relationship between average volume of alcohol consumption and risk of pancreatitis was monotonic with no evidence of non-linearity for chronic pancreatitis (CP) for both sexes (p = 0.091) and acute pancreatitis (AP) in men (p = 0.396); it was non-linear for AP in women (p = 0.008). Compared to abstention, there was a significant decrease in risk (RR = 0.76, 95%CI: 0.60-0.97) of AP in women below the threshold of 40 g/day. No such association was found in men (RR = 1.1, 95%CI: 0.69-1.74). The RR for CP at 100 g/day was 6.29 (95%CI: 3.04-13.02). The dose-response relationships between alcohol consumption and risk of pancreatitis were monotonic for CP and AP in men, and non-linear for AP in women. Alcohol consumption below 40 g/day was associated with reduced risk of AP in women. Alcohol consumption beyond this level was increasingly detrimental for any type of pancreatitis. The work was financially supported by a grant from the National Institute on Alcohol Abuse and Alcoholism (R21AA023521) to the last author.

  18. Lack of consensus on the role of endoscopic retrograde cholangiography in acute biliary pancreatitis in published meta-analyses and guidelines: a systematic review

    NARCIS (Netherlands)

    Geenen, E.J.M. van; Santvoort, H.C. van; Besselink, M.G.; Peet, D.L. van der; Erpecum, K.J. van; Fockens, P.; Mulder, C.J.; Bruno, M.J.

    2013-01-01

    OBJECTIVES: Several randomized controlled trials studied the role of endoscopic retrograde cholangiopancreaticography (ERCP) and endoscopic sphincterotomy (ES) in acute biliary pancreatitis (ABP). No study assessed whether these trials resulted in international consensus in published meta-analyses

  19. Lack of Consensus on the Role of Endoscopic Retrograde Cholangiography in Acute Biliary Pancreatitis in Published Meta-Analyses and Guidelines A Systematic Review

    NARCIS (Netherlands)

    van Geenen, Erwin-Jan M.; van Santvoort, Hjalmar C.; Besselink, Marc G. H.; van der Peet, Donald L.; van Erpecum, Karel J.; Fockens, Paul; Mulder, Chris J. J.; Bruno, Marco J.

    2013-01-01

    Objectives: Several randomized controlled trials studied the role of endoscopic retrograde cholangiopancreaticography (ERCP) and endoscopic sphincterotomy (ES) in acute biliary pancreatitis (ABP). No study assessed whether these trials resulted in international consensus in published meta-analyses

  20. The limited informativeness of meta-analyses and media effects

    NARCIS (Netherlands)

    Valkenburg, P.M.

    2015-01-01

    In this issue of Perspectives on Psychological Science, Christopher Ferguson reports on a meta-analysis examining the relationship between children’s video game use and several outcome variables, including aggression and attention deficit symptoms (Ferguson, 2015, this issue). In this commentary, I

  1. Meta-analyses of KIF6 Trp719Arg in coronary heart disease and statin therapeutic effect.

    Directory of Open Access Journals (Sweden)

    Ping Peng

    Full Text Available The goal of our study is to assess the contribution of KIF6 Trp719Arg to both the risk of CHD and the efficacy of statin therapy in CHD patients.Meta-analysis of 8 prospective studies among 77,400 Caucasians provides evidence that 719Arg increases the risk of CHD (P<0.001, HR = 1.27, 95% CI = 1.15-1.41. However, another meta-analysis of 7 case-control studies among 65,200 individuals fails to find a significant relationship between Trp719Arg and the risk of CHD (P = 0.642, OR = 1.02, 95% CI = 0.95-1.08. This suggests that the contribution of Trp719Arg to CHD varies in different ethnic groups. Additional meta-analysis also shows that statin therapy only benefit the vascular patients carry 719Arg allele (P<0.001, relative ratio (RR = 0.60, 95% CI = 0.54-0.67. To examine the role of this genetic variant in CHD risk in Han Chinese, we have conducted a case-control study with 289 CHD cases, 193 non-CHD controls, and 329 unrelated healthy volunteers as healthy controls. On post hoc analysis, significant allele frequency difference of 719Arg is observed between female CHD cases and female total controls under the dominant model (P = 0.04, χ(2 = 4.228, df = 1, odd ratio (OR = 1.979, 95% confidence interval (CI = 1.023-3.828. Similar trends are observed for post hoc analysis between female CHD cases and female healthy controls (dominant model: P = 0.04, χ(2 = 4.231, df = 1, OR = 2.015, 95% CI = 1.024-3.964. Non-genetic CHD risk factors are not controlled in these analyses.Our meta-analysis demonstrates the role of Trp719Arg of KIF6 gene in the risk of CHD in Caucasians. The meta-analysis also suggests the role of this variant in statin therapeutic response in vascular diseases. Our case-control study suggests that Trp719Arg of KIF6 gene is associated with CHD in female Han Chinese through a post hoc analysis.

  2. Systematic review and meta-analysis in cardiac surgery: a primer.

    Science.gov (United States)

    Yanagawa, Bobby; Tam, Derrick Y; Mazine, Amine; Tricco, Andrea C

    2018-03-01

    The purpose of this article is to review the strengths and weaknesses of systematic reviews and meta-analyses to inform our current understanding of cardiac surgery. A systematic review and meta-analysis of a focused topic can provide a quantitative estimate for the effect of a treatment intervention or exposure. In cardiac surgery, observational studies and small, single-center prospective trials provide most of the clinical outcomes that form the evidence base for patient management and guideline recommendations. As such, meta-analyses can be particularly valuable in synthesizing the literature for a particular focused surgical question. Since the year 2000, there are over 800 meta-analysis-related publications in our field. There are some limitations to this technique, including clinical, methodological and statistical heterogeneity, among other challenges. Despite these caveats, results of meta-analyses have been useful in forming treatment recommendations or in providing guidance in the design of future clinical trials. There is a growing number of meta-analyses in the field of cardiac surgery. Knowledge translation via meta-analyses will continue to guide and inform cardiac surgical practice and our practice guidelines.

  3. Leeftijd, het psychologisch contract en werkattitudes: een meta-analyse

    NARCIS (Netherlands)

    Bal, P. Matthijs; Lange, A.H. de; Jansen, P.G.W.; Velde, M.E.G. van der

    2010-01-01

    The meta-analysis investigated the relations between age and psychological contracts. It was expected that age would be positively related to the employer obligations, and that age would moderate the relations between contract breach and job attitudes. The hypotheses were tested by means of a

  4. Online open neuroimaging mass meta-analysis

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Kempton, Matthew J.; Williams, Steven C. R.

    We describe a system for meta-analysis where a wiki stores numerical data in a simple format and a web service performs the numerical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system allows for mass meta-analysis, e...

  5. Development of a combined database for meta-epidemiological research

    DEFF Research Database (Denmark)

    Savović, Jelena; Harris, Ross J; Wood, Lesley

    2010-01-01

    or review. Unique identifiers were assigned to each reference and used to identify duplicate trials. Sets of meta-analyses with overlapping trials were identified and duplicates removed. Overlapping trials were used to examine agreement between assessments of trial characteristics. The combined database...... database will be used to examine the combined evidence on sources of bias in randomized controlled trials. The strategy used to remove overlap between meta-analyses may be of use for future empirical research. Copyright © 2010 John Wiley & Sons, Ltd.......Collections of meta-analyses assembled in meta-epidemiological studies are used to study associations of trial characteristics with intervention effect estimates. However, methods and findings are not consistent across studies. To combine data from 10 meta-epidemiological studies into a single...

  6. Agreement between the results of meta-analyses from case reports and from clinical studies regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I who initiated enzyme replacement therapy in adult age: An example of case reports meta-analyses as an useful tool for evidence-based medicine in rare diseases.

    Science.gov (United States)

    Sampayo-Cordero, Miguel; Miguel-Huguet, Bernat; Pardo-Mateos, Almudena; Moltó-Abad, Marc; Muñoz-Delgado, Cecilia; Pérez-López, Jordi

    2018-02-01

    Case reports might have a prominent role in the rare diseases field, due to the small number of patients affected by one such disease. A previous systematic review regarding the efficacy of laronidase therapy in patients with mucopolysaccharidosis type I (MPS-I) who initiated enzyme replacement therapy (ERT) in adult age has been published. The review included a meta-analysis of 19 clinical studies and the description of eleven case reports. It was of interest to perform a meta-analysis of those case reports to explore the role of such meta-analyses as a tool for evidence-based medicine in rare diseases. The study included all case reports with standard treatment regimen. Primary analysis was the percentage of case reports showing an improvement in a specific outcome. Only when that percentage was statistically higher than 5%, the improvement was confirmed as such. The outcomes that accomplished this criterion were ranked and compared to the GRADE criteria obtained by those same outcomes in the previous meta-analysis of clinical studies. There were three outcomes that had a significant improvement: Urine glycosaminoglycans, liver volume and 6-minute walking test. Positive and negative predictive values, sensitivity and specificity for the results of the meta-analysis of case reports as compared to that of clinical studies were 100%, 88.9%, 75% and 100%, respectively. Accordingly, absolute (Rho=0.82, 95%CI: 0.47 to 0.95) and relative agreement (Kappa=0.79, 95%CI: 0.593 to 0.99) between the number of case reports with improvement in a specific outcome and the GRADE evidence score for that outcome were good. Sensitivity analysis showed that agreement between the meta-analysis of case reports and that of the clinical studies were good only when using a strong confirmatory strategy for outcome improvement in case reports. We found an agreement between the results of meta-analyses from case reports and from clinical studies in the efficacy of laronidase therapy in

  7. The effect of grinding on the mechanical behavior of Y-TZP ceramics: A systematic review and meta-analyses.

    Science.gov (United States)

    Pereira, G K R; Fraga, S; Montagner, A F; Soares, F Z M; Kleverlaan, C J; Valandro, L F

    2016-10-01

    The aim of this study was to systematically review the literature to assess the effect of grinding on the mechanical properties, structural stability and superficial characteristics of Y-TZP ceramics. The MEDLINE via PubMed and Web of Science (ISI - Web of Knowledge) electronic databases were searched with included peer-reviewed publications in English language and with no publication year limit. From 342 potentially eligible studies, 73 were selected for full-text analysis, 30 were included in the systematic review with 20 considered in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Statistical analyses were performed using RevMan 5.1, with random effects model, at a significance level of 0.05. A descriptive analysis considering phase transformation, Y-TZP grain size, Vickers hardness, residual stress and aging of all included studies were executed. Four outcomes were considered in the meta-analyses (factor: grinding x as-sintered) in global and subgroups analyses (grinding tool, grit-size and cooling) for flexural strength and roughness (Ra) data. A significant difference (pgrinding; subgroup analyses revealed that different parameters also lead to different effects on roughness. High heterogeneity was found in some comparisons. Generally grinding promotes decrease in strength and increase in roughness of Y-TZP ceramics. However, the use of a grinding tool that allows greater accuracy of the movement (i.e. contra angle hand-pieces coupled to slowspeed turbines), small grit size (<50μm) and the use of plenty coolant seem to be the main factors to decrease the defect introduction and allow the occurrence of the toughening transformation mechanism, decreasing the risk of deleterious impact on Y-TZP mechanical properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. STRUCTURE OF RUSSIAN PUBLICATIONS IN CLINICAL IMMUNOLOGY AND ALLERGOLOGY (JOURNAL ARTICLES, CLINICAL TRIALS, META-ANALYSES AND PRACTICE GUIDELINES IN COMPARISON WITH OTHER BRICS COUNTRIES IN 2008-2015

    Directory of Open Access Journals (Sweden)

    L. I. Lugacheva

    2018-01-01

    Full Text Available It is obvious that any evolving scientific medical field is a dynamic system that cannot stay at the stage of accumulation of primary information, and inevitably goes to the stages of clinical trials, generalization of information in meta-analyses and completes the study by creation of practical guidelines. The purpose of this study was a quantitative analysis of publicly available data in the field of clinical immunology in Russia during 2008-2015, identifying the ratios of clinical trials, meta-analyses, and practical guidelines, as well as evaluating the results by comparison with other BRICS countries. Study design was performed by retrospective bibliometric methods. It is revealed, that, in Russia, 16 clinical trials, 3 meta-analyses and 1 practice guideline were issued per 1000 original journal articles. Accordingly in the People’s Republic of China this ratios have made 34/25/4; in Federal Republic of Brazil, 42/87/7; in Republic of India, 76/58/34, and in Republic of Southern Africa, 134/43/36. Moreover, we have obtained evidence which suggests optimistic prospectives for scientific clinical immunology in Russia. 

  9. Visible learning a synthesis of over 800 meta-analyses relating to achievement

    CERN Document Server

    Hattie, John A C

    2009-01-01

    This unique and ground-breaking book is the result of 15 years research and synthesises over 800 meta-analyses on the influences on achievement in school-aged students. It builds a story about the power of teachers, feedback, and a model of learning and understanding. The research involves many millions of students and represents the largest ever evidence based research into what actually works in schools to improve learning. Areas covered include the influence of the student, home, school, curricula, teacher, and teaching strategies. A model of teaching and learning is developed based on the notion of visible teaching and visible learning. A major message is that what works best for students is similar to what works best for teachers - an attention to setting challenging learning intentions, being clear about what success means, and an attention to learning strategies for developing conceptual understanding about what teachers and students know and understand. Although the current evidence based fad has turn...

  10. Introduction, comparison, and validation of Meta-Essentials: A free and simple tool for meta-analysis.

    Science.gov (United States)

    Suurmond, Robert; van Rhee, Henk; Hak, Tony

    2017-12-01

    We present a new tool for meta-analysis, Meta-Essentials, which is free of charge and easy to use. In this paper, we introduce the tool and compare its features to other tools for meta-analysis. We also provide detailed information on the validation of the tool. Although free of charge and simple, Meta-Essentials automatically calculates effect sizes from a wide range of statistics and can be used for a wide range of meta-analysis applications, including subgroup analysis, moderator analysis, and publication bias analyses. The confidence interval of the overall effect is automatically based on the Knapp-Hartung adjustment of the DerSimonian-Laird estimator. However, more advanced meta-analysis methods such as meta-analytical structural equation modelling and meta-regression with multiple covariates are not available. In summary, Meta-Essentials may prove a valuable resource for meta-analysts, including researchers, teachers, and students. © 2017 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd.

  11. Rethinking Meta-Analysis: Applications for Air Pollution Data and Beyond

    Science.gov (United States)

    Goodman, Julie E; Petito Boyce, Catherine; Sax, Sonja N; Beyer, Leslie A; Prueitt, Robyn L

    2015-01-01

    Meta-analyses offer a rigorous and transparent systematic framework for synthesizing data that can be used for a wide range of research areas, study designs, and data types. Both the outcome of meta-analyses and the meta-analysis process itself can yield useful insights for answering scientific questions and making policy decisions. Development of the National Ambient Air Quality Standards illustrates many potential applications of meta-analysis. These applications demonstrate the strengths and limitations of meta-analysis, issues that arise in various data realms, how meta-analysis design choices can influence interpretation of results, and how meta-analysis can be used to address bias and heterogeneity. Reviewing available data from a meta-analysis perspective can provide a useful framework and impetus for identifying and refining strategies for future research. Moreover, increased pervasiveness of a meta-analysis mindset—focusing on how the pieces of the research puzzle fit together—would benefit scientific research and data syntheses regardless of whether or not a quantitative meta-analysis is undertaken. While an individual meta-analysis can only synthesize studies addressing the same research question, the results of separate meta-analyses can be combined to address a question encompassing multiple data types. This observation applies to any scientific or policy area where information from a variety of disciplines must be considered to address a broader research question. PMID:25969128

  12. Evidence from Meta-Analyses of the Facial Width-to-Height Ratio as an Evolved Cue of Threat.

    Directory of Open Access Journals (Sweden)

    Shawn N Geniole

    Full Text Available The facial width-to-height ratio (FWHR is the width of the face divided by the height of the upper face. There is mixed evidence for the hypothesis that the FWHR is a cue of threat and dominance in the human face. We conducted a systematic review and meta-analyses of all peer-reviewed studies (and 2 unpublished studies to estimate the magnitude of the sex difference in the FWHR, and the magnitude of the relationship between the FWHR and threatening and dominant behaviours and perceptions. Studies were eligible for inclusion if the authors reported an analysis involving the FWHR. Our analyses revealed that the FWHR was larger in men than in women (d = .11, n = 10,853, cued judgements of masculinity in men (r = .35, n of faces = 487; n of observers = 339, and was related to body mass index (r = .31, n = 2,506. Further, the FWHR predicted both threat behaviour in men (r = .16, n = 4,603 and dominance behaviour in both sexes (r = .12, n = 948 across a variety of indices. Individuals with larger FWHRs were judged by observers as more threatening (r = .46, n of faces = 1,691; n of observers = 2,076 and more dominant (r = .20, n of faces = 603; n of observers = 236 than those with smaller FWHRs. Individuals with larger FWHRs were also judged as less attractive (r = -.26, n of faces = 721; n of observers = 335, especially when women made the judgements. These findings provide some support for the hypothesis that the FWHR is part of an evolved cueing system of intra-sexual threat and dominance in men. A limitation of the meta-analyses on perceptions of threat and dominance were the low number of stimuli involving female and older adult faces.

  13. Maternal Colonization With Group B Streptococcus and Serotype Distribution Worldwide: Systematic Review and Meta-analyses.

    Science.gov (United States)

    Russell, Neal J; Seale, Anna C; O'Driscoll, Megan; O'Sullivan, Catherine; Bianchi-Jassir, Fiorella; Gonzalez-Guarin, Juan; Lawn, Joy E; Baker, Carol J; Bartlett, Linda; Cutland, Clare; Gravett, Michael G; Heath, Paul T; Le Doare, Kirsty; Madhi, Shabir A; Rubens, Craig E; Schrag, Stephanie; Sobanjo-Ter Meulen, Ajoke; Vekemans, Johan; Saha, Samir K; Ip, Margaret

    2017-11-06

    Maternal rectovaginal colonization with group B Streptococcus (GBS) is the most common pathway for GBS disease in mother, fetus, and newborn. This article, the second in a series estimating the burden of GBS, aims to determine the prevalence and serotype distribution of GBS colonizing pregnant women worldwide. We conducted systematic literature reviews (PubMed/Medline, Embase, Latin American and Caribbean Health Sciences Literature [LILACS], World Health Organization Library Information System [WHOLIS], and Scopus), organized Chinese language searches, and sought unpublished data from investigator groups. We applied broad inclusion criteria to maximize data inputs, particularly from low- and middle-income contexts, and then applied new meta-analyses to adjust for studies with less-sensitive sampling and laboratory techniques. We undertook meta-analyses to derive pooled estimates of maternal GBS colonization prevalence at national and regional levels. The dataset regarding colonization included 390 articles, 85 countries, and a total of 299924 pregnant women. Our adjusted estimate for maternal GBS colonization worldwide was 18% (95% confidence interval [CI], 17%-19%), with regional variation (11%-35%), and lower prevalence in Southern Asia (12.5% [95% CI, 10%-15%]) and Eastern Asia (11% [95% CI, 10%-12%]). Bacterial serotypes I-V account for 98% of identified colonizing GBS isolates worldwide. Serotype III, associated with invasive disease, accounts for 25% (95% CI, 23%-28%), but is less frequent in some South American and Asian countries. Serotypes VI-IX are more common in Asia. GBS colonizes pregnant women worldwide, but prevalence and serotype distribution vary, even after adjusting for laboratory methods. Lower GBS maternal colonization prevalence, with less serotype III, may help to explain lower GBS disease incidence in regions such as Asia. High prevalence worldwide, and more serotype data, are relevant to prevention efforts. © The Author 2017. Published by

  14. Systematic review and meta-analyses of tranexamic acid use for bleeding reduction in prostate surgery.

    Science.gov (United States)

    Longo, Marcelo A; Cavalheiro, Bárbara T; de Oliveira Filho, Getúlio R

    2018-05-01

    Prostate cancer and benign prostatic hyperplasia have an increased incidence with aging. The most effective treatments are radical prostatectomy and transurethral resection of the prostate. To reduce perioperative bleeding in these surgeries, an approach is the use of tranexamic acid (TXA). Studies show that TXA is effective in reducing the blood loss and the need for transfusion in cardiac, orthopedic, and gynecological surgeries. In prostate surgeries, its efficacy and safety have not been established yet. To determine whether there are differences between TXA versus placebo in terms of intraoperative blood loss, transfusion requirements, hemoglobin levels and the incidence of thromboembolic events. Systematic review with meta-analyses. Anesthesia for prostate surgery. We searched the Medline, Cochrane, EBSCO, and Web of Science databases up to 2017 for randomized controlled trials that compared TXA administration with a control group in patients who submitted to prostate surgery. The primary outcomes were the intraoperative blood loss and transfusion rate. Data on hemoglobin levels and the incidence of deep vein thrombosis (DVT) and pulmonary embolism (PE) were also collected. Nine comparative studies were included in the meta-analyses. The estimated blood loss and transfusion rate were lower in patients receiving TXA, with a standardized mean difference of -1.93 (95% CI = -2.81 to -1.05, I 2  = 96%), and a risk ratio of 0.61 (95% CI = 0.47 to 0.80, I 2  = 0%), respectively. The hemoglobin levels and the incidence of DVT and PE did not differ between the groups. TXA reduced intraoperative blood loss and the need for transfusion, without increasing the risk of DVT and PE in prostate surgeries. Due to the limited number of studies and the high heterogeneity of the results, more clinical trials with a large number of patients are necessary to confirm these findings. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. A systematic review and meta-Analyses show that carbapenem use and medical devices are the leading risk factors for carbapenem- resistant pseudomonas aeruginosa

    NARCIS (Netherlands)

    A.F. Voor (Anne); J.A. Severin (Juliëtte); E.M.E.H. Lesaffre (Emmanuel); M.C. Vos (Margreet)

    2014-01-01

    textabstractA systematic review and meta-Analyses were performed to identify the risk factors associated with carbapenem-resistant Pseudomonas aeruginosa and to identify sources and reservoirs for the pathogen. A systematic search of PubMed and Embase databases from 1 January 1987 until 27 January

  16. Are we hammering square pegs into round holes? An investigation of the meta-analyses of reading research with students who are d/Deaf or hard of hearing and students who are hearing.

    Science.gov (United States)

    Wang, Ye; Williams, Cheri

    2014-01-01

    In a qualitative meta-analysis, the researchers systematically reviewed qualitative and quantitative meta-analyses on reading research with PK-12 students published after the 2000 National Reading Panel (NRP) report. Eleven qualitative and 39 quantitative meta-analyses were reviewed examining reading research with typically developing hearing students, special education hearing students (including English Language Learners), and d/Deaf or hard of hearing (d/Dhh) students. Generally, the meta-analysis yielded findings similar to and corroborative of the NRP's. Contradictory results (e.g., regarding the role of rhyme awareness in reading outcomes) most often resulted from differing definitions of interventions and their measurements. The analysis provided evidence of several instructional approaches that support reading development. On the basis of the qualitative similarity hypothesis (Paul, 2010, 2012; Paul & Lee, 2010; Paul & Wang, 2012; Paul, Wang, & Williams, 2013), the researchers argue that these instructional strategies also should effectively support d/Dhh children's reading development.

  17. Meta-Analysis at Middle Age: A Personal History

    Science.gov (United States)

    Glass, Gene V.

    2015-01-01

    The 40-year history of meta-analysis is traced from the vantage point of one of its originators. Research syntheses leading to the first examples of meta-analysis are identified. Early meta-analyses of the literature on psychotherapy outcomes and school class size are recounted. The influence on the development of meta-analysis of several…

  18. Evaluation of European Schizophrenia GWAS Loci in Asian Populations via Comprehensive Meta-Analyses.

    Science.gov (United States)

    Xiao, Xiao; Luo, Xiong-Jian; Chang, Hong; Liu, Zichao; Li, Ming

    2017-08-01

    Schizophrenia is a severe and highly heritable neuropsychiatric disorder. Recent genetic analyses including genome-wide association studies (GWAS) have implicated multiple genome-wide significant variants for schizophrenia among European populations. However, many of these risk variants were not largely validated in other populations of different ancestry such as Asians. To validate whether these European GWAS significant loci are associated with schizophrenia in Asian populations, we conducted a systematic literature search and meta-analyses on 19 single nucleotide polymorphisms (SNPs) in Asian populations by combining all available case-control and family-based samples, including up to 30,000 individuals. We employed classical fixed (or random) effects inverse variance weighted methods to calculate summary odds ratios (ORs) and 95 % confidence intervals (CIs). Among the 19 GWAS loci, we replicated the risk associations of nine markers (e.g., SNPs at VRK2, ITIH3/4, NDST3, NOTCH4) surpassing significance level (two-tailed P Asian replication samples and initial European GWAS findings, and the successful replications of these GWAS loci in a different ethnic group provide stronger evidence for their clinical associations with schizophrenia. Further studies, focusing on the molecular mechanisms of these GWAS significant loci, will become increasingly important for understanding of the pathogenesis to schizophrenia.

  19. RAMESES publication standards: meta-narrative reviews

    Directory of Open Access Journals (Sweden)

    Wong Geoff

    2013-01-01

    Full Text Available Abstract Background Meta-narrative review is one of an emerging menu of new approaches to qualitative and mixed-method systematic review. A meta-narrative review seeks to illuminate a heterogeneous topic area by highlighting the contrasting and complementary ways in which researchers have studied the same or a similar topic. No previous publication standards exist for the reporting of meta-narrative reviews. This publication standard was developed as part of the RAMESES (Realist And MEta-narrative Evidence Syntheses: Evolving Standards project. The project's aim is to produce preliminary publication standards for meta-narrative reviews. Methods We (a collated and summarized existing literature on the principles of good practice in meta-narrative reviews; (b considered the extent to which these principles had been followed by published reviews, thereby identifying how rigor may be lost and how existing methods could be improved; (c used a three-round online Delphi method with an interdisciplinary panel of national and international experts in evidence synthesis, meta-narrative reviews, policy and/or publishing to produce and iteratively refine a draft set of methodological steps and publication standards; (d provided real-time support to ongoing meta-narrative reviews and the open-access RAMESES online discussion list so as to capture problems and questions as they arose; and (e synthesized expert input, evidence review and real-time problem analysis into a definitive set of standards. Results We identified nine published meta-narrative reviews, provided real-time support to four ongoing reviews and captured questions raised in the RAMESES discussion list. Through analysis and discussion within the project team, we summarized the published literature, and common questions and challenges into briefing materials for the Delphi panel, comprising 33 members. Within three rounds this panel had reached consensus on 20 key publication standards, with an

  20. Trial Sequential Analysis in systematic reviews with meta-analysis

    Directory of Open Access Journals (Sweden)

    Jørn Wetterslev

    2017-03-01

    Full Text Available Abstract Background Most meta-analyses in systematic reviews, including Cochrane ones, do not have sufficient statistical power to detect or refute even large intervention effects. This is why a meta-analysis ought to be regarded as an interim analysis on its way towards a required information size. The results of the meta-analyses should relate the total number of randomised participants to the estimated required meta-analytic information size accounting for statistical diversity. When the number of participants and the corresponding number of trials in a meta-analysis are insufficient, the use of the traditional 95% confidence interval or the 5% statistical significance threshold will lead to too many false positive conclusions (type I errors and too many false negative conclusions (type II errors. Methods We developed a methodology for interpreting meta-analysis results, using generally accepted, valid evidence on how to adjust thresholds for significance in randomised clinical trials when the required sample size has not been reached. Results The Lan-DeMets trial sequential monitoring boundaries in Trial Sequential Analysis offer adjusted confidence intervals and restricted thresholds for statistical significance when the diversity-adjusted required information size and the corresponding number of required trials for the meta-analysis have not been reached. Trial Sequential Analysis provides a frequentistic approach to control both type I and type II errors. We define the required information size and the corresponding number of required trials in a meta-analysis and the diversity (D2 measure of heterogeneity. We explain the reasons for using Trial Sequential Analysis of meta-analysis when the actual information size fails to reach the required information size. We present examples drawn from traditional meta-analyses using unadjusted naïve 95% confidence intervals and 5% thresholds for statistical significance. Spurious conclusions in

  1. META-ANALYSIS: THE WAY FORWARD IN MEDICAL DISCOVERY

    African Journals Online (AJOL)

    data, and (6) report the results. Define the Research Question. A meta-analysis begins with a question. Common questions addressed in meta-analyses are whether one. META-ANALYSIS: THE WAY FORWARD IN MEDICAL DISCOVERY. Akinyemi J.O. MSc (Medical Statistics), B Tech (Comp. Sc.) Correspondence:.

  2. No evidence for genome-wide interactions on plasma fibrinogen by smoking, alcohol consumption and body mass index: results from meta-analyses of 80,607 subjects.

    Directory of Open Access Journals (Sweden)

    Jens Baumert

    Full Text Available Plasma fibrinogen is an acute phase protein playing an important role in the blood coagulation cascade having strong associations with smoking, alcohol consumption and body mass index (BMI. Genome-wide association studies (GWAS have identified a variety of gene regions associated with elevated plasma fibrinogen concentrations. However, little is yet known about how associations between environmental factors and fibrinogen might be modified by genetic variation. Therefore, we conducted large-scale meta-analyses of genome-wide interaction studies to identify possible interactions of genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentration. The present study included 80,607 subjects of European ancestry from 22 studies. Genome-wide interaction analyses were performed separately in each study for about 2.6 million single nucleotide polymorphisms (SNPs across the 22 autosomal chromosomes. For each SNP and risk factor, we performed a linear regression under an additive genetic model including an interaction term between SNP and risk factor. Interaction estimates were meta-analysed using a fixed-effects model. No genome-wide significant interaction with smoking status, alcohol consumption or BMI was observed in the meta-analyses. The most suggestive interaction was found for smoking and rs10519203, located in the LOC123688 region on chromosome 15, with a p value of 6.2 × 10(-8. This large genome-wide interaction study including 80,607 participants found no strong evidence of interaction between genetic variants and smoking status, alcohol consumption or BMI on fibrinogen concentrations. Further studies are needed to yield deeper insight in the interplay between environmental factors and gene variants on the regulation of fibrinogen concentrations.

  3. Phylogenomic analyses data of the avian phylogenomics project

    DEFF Research Database (Denmark)

    Jarvis, Erich D; Mirarab, Siavash; Aberer, Andre J

    2015-01-01

    BACKGROUND: Determining the evolutionary relationships among the major lineages of extant birds has been one of the biggest challenges in systematic biology. To address this challenge, we assembled or collected the genomes of 48 avian species spanning most orders of birds, including all Neognathae...... and two of the five Palaeognathae orders. We used these genomes to construct a genome-scale avian phylogenetic tree and perform comparative genomic analyses. FINDINGS: Here we present the datasets associated with the phylogenomic analyses, which include sequence alignment files consisting of nucleotides......ML algorithm or when using statistical binning with the coalescence-based MP-EST algorithm (which we refer to as MP-EST*). Other data sets, such as the coding sequence of some exons, revealed other properties of genome evolution, namely convergence. CONCLUSIONS: The Avian Phylogenomics Project is the largest...

  4. Making evidence more wanted: a systematic review of facilitators to enhance the uptake of evidence from systematic reviews and meta-analyses.

    Science.gov (United States)

    Wallace, John; Byrne, Charles; Clarke, Mike

    2012-12-01

    The increased uptake of evidence from systematic reviews is advocated because of their potential to improve the quality of decision making for patient care. Systematic reviews can do this by decreasing inappropriate clinical variation and quickly expediting the application of current, effective advances to everyday practice. However, research suggests that evidence from systematic reviews has not been widely adopted by health professionals. Little is known about the facilitators to uptake of research evidence from systematic reviews and meta-analyses. To review the facilitators to the uptake by decision makers, of evidence from systematic, meta-analyses and the databases containing them. We searched 19 databases covering the full range of publication years, utilised three search engines and also personally contacted investigators. Grey literature and knowledge translation research was particularly sought. Reference lists of primary studies and related reviews were also searched. Studies were included if they reported on the views and perceptions of decision makers on the uptake of evidence from systematic reviews, meta-analyses and the databases associated with them. One investigator screened titles to identify candidate articles, and then two reviewers independently assessed the relevance of retrieved articles to exclude studies that did not meet the inclusion criteria. Quality of the included studies was also assessed. Using a pre-established taxonomy, two reviewers described the methods of included studies and extracted data that were summarised in tables and then analysed. Differences were resolved by consensus. Of articles initially identified, we selected unique published studies describing at least one facilitator to the uptake of evidence from systematic reviews. The 15 unique studies reported 10 surveys, three qualitative investigations and two mixed studies that addressed potential facilitators. Five studies were from Canada, four from the UK, three from

  5. A systematic review, and meta-analyses, of the impact of health-related claims on dietary choices.

    Science.gov (United States)

    Kaur, Asha; Scarborough, Peter; Rayner, Mike

    2017-07-11

    Health-related claims are statements regarding the nutritional content of a food (nutrition claims) and/or indicate that a relationship exists between a food and a health outcome (health claims). Their impact on food purchasing or consumption decisions is unclear. This systematic review measured the effect of health-related claims, on pre-packaged foods in retail settings, on adult purchasing decisions (real and perceived). In September 2016, we searched MEDLINE, EMBASE, PsychINFO, CAB abstracts, Business Source Complete, and Web of Science/Science Citation Index & Social Science Citation Index for articles in English published in peer-review journals. Studies were included if they were controlled experiments where the experimental group(s) included a health-related claim and the control group involved an identical product without a health-related claim. Included studies measured (at an individual or population level); actual or intended choice, purchases, and/or consumption. The primary outcome was product choices and purchases, the secondary outcome was food consumption and preference. Results were standardised through calculating odds ratios and 95% confidence intervals (CI) for the likelihood of choosing a product when a health-related claim was present. Results were combined in a random-effects meta-analysis. Thirty-one papers were identified, 17 of which were included for meta-analyses. Most studies were conducted in Europe (n = 17) and the USA (n = 7). Identified studies were choice experiments that measured the likelihood of a product being chosen when a claim was present compared to when a claim was not present, (n = 16), 15 studies were experiments that measured either; intent-rating scale outcomes (n = 8), consumption (n = 6), a combination of the two (n = 1), or purchase data (n = 1). Overall, 20 studies found that claims increase purchasing and/or consumption, eight studies had mixed results, and two studies found consumption

  6. Genome-Wide Meta-Analyses of Breast, Ovarian, and Prostate Cancer Association Studies Identify Multiple New Susceptibility Loci Shared by at Least Two Cancer Types

    DEFF Research Database (Denmark)

    Kar, Siddhartha P; Beesley, Jonathan; Amin Al Olama, Ali

    2016-01-01

    UNLABELLED: Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis, but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112...... (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell......-type-specific expression quantitative trait locus and enhancer-gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P cancer meta-analysis. SIGNIFICANCE...

  7. Comprehensive review of genetic association studies and meta-analyses on miRNA polymorphisms and cancer risk.

    Directory of Open Access Journals (Sweden)

    Kshitij Srivastava

    Full Text Available MicroRNAs (miRNAs are small RNA molecules that regulate the expression of corresponding messenger RNAs (mRNAs. Variations in the level of expression of distinct miRNAs have been observed in the genesis, progression and prognosis of multiple human malignancies. The present study was aimed to investigate the association between four highly studied miRNA polymorphisms (mir-146a rs2910164, mir-196a2 rs11614913, mir-149 rs2292832 and mir-499 rs3746444 and cancer risk by using a two-sided meta-analytic approach.An updated meta-analysis based on 53 independent case-control studies consisting of 27573 cancer cases and 34791 controls was performed. Odds ratio (OR and 95% confidence interval (95% CI were used to investigate the strength of the association.Overall, the pooled analysis showed that mir-196a2 rs11614913 was associated with a decreased cancer risk (OR = 0.846, P = 0.004, TT vs. CC while other miRNA SNPs showed no association with overall cancer risk. Subgroup analyses based on type of cancer and ethnicity were also performed, and results indicated that there was a strong association between miR-146a rs2910164 and overall cancer risk in Caucasian population under recessive model (OR = 1.274, 95%CI = 1.096-1.481, P = 0.002. Stratified analysis by cancer type also associated mir-196a2 rs11614913 with lung and colorectal cancer at allelic and genotypic level.The present meta-analysis suggests an important role of mir-196a2 rs11614913 polymorphism with overall cancer risk especially in Asian population. Further studies with large sample size are needed to evaluate and confirm this association.

  8. Examining the associations between HIV-related stigma and health outcomes in people living with HIV/AIDS: a series of meta-analyses

    Science.gov (United States)

    Mitra, Sanjana; Chen, Shiyi; Gogolishvili, David; Globerman, Jason; Chambers, Lori; Wilson, Mike; Logie, Carmen H; Shi, Qiyun; Morassaei, Sara; Rourke, Sean B

    2016-01-01

    Objective To conduct a systematic review and series of meta-analyses on the association between HIV-related stigma and health among people living with HIV. Data sources A structured search was conducted on 6 electronic databases for journal articles reporting associations between HIV-related stigma and health-related outcomes published between 1996 and 2013. Study eligibility criteria Controlled studies, cohort studies, case-control studies and cross-sectional studies in people living with HIV were considered for inclusion. Outcome measures Mental health (depressive symptoms, emotional and mental distress, anxiety), quality of life, physical health, social support, adherence to antiretroviral therapy, access to and usage of health/social services and risk behaviours. Results 64 studies were included in our meta-analyses. We found significant associations between HIV-related stigma and higher rates of depression, lower social support and lower levels of adherence to antiretroviral medications and access to and usage of health and social services. Weaker relationships were observed between HIV-related stigma and anxiety, quality of life, physical health, emotional and mental distress and sexual risk practices. While risk of bias assessments revealed overall good quality related to how HIV stigma and health outcomes were measured on the included studies, high risk of bias among individual studies was observed in terms of appropriate control for potential confounders. Additional research should focus on elucidating the mechanisms behind the negative relationship between stigma and health to better inform interventions to reduce the impact of stigma on the health and well-being of people with HIV. Conclusions This systematic review and series of meta-analyses support the notion that HIV-related stigma has a detrimental impact on a variety of health-related outcomes in people with HIV. This review can inform the development of multifaceted, intersectoral interventions to

  9. Examining the associations between HIV-related stigma and health outcomes in people living with HIV/AIDS: a series of meta-analyses.

    Science.gov (United States)

    Rueda, Sergio; Mitra, Sanjana; Chen, Shiyi; Gogolishvili, David; Globerman, Jason; Chambers, Lori; Wilson, Mike; Logie, Carmen H; Shi, Qiyun; Morassaei, Sara; Rourke, Sean B

    2016-07-13

    To conduct a systematic review and series of meta-analyses on the association between HIV-related stigma and health among people living with HIV. A structured search was conducted on 6 electronic databases for journal articles reporting associations between HIV-related stigma and health-related outcomes published between 1996 and 2013. Controlled studies, cohort studies, case-control studies and cross-sectional studies in people living with HIV were considered for inclusion. Mental health (depressive symptoms, emotional and mental distress, anxiety), quality of life, physical health, social support, adherence to antiretroviral therapy, access to and usage of health/social services and risk behaviours. 64 studies were included in our meta-analyses. We found significant associations between HIV-related stigma and higher rates of depression, lower social support and lower levels of adherence to antiretroviral medications and access to and usage of health and social services. Weaker relationships were observed between HIV-related stigma and anxiety, quality of life, physical health, emotional and mental distress and sexual risk practices. While risk of bias assessments revealed overall good quality related to how HIV stigma and health outcomes were measured on the included studies, high risk of bias among individual studies was observed in terms of appropriate control for potential confounders. Additional research should focus on elucidating the mechanisms behind the negative relationship between stigma and health to better inform interventions to reduce the impact of stigma on the health and well-being of people with HIV. This systematic review and series of meta-analyses support the notion that HIV-related stigma has a detrimental impact on a variety of health-related outcomes in people with HIV. This review can inform the development of multifaceted, intersectoral interventions to reduce the impact of HIV-related stigma on the health and well-being of people living

  10. Cancer and central nervous system disorders: protocol for an umbrella review of systematic reviews and updated meta-analyses of observational studies.

    Science.gov (United States)

    Catalá-López, Ferrán; Hutton, Brian; Driver, Jane A; Page, Matthew J; Ridao, Manuel; Valderas, José M; Alonso-Arroyo, Adolfo; Forés-Martos, Jaume; Martínez, Salvador; Gènova-Maleras, Ricard; Macías-Saint-Gerons, Diego; Crespo-Facorro, Benedicto; Vieta, Eduard; Valencia, Alfonso; Tabarés-Seisdedos, Rafael

    2017-04-04

    The objective of this study will be to synthesize the epidemiological evidence and evaluate the validity of the associations between central nervous system disorders and the risk of developing or dying from cancer. We will perform an umbrella review of systematic reviews and conduct updated meta-analyses of observational studies (cohort and case-control) investigating the association between central nervous system disorders and the risk of developing or dying from any cancer or specific types of cancer. Searches involving PubMed/MEDLINE, EMBASE, SCOPUS and Web of Science will be used to identify systematic reviews and meta-analyses of observational studies. In addition, online databases will be checked for observational studies published outside the time frames of previous reviews. Eligible central nervous system disorders will be Alzheimer's disease, anorexia nervosa, amyotrophic lateral sclerosis, autism spectrum disorders, bipolar disorder, depression, Down's syndrome, epilepsy, Huntington's disease, multiple sclerosis, Parkinson's disease and schizophrenia. The primary outcomes will be cancer incidence and cancer mortality in association with a central nervous system disorder. Secondary outcome measures will be site-specific cancer incidence and mortality, respectively. Two reviewers will independently screen references identified by the literature search, as well as potentially relevant full-text articles. Data will be abstracted, and study quality/risk of bias will be appraised by two reviewers independently. Conflicts at all levels of screening and abstraction will be resolved through discussion. Random-effects meta-analyses of primary observational studies will be conducted where appropriate. Parameters for exploring statistical heterogeneity are pre-specified. The World Cancer Research Fund (WCRF)/American Institute for Cancer Research (AICR) criteria and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach will be used

  11. Individual participant data meta-analysis of prognostic factor studies: state of the art?

    Directory of Open Access Journals (Sweden)

    Abo-Zaid Ghada

    2012-04-01

    examined; and important methodological details and summary results are often inadequately reported. Conclusions IPD meta-analyses of prognostic factors are achievable and offer many advantages, as displayed most expertly by the IMPACT initiative. However such projects face numerous logistical and methodological obstacles, and their conduct and reporting can often be substantially improved.

  12. Project analysis and integration economic analyses summary

    Science.gov (United States)

    Macomber, H. L.

    1986-01-01

    An economic-analysis summary was presented for the manufacture of crystalline-silicon modules involving silicon ingot/sheet, growth, slicing, cell manufacture, and module assembly. Economic analyses provided: useful quantitative aspects for complex decision-making to the Flat-plate Solar Array (FSA) Project; yardsticks for design and performance to industry; and demonstration of how to evaluate and understand the worth of research and development both to JPL and other government agencies and programs. It was concluded that future research and development funds for photovoltaics must be provided by the Federal Government because the solar industry today does not reap enough profits from its present-day sales of photovoltaic equipment.

  13. Meta-analyses of the proportion of Japanese encephalitis virus infection in vectors and vertebrate hosts.

    Science.gov (United States)

    Oliveira, Ana R S; Cohnstaedt, Lee W; Strathe, Erin; Hernández, Luciana Etcheverry; McVey, D Scott; Piaggio, José; Cernicchiaro, Natalia

    2017-09-07

    Japanese encephalitis (JE) is a zoonosis in Southeast Asia vectored by mosquitoes infected with the Japanese encephalitis virus (JEV). Japanese encephalitis is considered an emerging exotic infectious disease with potential for introduction in currently JEV-free countries. Pigs and ardeid birds are reservoir hosts and play a major role on the transmission dynamics of the disease. The objective of the study was to quantitatively summarize the proportion of JEV infection in vectors and vertebrate hosts from data pertaining to observational studies obtained in a systematic review of the literature on vector and host competence for JEV, using meta-analyses. Data gathered in this study pertained to three outcomes: proportion of JEV infection in vectors, proportion of JEV infection in vertebrate hosts, and minimum infection rate (MIR) in vectors. Random-effects subgroup meta-analysis models were fitted by species (mosquito or vertebrate host species) to estimate pooled summary measures, as well as to compute the variance between studies. Meta-regression models were fitted to assess the association between different predictors and the outcomes of interest and to identify sources of heterogeneity among studies. Predictors included in all models were mosquito/vertebrate host species, diagnostic methods, mosquito capture methods, season, country/region, age category, and number of mosquitos per pool. Mosquito species, diagnostic method, country, and capture method represented important sources of heterogeneity associated with the proportion of JEV infection; host species and region were considered sources of heterogeneity associated with the proportion of JEV infection in hosts; and diagnostic and mosquito capture methods were deemed important contributors of heterogeneity for the MIR outcome. Our findings provide reference pooled summary estimates of vector competence for JEV for some mosquito species, as well as of sources of variability for these outcomes. Moreover, this

  14. Marital status integration and suicide: A meta-analysis and meta-regression.

    Science.gov (United States)

    Kyung-Sook, Woo; SangSoo, Shin; Sangjin, Shin; Young-Jeon, Shin

    2018-01-01

    Marital status is an index of the phenomenon of social integration within social structures and has long been identified as an important predictor suicide. However, previous meta-analyses have focused only on a particular marital status, or not sufficiently explored moderators. A meta-analysis of observational studies was conducted to explore the relationships between marital status and suicide and to understand the important moderating factors in this association. Electronic databases were searched to identify studies conducted between January 1, 2000 and June 30, 2016. We performed a meta-analysis, subgroup analysis, and meta-regression of 170 suicide risk estimates from 36 publications. Using random effects model with adjustment for covariates, the study found that the suicide risk for non-married versus married was OR = 1.92 (95% CI: 1.75-2.12). The suicide risk was higher for non-married individuals aged analysis by gender, non-married men exhibited a greater risk of suicide than their married counterparts in all sub-analyses, but women aged 65 years or older showed no significant association between marital status and suicide. The suicide risk in divorced individuals was higher than for non-married individuals in both men and women. The meta-regression showed that gender, age, and sample size affected between-study variation. The results of the study indicated that non-married individuals have an aggregate higher suicide risk than married ones. In addition, gender and age were confirmed as important moderating factors in the relationship between marital status and suicide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Meta-analyses of cognitive and motor function in youth aged 16 years and younger who subsequently develop schizophrenia.

    Science.gov (United States)

    Dickson, H; Laurens, K R; Cullen, A E; Hodgins, S

    2012-04-01

    Previous reviews have reported cognitive and motor deficits in childhood and adolescence among individuals who later develop schizophrenia. However, these reviews focused exclusively on studies of individuals with affected relatives or on population/birth cohorts, incorporated studies with estimated measures of pre-morbid intelligence, or included investigations that examined symptomatic at-risk participants or participants 18 years or older. Thus, it remains unclear whether cognitive and motor deficits constitute robust antecedents of schizophrenia. Meta-analyses were conducted on published studies that examined cognitive or motor function in youth aged 16 years or younger who later developed schizophrenia or a schizophrenia spectrum disorder (SSD) and those who did not. Twenty-three studies fulfilled the following inclusion criteria: (1) written in English; (2) prospective investigations of birth or genetic high-risk cohorts, or follow-back investigations of population samples; (3) objective measures of cognitive or motor performance at age 16 or younger; (4) results provided for individuals who did and who did not develop schizophrenia/SSD later in life; and (5) sufficient data to calculate effect sizes. Four domains of function were examined: IQ; Motor Function; General Academic Achievement; and Mathematics Achievement. Meta-analyses showed that, by age 16, individuals who subsequently developed schizophrenia/SSD displayed significant deficits in IQ (d=0.51) and motor function (d=0.56), but not in general academic achievement (d=0.25) or mathematics achievement (d=0.21). Subsidiary analysis indicated that the IQ deficit was present by age 13. These results demonstrate that deficits in IQ and motor performance precede the prodrome and the onset of illness.

  16. The Effectiveness of Smartphone Apps for Lifestyle Improvement in Noncommunicable Diseases: Systematic Review and Meta-Analyses.

    Science.gov (United States)

    Lunde, Pernille; Nilsson, Birgitta Blakstad; Bergland, Astrid; Kværner, Kari Jorunn; Bye, Asta

    2018-05-04

    Noncommunicable diseases (NCDs) account for 70% of all deaths in a year globally. The four main NCDs are cardiovascular diseases, cancers, chronic pulmonary diseases, and diabetes mellitus. Fifty percent of persons with NCD do not adhere to prescribed treatment; in fact, adherence to lifestyle interventions is especially considered as a major challenge. Smartphone apps permit structured monitoring of health parameters, as well as the opportunity to receive feedback. The aim of this study was to review and assess the effectiveness of app-based interventions, lasting at least 3 months, to promote lifestyle changes in patients with NCDs. In February 2017, a literature search in five databases (EMBASE, MEDLINE, CINAHL, Academic Research Premier, and Cochrane Reviews and Trials) was conducted. Inclusion criteria was quantitative study designs including randomized and nonrandomized controlled trials that included patients aged 18 years and older diagnosed with any of the four main NCDs. Lifestyle outcomes were physical activity, physical fitness, modification of dietary habits, and quality of life. All included studies were assessed for risk of bias using the Cochrane Collaboration`s risk of bias tool. Meta-analyses were conducted for one of the outcomes (glycated hemoglobin, HbA 1c ) by using the estimate of effect of mean post treatment with SD or CI. Heterogeneity was tested using the I 2 test. All studies included in the meta-analyses were graded. Of the 1588 records examined, 9 met the predefined criteria. Seven studies included diabetes patients only, one study included heart patients only, and another study included both diabetes and heart patients. Statistical significant effect was shown in HbA 1c in 5 of 8 studies, as well in body weight in one of 5 studies and in waist circumference in one of 3 studies evaluating these outcomes. Seven of the included studies were included in the meta-analyses and demonstrated significantly overall effect on HbA 1c on a short

  17. Empirical Comparison of Publication Bias Tests in Meta-Analysis.

    Science.gov (United States)

    Lin, Lifeng; Chu, Haitao; Murad, Mohammad Hassan; Hong, Chuan; Qu, Zhiyong; Cole, Stephen R; Chen, Yong

    2018-04-16

    Decision makers rely on meta-analytic estimates to trade off benefits and harms. Publication bias impairs the validity and generalizability of such estimates. The performance of various statistical tests for publication bias has been largely compared using simulation studies and has not been systematically evaluated in empirical data. This study compares seven commonly used publication bias tests (i.e., Begg's rank test, trim-and-fill, Egger's, Tang's, Macaskill's, Deeks', and Peters' regression tests) based on 28,655 meta-analyses available in the Cochrane Library. Egger's regression test detected publication bias more frequently than other tests (15.7% in meta-analyses of binary outcomes and 13.5% in meta-analyses of non-binary outcomes). The proportion of statistically significant publication bias tests was greater for larger meta-analyses, especially for Begg's rank test and the trim-and-fill method. The agreement among Tang's, Macaskill's, Deeks', and Peters' regression tests for binary outcomes was moderately strong (most κ's were around 0.6). Tang's and Deeks' tests had fairly similar performance (κ > 0.9). The agreement among Begg's rank test, the trim-and-fill method, and Egger's regression test was weak or moderate (κ < 0.5). Given the relatively low agreement between many publication bias tests, meta-analysts should not rely on a single test and may apply multiple tests with various assumptions. Non-statistical approaches to evaluating publication bias (e.g., searching clinical trials registries, records of drug approving agencies, and scientific conference proceedings) remain essential.

  18. Development and validation of MIX: comprehensive free software for meta-analysis of causal research data

    Directory of Open Access Journals (Sweden)

    Ikeda Noriaki

    2006-10-01

    Full Text Available Abstract Background Meta-analysis has become a well-known method for synthesis of quantitative data from previously conducted research in applied health sciences. So far, meta-analysis has been particularly useful in evaluating and comparing therapies and in assessing causes of disease. Consequently, the number of software packages that can perform meta-analysis has increased over the years. Unfortunately, it can take a substantial amount of time to get acquainted with some of these programs and most contain little or no interactive educational material. We set out to create and validate an easy-to-use and comprehensive meta-analysis package that would be simple enough programming-wise to remain available as a free download. We specifically aimed at students and researchers who are new to meta-analysis, with important parts of the development oriented towards creating internal interactive tutoring tools and designing features that would facilitate usage of the software as a companion to existing books on meta-analysis. Results We took an unconventional approach and created a program that uses Excel as a calculation and programming platform. The main programming language was Visual Basic, as implemented in Visual Basic 6 and Visual Basic for Applications in Excel 2000 and higher. The development took approximately two years and resulted in the 'MIX' program, which can be downloaded from the program's website free of charge. Next, we set out to validate the MIX output with two major software packages as reference standards, namely STATA (metan, metabias, and metatrim and Comprehensive Meta-Analysis Version 2. Eight meta-analyses that had been published in major journals were used as data sources. All numerical and graphical results from analyses with MIX were identical to their counterparts in STATA and CMA. The MIX program distinguishes itself from most other programs by the extensive graphical output, the click-and-go (Excel interface, and the

  19. Genome-Wide Association Meta-Analyses to Identify Common Genetic Variants Associated with Hallux Valgus in Caucasian and African Americans

    Science.gov (United States)

    Hsu, Yi-Hsiang; Liu, Youfang; Hannan, Marian T.; Maixner, William; Smith, Shad B.; Diatchenko, Luda; Golightly, Yvonne M.; Menz, Hylton B.; Kraus, Virginia B.; Doherty, Michael; Wilson, A.G.; Jordan, Joanne M.

    2016-01-01

    Objective Hallux valgus (HV) affects ~36% of Caucasian adults. Although considered highly heritable, the underlying genetic determinants are unclear. We conducted the first genome-wide association study (GWAS) aimed to identify genetic variants associated with HV. Methods HV was assessed in 3 Caucasian cohorts (n=2,263, n=915, and n=1,231 participants, respectively). In each cohort, a GWAS was conducted using 2.5M imputed single nucleotide polymorphisms (SNPs). Mixed-effect regression with the additive genetic model adjusted for age, sex, weight and within-family correlations was used for both sex-specific and combined analyses. To combine GWAS results across cohorts, fixed-effect inverse-variance meta-analyses were used. Following meta-analyses, top-associated findings were also examined in an African American cohort (n=327). Results The proportion of HV variance explained by genome-wide genotyped SNPs was 50% in men and 48% in women. A higher proportion of genetic determinants of HV was sex-specific. The most significantly associated SNP in men was rs9675316 located on chr17q23-a24 near the AXIN2 gene (p=5.46×10−7); the most significantly associated SNP in women was rs7996797 located on chr13q14.1-q14.2 near the ESD gene (p=7.21×10−7). Genome-wide significant SNP-by-sex interaction was found for SNP rs1563374 located on chr11p15.1 near the MRGPRX3 gene (interaction p-value =4.1×10−9). The association signals diminished when combining men and women. Conclusion Findings suggest that the potential pathophysiological mechanisms of HV are complex and strongly underlined by sex-specific interactions. The identified genetic variants imply contribution of biological pathways observed in osteoarthritis as well as new pathways, influencing skeletal development and inflammation. PMID:26337638

  20. Comparison of pharmacological and non-pharmacological interventions to prevent delirium in critically ill patients: a protocol for a systematic review incorporating network meta-analyses.

    Science.gov (United States)

    Burry, L D; Hutton, B; Guenette, M; Williamson, D; Mehta, S; Egerod, I; Kanji, S; Adhikari, N K; Moher, D; Martin, C M; Rose, L

    2016-09-08

    Delirium is characterized by acute changes in mental status including inattention, disorganized thinking, and altered level of consciousness, and is highly prevalent in critically ill adults. Delirium has adverse consequences for both patients and the healthcare system; however, at this time, no effective treatment exists. The identification of effective prevention strategies is therefore a clinical and research imperative. An important limitation of previous reviews of delirium prevention is that interventions were considered in isolation and only direct evidence was used. Our systematic review will synthesize all existing data using network meta-analysis, a powerful statistical approach that enables synthesis of both direct and indirect evidence. We will search Ovid MEDLINE, CINAHL, Embase, PsycINFO, and Web of Science from 1980 to March 2016. We will search the PROSPERO registry for protocols and the Cochrane Library for published systematic reviews. We will examine reference lists of pertinent reviews and search grey literature and the International Clinical Trials Registry Platform for unpublished studies and ongoing trials. We will include randomized and quasi-randomized trials of critically ill adults evaluating any pharmacological, non-pharmacological, or multi-component intervention for delirium prevention, administered in or prior to (i.e., peri-operatively) transfer to the ICU. Two authors will independently screen search results and extract data from eligible studies. Risk of bias assessments will be completed on all included studies. To inform our network meta-analysis, we will first conduct conventional pair-wise meta-analyses for primary and secondary outcomes using random-effects models. We will generate our network meta-analysis using a Bayesian framework, assuming a common heterogeneity parameter across all comparisons, and accounting for correlations in multi-arm studies. We will perform analyses using WinBUGS software. This systematic review

  1. Inflammatory bowel disease meta-evidence and its challenges

    DEFF Research Database (Denmark)

    Delaney, J; Laws, P; Wille-Jørgensen, P

    2015-01-01

    AIM: The aim of this study was to compare the methodological quality and input paper characteristics of systematic reviews and meta-analyses reported in the medical and surgical literature by performing a systematic 'overview of reviews'. Ulcerative colitis (UC) and Crohn's disease (CD) were used...... offer a positive conclusion. The papers used to generate meta-evidence in M papers have a greater degree of corporate and government sponsorship, and are more likely to come from journals with higher impact factors.......AIM: The aim of this study was to compare the methodological quality and input paper characteristics of systematic reviews and meta-analyses reported in the medical and surgical literature by performing a systematic 'overview of reviews'. Ulcerative colitis (UC) and Crohn's disease (CD) were used...... as the framework for this comparison as they are relatively common serious conditions, with both medical and surgical options for therapy. METHOD: Medline, Embase, CINHAL and the Cochrane Database were searched to November 2013. Eligible papers were systematic reviews or meta-analyses that considered a question...

  2. A meta-analysis of neuropsychological outcome after mild traumatic brain injury: re-analyses and reconsiderations of Binder et al. (1997), Frencham et al. (2005), and Pertab et al. (2009).

    Science.gov (United States)

    Rohling, Martin L; Binder, Laurence M; Demakis, George J; Larrabee, Glenn J; Ploetz, Danielle M; Langhinrichsen-Rohling, Jennifer

    2011-05-01

    The meta-analytic findings of Binder et al. (1997) and Frencham et al. (2005) showed that the neuropsychological effect of mild traumatic brain injury (mTBI) was negligible in adults by 3 months post injury. Pertab et al. (2009) reported that verbal paired associates, coding tasks, and digit span yielded significant differences between mTBI and control groups. We re-analyzed data from the 25 studies used in the prior meta-analyses, correcting statistical and methodological limitations of previous efforts, and analyzed the chronicity data by discrete epochs. Three months post injury the effect size of -0.07 was not statistically different from zero and similar to that which has been found in several other meta-analyses (Belanger et al., 2005; Schretlen & Shapiro, 2003). The effect size 7 days post injury was -0.39. The effect of mTBI immediately post injury was largest on Verbal and Visual Memory domains. However, 3 months post injury all domains improved to show non-significant effect sizes. These findings indicate that mTBI has an initial small effect on neuropsychological functioning that dissipates quickly. The evidence of recovery in the present meta-analysis is consistent with previous conclusions of both Binder et al. and Frencham et al. Our findings may not apply to people with a history of multiple concussions or complicated mTBIs.

  3. Drivers of wetland conversion: a global meta-analysis.

    Science.gov (United States)

    van Asselen, Sanneke; Verburg, Peter H; Vermaat, Jan E; Janse, Jan H

    2013-01-01

    Meta-analysis of case studies has become an important tool for synthesizing case study findings in land change. Meta-analyses of deforestation, urbanization, desertification and change in shifting cultivation systems have been published. This present study adds to this literature, with an analysis of the proximate causes and underlying forces of wetland conversion at a global scale using two complementary approaches of systematic review. Firstly, a meta-analysis of 105 case-study papers describing wetland conversion was performed, showing that different combinations of multiple-factor proximate causes, and underlying forces, drive wetland conversion. Agricultural development has been the main proximate cause of wetland conversion, and economic growth and population density are the most frequently identified underlying forces. Secondly, to add a more quantitative component to the study, a logistic meta-regression analysis was performed to estimate the likelihood of wetland conversion worldwide, using globally-consistent biophysical and socioeconomic location factor maps. Significant factors explaining wetland conversion, in order of importance, are market influence, total wetland area (lower conversion probability), mean annual temperature and cropland or built-up area. The regression analyses results support the outcomes of the meta-analysis of the processes of conversion mentioned in the individual case studies. In other meta-analyses of land change, similar factors (e.g., agricultural development, population growth, market/economic factors) are also identified as important causes of various types of land change (e.g., deforestation, desertification). Meta-analysis helps to identify commonalities across the various local case studies and identify which variables may lead to individual cases to behave differently. The meta-regression provides maps indicating the likelihood of wetland conversion worldwide based on the location factors that have determined historic

  4. Design basis event consequence analyses for the Yucca Mountain project

    International Nuclear Information System (INIS)

    Orvis, D.D.; Haas, M.N.; Martin, J.H.

    1997-01-01

    Design basis event (DBE) definition and analysis is an ongoing and integrated activity among the design and analysis groups of the Yucca Mountain Project (YMP). DBE's are those that potentially lead to breach of the waste package and waste form (e.g., spent fuel rods) with consequent release of radionuclides to the environment. A Preliminary Hazards Analysis (PHA) provided a systematic screening of external and internal events that were candidate DBE's that will be subjected to analyses for radiological consequences. As preparation, pilot consequence analyses for the repository subsurface and surface facilities have been performed to define the methodology, data requirements, and applicable regulatory limits

  5. MetaComp: comprehensive analysis software for comparative meta-omics including comparative metagenomics.

    Science.gov (United States)

    Zhai, Peng; Yang, Longshu; Guo, Xiao; Wang, Zhe; Guo, Jiangtao; Wang, Xiaoqi; Zhu, Huaiqiu

    2017-10-02

    During the past decade, the development of high throughput nucleic sequencing and mass spectrometry analysis techniques have enabled the characterization of microbial communities through metagenomics, metatranscriptomics, metaproteomics and metabolomics data. To reveal the diversity of microbial communities and interactions between living conditions and microbes, it is necessary to introduce comparative analysis based upon integration of all four types of data mentioned above. Comparative meta-omics, especially comparative metageomics, has been established as a routine process to highlight the significant differences in taxon composition and functional gene abundance among microbiota samples. Meanwhile, biologists are increasingly concerning about the correlations between meta-omics features and environmental factors, which may further decipher the adaptation strategy of a microbial community. We developed a graphical comprehensive analysis software named MetaComp comprising a series of statistical analysis approaches with visualized results for metagenomics and other meta-omics data comparison. This software is capable to read files generated by a variety of upstream programs. After data loading, analyses such as multivariate statistics, hypothesis testing of two-sample, multi-sample as well as two-group sample and a novel function-regression analysis of environmental factors are offered. Here, regression analysis regards meta-omic features as independent variable and environmental factors as dependent variables. Moreover, MetaComp is capable to automatically choose an appropriate two-group sample test based upon the traits of input abundance profiles. We further evaluate the performance of its choice, and exhibit applications for metagenomics, metaproteomics and metabolomics samples. MetaComp, an integrative software capable for applying to all meta-omics data, originally distills the influence of living environment on microbial community by regression analysis

  6. Incorporating alternative design clinical trials in network meta-analyses

    Directory of Open Access Journals (Sweden)

    Thorlund K

    2014-12-01

    Full Text Available Kristian Thorlund,1–3 Eric Druyts,1,4 Kabirraaj Toor,1,5 Jeroen P Jansen,1,6 Edward J Mills1,3 1Redwood Outcomes, Vancouver, BC, 2Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton, ON, Canada; 3Stanford Prevention Research Center, Stanford University, Stanford, CA, USA; 4Department of Medicine, Faculty of Medicine, 5School of Population and Public Health, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; 6Department of Public Health and Community Medicine, Tufts University, Boston, MA, USA Introduction: Network meta-analysis (NMA is an extension of conventional pairwise meta-analysis that allows for simultaneous comparison of multiple interventions. Well-established drug class efficacies have become commonplace in many disease areas. Thus, for reasons of ethics and equipoise, it is not practical to randomize patients to placebo or older drug classes. Unique randomized clinical trial designs are an attempt to navigate these obstacles. These alternative designs, however, pose challenges when attempting to incorporate data into NMAs. Using ulcerative colitis as an example, we illustrate an example of a method where data provided by these trials are used to populate treatment networks. Methods: We present the methods used to convert data from the PURSUIT trial into a typical parallel design for inclusion in our NMA. Data were required for three arms: golimumab 100 mg; golimumab 50 mg; and placebo. Golimumab 100 mg induction data were available; however, data regarding those individuals who were nonresponders at induction and those who were responders at maintenance were not reported, and as such, had to be imputed using data from the rerandomization phase. Golimumab 50 mg data regarding responses at week 6 were not available. Existing relationships between the available components were used to impute the expected proportions in this missing subpopulation. Data for placebo maintenance

  7. Chlorination disinfection by-products in drinking water and congenital anomalies: review and meta-analyses Subprodutos da desinfecção com cloro em água potável e anomalias congênitas: revisão e meta-análise

    Directory of Open Access Journals (Sweden)

    Mark J. Nieuwenhuijsen

    2010-10-01

    Full Text Available This study aims to review epidemiologic evidence of the association between exposure to chlorination disinfection by-products (DBPs and congenital anomalies. All epidemiologic studies that evaluated a relationship between an index of DBP exposure and risk of congenital anomalies were analyzed. For all congenital anomalies combined, the meta-analysis gave a statistically significant excess risk for high versus low exposure to water chlorination or TTHM (17%; 95% CI, 3-34 based on a small number of studies. The meta-analysis also suggested a statistically significant excess risk for ventricular septal defects (58%; 95% CI, 21-107, but based on only three studies, and there was little evidence of an exposure-response relationship. It was observed no statistically significant relationships in the other meta-analyses and little evidence for publication bias, except for urinary tract defects and cleft lip and palate. Although some individual studies have suggested an association between chlorination disinfection by-products and congenital anomalies, meta-analyses of all currently available studies demonstrate little evidence of such association.O objetivo deste estudo é revisar evidências epidemiológicas da associação entre a exposição a subprodutos da desinfecção com cloro (DBPs e anomalias congênitas. Todos os estudos epidemiológicos que avaliaram a relação entre o índice de exposição a DBPs e o risco de anomalias congênitas foram analisados. Para todas as anomalias congênitas combinadas, a meta-análise resultou em um risco de excesso estatisticamente significante para alta versus baixa exposição à cloração da água ou ao TTHM (17%; 95% CI, 3-34 baseado em um pequeno número de estudos. A meta-análise também sugere um excesso de risco estatisticamente significante para defeitos septais ventriculares (58%; 95% CI, 21-107, porém com base em apenas três estudos, nos quais se encontrou pouca evidência na relação exposi

  8. Improved Dietary Guidelines for Vitamin D: Application of Individual Participant Data (IPD)-Level Meta-Regression Analyses

    Science.gov (United States)

    Cashman, Kevin D.; Ritz, Christian; Kiely, Mairead

    2017-01-01

    Dietary Reference Values (DRVs) for vitamin D have a key role in the prevention of vitamin D deficiency. However, despite adopting similar risk assessment protocols, estimates from authoritative agencies over the last 6 years have been diverse. This may have arisen from diverse approaches to data analysis. Modelling strategies for pooling of individual subject data from cognate vitamin D randomized controlled trials (RCTs) are likely to provide the most appropriate DRV estimates. Thus, the objective of the present work was to undertake the first-ever individual participant data (IPD)-level meta-regression, which is increasingly recognized as best practice, from seven winter-based RCTs (with 882 participants ranging in age from 4 to 90 years) of the vitamin D intake–serum 25-hydroxyvitamin D (25(OH)D) dose-response. Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of 25(OH)D concentrations >25, 30, and 50 nmol/L across the population are 10, 13, and 26 µg/day, respectively. In contrast, standard meta-regression analyses with aggregate data (as used by several agencies in recent years) from the same RCTs estimated that a vitamin D intake requirement of 14 µg/day would maintain 97.5% of 25(OH)D >50 nmol/L. These first IPD-derived estimates offer improved dietary recommendations for vitamin D because the underpinning modeling captures the between-person variability in response of serum 25(OH)D to vitamin D intake. PMID:28481259

  9. Improved Dietary Guidelines for Vitamin D: Application of Individual Participant Data (IPD-Level Meta-Regression Analyses

    Directory of Open Access Journals (Sweden)

    Kevin D. Cashman

    2017-05-01

    Full Text Available Dietary Reference Values (DRVs for vitamin D have a key role in the prevention of vitamin D deficiency. However, despite adopting similar risk assessment protocols, estimates from authoritative agencies over the last 6 years have been diverse. This may have arisen from diverse approaches to data analysis. Modelling strategies for pooling of individual subject data from cognate vitamin D randomized controlled trials (RCTs are likely to provide the most appropriate DRV estimates. Thus, the objective of the present work was to undertake the first-ever individual participant data (IPD-level meta-regression, which is increasingly recognized as best practice, from seven winter-based RCTs (with 882 participants ranging in age from 4 to 90 years of the vitamin D intake–serum 25-hydroxyvitamin D (25(OHD dose-response. Our IPD-derived estimates of vitamin D intakes required to maintain 97.5% of 25(OHD concentrations >25, 30, and 50 nmol/L across the population are 10, 13, and 26 µg/day, respectively. In contrast, standard meta-regression analyses with aggregate data (as used by several agencies in recent years from the same RCTs estimated that a vitamin D intake requirement of 14 µg/day would maintain 97.5% of 25(OHD >50 nmol/L. These first IPD-derived estimates offer improved dietary recommendations for vitamin D because the underpinning modeling captures the between-person variability in response of serum 25(OHD to vitamin D intake.

  10. How to conduct a qualitative meta-analysis: Tailoring methods to enhance methodological integrity.

    Science.gov (United States)

    Levitt, Heidi M

    2018-05-01

    Although qualitative research has long been of interest in the field of psychology, meta-analyses of qualitative literatures (sometimes called meta-syntheses) are still quite rare. Like quantitative meta-analyses, these methods function to aggregate findings and identify patterns across primary studies, but their aims, procedures, and methodological considerations may vary. This paper explains the function of qualitative meta-analyses and their methodological development. Recommendations have broad relevance but are framed with an eye toward their use in psychotherapy research. Rather than arguing for the adoption of any single meta-method, this paper advocates for considering how procedures can best be selected and adapted to enhance a meta-study's methodological integrity. Through the paper, recommendations are provided to help researchers identify procedures that can best serve their studies' specific goals. Meta-analysts are encouraged to consider the methodological integrity of their studies in relation to central research processes, including identifying a set of primary research studies, transforming primary findings into initial units of data for a meta-analysis, developing categories or themes, and communicating findings. The paper provides guidance for researchers who desire to tailor meta-analytic methods to meet their particular goals while enhancing the rigor of their research.

  11. Baseline micronuclei frequency in children: estimates from meta- and pooled analyses

    DEFF Research Database (Denmark)

    Neri, Monica; Ceppi, Marcello; Knudsen, Lisbeth E

    2005-01-01

    the statistical power of studies and to assess the quality of data. In this article, we provide estimates of the baseline frequency of MN in children, conducting a meta-analysis of MN frequency reported by field studies in children and a pooled analysis of individual data [available from published studies...

  12. Drivers of Wetland Conversion: a Global Meta-Analysis

    NARCIS (Netherlands)

    van Asselen, S.; Verburg, P.H.; Vermaat, J.E.; Janse, J.

    2013-01-01

    Meta-analysis of case studies has become an important tool for synthesizing case study findings in land change. Meta-analyses of deforestation, urbanization, desertification and change in shifting cultivation systems have been published. This present study adds to this literature, with an analysis

  13. Online Open Neuroimaging Mass Meta-Analysis with a Wiki

    DEFF Research Database (Denmark)

    Nielsen, Finn Arup; Kempton, Matthew J.; Williams, Steven C. R.

    2015-01-01

    We describe a system for meta-analysis where a wiki stores numerical data in a simple comma-separated values format and a web service performs the numerical statistical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system...... allows for mass meta-analysis, e.g., meta-analysis across multiple brain regions and multiple mental disorders providing an overview of important relationships and their uncertainties in a collaborative environment....

  14. Psychometric Properties of “Community Assessment of Psychic Experiences”: Review and Meta-analyses

    Science.gov (United States)

    Mark, Winifred; Toulopoulou, Timothea

    2016-01-01

    The Community Assessment of Psychic Experiences (CAPE) has been used extensively as a measurement for psychosis proneness in clinical and research settings. However, no prior review and meta-analysis have comprehensively examined psychometric properties (reliability and validity) of CAPE scores across different studies. To study CAPE’s internal reliability—ie, how well scale items correlate with one another—111 studies were reviewed. Of these, 18 reported unique internal reliability coefficients using data at hand, which were aggregated in a meta-analysis. Furthermore, to confirm the number and nature of factors tapped by CAPE, 17 factor analytic studies were reviewed and subjected to meta-analysis in cases of discrepancy. Results suggested that CAPE scores were psychometrically reliable—ie, scores obtained could be attributed to true score variance. Our review of factor analytic studies supported a 3-factor model for CAPE consisting of “Positive”, “Negative”, and “Depressive” subscales; and a tripartite structure for the Negative dimension consisting of “Social withdrawal”, “Affective flattening”, and “Avolition” subdimensions. Meta-analysis of factor analytic studies of the Positive dimension revealed a tridimensional structure consisting of “Bizarre experiences”, “Delusional ideations”, and “Perceptual anomalies”. Information on reliability and validity of CAPE scores is important for ensuring accurate measurement of the psychosis proneness phenotype, which in turn facilitates early detection and intervention for psychotic disorders. Apart from enhancing the understanding of psychometric properties of CAPE scores, our review revealed questionable reporting practices possibly reflecting insufficient understanding regarding the significance of psychometric properties. We recommend increased focus on psychometrics in psychology programmes and clinical journals. PMID:26150674

  15. Dietary Assessment in the MetaCardis Study

    DEFF Research Database (Denmark)

    Verger, Eric O; Armstrong, Patrice; Nielsen, Trine

    2017-01-01

    Cardis FFQ and 3 consecutive self-administered web-based 24-hour dietary recalls (DRs). STATISTICAL ANALYSES PERFORMED: Several measures of validity of the French MetaCardis FFQ were evaluated: estimations of food groups, energy, and nutrient intakes from the DRs and the FFQ, Spearman and Pearson...... correlations, cross-classification, and Bland-Altman analyses. RESULTS: The French MetaCardis FFQ tended to report higher food, energy, and nutrient intakes compared with the DRs. Mean correlation coefficient was 0.429 for food, 0.460 for energy, 0.544 for macronutrients, 0.640 for alcohol, and 0...

  16. Systematic Comparison of Brain Imaging Meta-Analyses of ToM with vPT.

    Science.gov (United States)

    Arora, Aditi; Schurz, Matthias; Perner, Josef

    2017-01-01

    In visual perspective taking (vPT) one has to concern oneself with what other people see and how they see it. Since seeing is a mental state, developmental studies have discussed vPT within the domain of "theory of mind (ToM)" but imaging studies have not treated it as such. Based on earlier results from several meta-analyses, we tested for the overlap of visual perspective taking studies with 6 different kinds of ToM studies: false belief, trait judgments, strategic games, social animations, mind in the eyes, and rational actions. Joint activation was observed between the vPT task and some kinds of ToM tasks in regions involving the left temporoparietal junction (TPJ), anterior precuneus, left middle occipital gyrus/extrastriate body area (EBA), and the left inferior frontal and precentral gyrus. Importantly, no overlap activation was found for the vPT tasks with the joint core of all six kinds of ToM tasks. This raises the important question of what the common denominator of all tasks that fall under the label of "theory of mind" is supposed to be if visual perspective taking is not one of them.

  17. The Relationship between physical activity and risk of atrial fibrillation-A systematic review and meta-Analysis

    DEFF Research Database (Denmark)

    Nielsen, Jens Erik Rokkedal; Wachtell, K; Abdulla, J

    2013-01-01

    The aim of this systematic literature review and meta-Analyses was to explore the relationship between physical activity and risk of new-onset atrial fibrillation (AF) or flutter (AFlu).Results: The search revealed 10 published studies that were eligible for three different meta-Analyses. A meta...

  18. Meta-analysis of randomized clinical trials in the era of individual patient data sharing.

    Science.gov (United States)

    Kawahara, Takuya; Fukuda, Musashi; Oba, Koji; Sakamoto, Junichi; Buyse, Marc

    2018-06-01

    Individual patient data (IPD) meta-analysis is considered to be a gold standard when the results of several randomized trials are combined. Recent initiatives on sharing IPD from clinical trials offer unprecedented opportunities for using such data in IPD meta-analyses. First, we discuss the evidence generated and the benefits obtained by a long-established prospective IPD meta-analysis in early breast cancer. Next, we discuss a data-sharing system that has been adopted by several pharmaceutical sponsors. We review a number of retrospective IPD meta-analyses that have already been proposed using this data-sharing system. Finally, we discuss the role of data sharing in IPD meta-analysis in the future. Treatment effects can be more reliably estimated in both types of IPD meta-analyses than with summary statistics extracted from published papers. Specifically, with rich covariate information available on each patient, prognostic and predictive factors can be identified or confirmed. Also, when several endpoints are available, surrogate endpoints can be assessed statistically. Although there are difficulties in conducting, analyzing, and interpreting retrospective IPD meta-analysis utilizing the currently available data-sharing systems, data sharing will play an important role in IPD meta-analysis in the future.

  19. ArrayWiki: an enabling technology for sharing public microarray data repositories and meta-analyses

    Science.gov (United States)

    Stokes, Todd H; Torrance, JT; Li, Henry; Wang, May D

    2008-01-01

    Background A survey of microarray databases reveals that most of the repository contents and data models are heterogeneous (i.e., data obtained from different chip manufacturers), and that the repositories provide only basic biological keywords linking to PubMed. As a result, it is difficult to find datasets using research context or analysis parameters information beyond a few keywords. For example, to reduce the "curse-of-dimension" problem in microarray analysis, the number of samples is often increased by merging array data from different datasets. Knowing chip data parameters such as pre-processing steps (e.g., normalization, artefact removal, etc), and knowing any previous biological validation of the dataset is essential due to the heterogeneity of the data. However, most of the microarray repositories do not have meta-data information in the first place, and do not have a a mechanism to add or insert this information. Thus, there is a critical need to create "intelligent" microarray repositories that (1) enable update of meta-data with the raw array data, and (2) provide standardized archiving protocols to minimize bias from the raw data sources. Results To address the problems discussed, we have developed a community maintained system called ArrayWiki that unites disparate meta-data of microarray meta-experiments from multiple primary sources with four key features. First, ArrayWiki provides a user-friendly knowledge management interface in addition to a programmable interface using standards developed by Wikipedia. Second, ArrayWiki includes automated quality control processes (caCORRECT) and novel visualization methods (BioPNG, Gel Plots), which provide extra information about data quality unavailable in other microarray repositories. Third, it provides a user-curation capability through the familiar Wiki interface. Fourth, ArrayWiki provides users with simple text-based searches across all experiment meta-data, and exposes data to search engine crawlers

  20. Serum Lipid Profiles and Cancer Risk in the Context of Obesity: Four Meta-Analyses

    International Nuclear Information System (INIS)

    Melvin, J. C.; Holmberg, L.; Hemelrijck, M. V.

    2013-01-01

    The objective here was to summarize the evidence for, and quantify the link between, serum markers of lipid metabolism and risk of obesity-related cancers. Pub Med and Embase were searched using predefined inclusion criteria to conduct meta-analyses on the association between serum levels of TG, TC, HDL, ApoA-I, and risk of 11 obesity-related cancers. Pooled relative risks (RRs) and 95% confidence intervals were estimated using random-effects analyses. 28 studies were included. Associations between abnormal lipid components and risk of obesity-related cancers when using clinical cut points ( TC ≥ 6.50; TG ≥ 1.71; HDL ≤ 1.03; ApoA-I ≤ 1.05 mmol/L) were apparent in all models. RRs were 1.18 (95% CI: 1.08-1.29) for TC, 1.20 (1.07-1.35) for TG, 1.15 (1.01-1.32) for HDL, and 1.42 (1.17-1.74) for ApoA-I. High levels of TC and TG, as well as low levels of HDL and ApoA-I, were consistently associated with increased risk of obesity-related cancers. The modest RRs suggest serum lipids to be associated with the risk of cancer, but indicate it is likely that other markers of the metabolism and/or lifestyle factors may also be involved. Future intervention studies involving lifestyle modification would provide insight into the potential biological role of lipid metabolism in tumorigenesis.

  1. The role of pragmatism in explaining heterogeneity in meta-analyses of randomised trials: a protocol for a cross-sectional methodological review

    Science.gov (United States)

    Aves, Theresa; Lawson, Daeria; Nieuwlaat, Robby; Beyene, Joseph; Mbuagbaw, Lawrence

    2017-01-01

    Introduction There has been increasing interest in pragmatic trials methodology. As a result, tools such as the Pragmatic-Explanatory Continuum Indicator Summary-2 (PRECIS-2) are being used prospectively to help researchers design randomised controlled trials (RCTs) within the pragmatic-explanatory continuum. There may be value in applying the PRECIS-2 tool retrospectively in a systematic review setting as it could provide important information about how to pool data based on the degree of pragmatism. Objectives To investigate the role of pragmatism as a source of heterogeneity in systematic reviews by (1) identifying systematic reviews with meta-analyses of RCTs that have moderate to high heterogeneity, (2) applying PRECIS-2 to RCTs of systematic reviews, (3) evaluating the inter-rater reliability of PRECIS-2, (4) determining how much of this heterogeneity may be explained by pragmatism. Methods A cross-sectional methodological review will be conducted on systematic reviews of RCTs published in the Cochrane Library from 1 January 2014 to 1 January 2017. Included systematic reviews will have a minimum of 10 RCTs in the meta-analysis of the primary outcome and moderate to substantial heterogeneity (I2≥50%). Of the eligible systematic reviews, a random selection of 10 will be included for quantitative evaluation. In each systematic review, RCTs will be scored using the PRECIS-2 tool, in duplicate. Agreement between raters will be measured using the intraclass correlation coefficient. Subgroup analyses and meta-regression will be used to evaluate how much variability in the primary outcome may be due to pragmatism. Dissemination This review will be among the first to evaluate the PRECIS-2 tool in a systematic review setting. Results from this research will provide inter-rater reliability information about PRECIS-2 and may be used to provide methodological guidance when dealing with pragmatism in systematic reviews and subgroup considerations. On completion, this

  2. Evaluating the Quality of Evidence from a Network Meta-Analysis

    Science.gov (United States)

    Salanti, Georgia; Del Giovane, Cinzia; Chaimani, Anna; Caldwell, Deborah M.; Higgins, Julian P. T.

    2014-01-01

    Systematic reviews that collate data about the relative effects of multiple interventions via network meta-analysis are highly informative for decision-making purposes. A network meta-analysis provides two types of findings for a specific outcome: the relative treatment effect for all pairwise comparisons, and a ranking of the treatments. It is important to consider the confidence with which these two types of results can enable clinicians, policy makers and patients to make informed decisions. We propose an approach to determining confidence in the output of a network meta-analysis. Our proposed approach is based on methodology developed by the Grading of Recommendations Assessment, Development and Evaluation (GRADE) Working Group for pairwise meta-analyses. The suggested framework for evaluating a network meta-analysis acknowledges (i) the key role of indirect comparisons (ii) the contributions of each piece of direct evidence to the network meta-analysis estimates of effect size; (iii) the importance of the transitivity assumption to the validity of network meta-analysis; and (iv) the possibility of disagreement between direct evidence and indirect evidence. We apply our proposed strategy to a systematic review comparing topical antibiotics without steroids for chronically discharging ears with underlying eardrum perforations. The proposed framework can be used to determine confidence in the results from a network meta-analysis. Judgements about evidence from a network meta-analysis can be different from those made about evidence from pairwise meta-analyses. PMID:24992266

  3. Softwareland Chronicles: A Software Development Meta-Process Proposal

    Directory of Open Access Journals (Sweden)

    Bolanos Sandro

    2016-05-01

    Full Text Available This paper presents the software development meta-process (SD-MP as a proposal to set up software projects. Within this proposal we offer conceptual elements that help solve the war of methodologies and processes in favor of an integrating viewpoint, where the main flaws associated with conventional and agile approaches are removed. Our newly developed software platform to support the meta-process is also presented together with three case studies involving projects currently in progress, where the framework proposed in SD-MP has been applied.

  4. Meta-analysis in microbiology

    Directory of Open Access Journals (Sweden)

    N Pabalan

    2014-01-01

    Full Text Available The use of meta-analysis in microbiology may facilitate decision-making that impacts public health policy. Directed at clinicians and researchers in microbiology, this review outlines the steps in performing this statistical technique, addresses its biases and describes its value in this discipline. The survey to estimate extent of the use of meta-analyses in microbiology shows the remarkable growth in the use of this research methodology, from a minimal Asian output to a level comparable with those of Europe and North America in the last 7 years.

  5. Novel citation-based search method for scientific literature: application to meta-analyses

    NARCIS (Netherlands)

    Janssens, A.C.J.W.; Gwinn, M.

    2015-01-01

    Background: Finding eligible studies for meta-analysis and systematic reviews relies on keyword-based searching as the gold standard, despite its inefficiency. Searching based on direct citations is not sufficiently comprehensive. We propose a novel strategy that ranks articles on their degree of

  6. A meta-analysis of changes in brain activity in clinical depression

    Directory of Open Access Journals (Sweden)

    Susan Mary Palmer

    2015-01-01

    Full Text Available Insights into neurobiological mechanisms of depression are increasingly being sought via brain imaging studies. Our aim was to quantitatively summarize overlap and divergence in regions of altered brain activation associated with depression under emotionally-valenced compared to cognitively-demanding task conditions, with reference to intrinsic functional connectivity. We hypothesized differences reflective of task demands. A coordinate-based meta-analysis technique, Activation Likelihood Estimation (ALE, was used to analyze relevant imaging literature. These studies compared brain activity in depressed adults relative to healthy controls during three conditions: (i emotionally-valenced (cognitively easy tasks (n=29; (ii cognitively-demanding tasks (n=15; and (iii resting conditions (n=21.The meta-analyses identified 5, 8 and 7 significant clusters of altered brain activity under emotion, cognition and resting conditions respectively in depressed individuals compared to healthy controls. Regions of overlap and divergence between pairs of the three separate meta-analyses were quantified. There were no significant regions of overlap between emotion and cognition meta-analyses, but several divergent clusters were found. Cognitively-demanding conditions were associated with greater activation of right medial frontal and insula regions while bilateral amygdala was more significantly altered during emotion (cognitively-undemanding conditions; consistent with task demands.Overlap was present in left amygdala and right subcallosal cingulate between emotion and resting meta-analyses, with no significant divergence.Our meta-analyses highlight alteration of common brain regions, during cognitively-undemanding emotional tasks and resting conditions but divergence of regions between emotional and cognitively-demanding tasks. Regions altered reflect current biological and system-level models of depression and highlight the relationship with task condition and

  7. Validity of recalled v. recorded birth weight: a systematic review and meta-analysis

    OpenAIRE

    Shenkin, S.D.; Zhang, M.G.; Der, G.; Mathur, S.; Mina, T.H.; Reynolds, R.M.

    2017-01-01

    Low birth weight is associated with adverse health outcomes. If birth weight records are not available, studies may use recalled birth weight. It is unclear whether this is reliable. We performed a systematic review and meta-analysis of studies comparing recalled with recorded birth weights. We followed the Meta-Analyses of Observational Studies in Epidemiology (MOOSE) statement and Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched MEDLINE, EM...

  8. MetaQTL: a package of new computational methods for the meta-analysis of QTL mapping experiments

    Directory of Open Access Journals (Sweden)

    Charcosset Alain

    2007-02-01

    Full Text Available Abstract Background Integration of multiple results from Quantitative Trait Loci (QTL studies is a key point to understand the genetic determinism of complex traits. Up to now many efforts have been made by public database developers to facilitate the storage, compilation and visualization of multiple QTL mapping experiment results. However, studying the congruency between these results still remains a complex task. Presently, the few computational and statistical frameworks to do so are mainly based on empirical methods (e.g. consensus genetic maps are generally built by iterative projection. Results In this article, we present a new computational and statistical package, called MetaQTL, for carrying out whole-genome meta-analysis of QTL mapping experiments. Contrary to existing methods, MetaQTL offers a complete statistical process to establish a consensus model for both the marker and the QTL positions on the whole genome. First, MetaQTL implements a new statistical approach to merge multiple distinct genetic maps into a single consensus map which is optimal in terms of weighted least squares and can be used to investigate recombination rate heterogeneity between studies. Secondly, assuming that QTL can be projected on the consensus map, MetaQTL offers a new clustering approach based on a Gaussian mixture model to decide how many QTL underly the distribution of the observed QTL. Conclusion We demonstrate using simulations that the usual model choice criteria from mixture model literature perform relatively well in this context. As expected, simulations also show that this new clustering algorithm leads to a reduction in the length of the confidence interval of QTL location provided that across studies there are enough observed QTL for each underlying true QTL location. The usefulness of our approach is illustrated on published QTL detection results of flowering time in maize. Finally, MetaQTL is freely available at http://bioinformatics.org/mqtl.

  9. Association of study quality with completeness of reporting: have completeness of reporting and quality of systematic reviews and meta-analyses in major radiology journals changed since publication of the PRISMA statement?

    Science.gov (United States)

    Tunis, Adam S; McInnes, Matthew D F; Hanna, Ramez; Esmail, Kaisra

    2013-11-01

    To evaluate whether completeness of reporting of systematic reviews and meta-analyses in major radiology journals has changed since publication of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement; a secondary objective is to evaluate whether completeness of reporting (ie, PRISMA) is associated with study quality (ie, Assessing the Methodological Quality of Systematic Reviews [AMSTAR]). Systematic reviews and meta-analyses published in major radiology journals between January 2007 and December 2011 were identified by searching MEDLINE with the modified Montori method. Studies were reviewed independently by two investigators and assessed for adherence to the AMSTAR and PRISMA checklists. The average results were analyzed to assess for change in mean score before and after PRISMA publication and to assess results over time; a Pearson correlation coefficient was calculated to assess for any association between PRISMA and AMSTAR results. Included were 130 studies from 11 journals. Average PRISMA and AMSTAR results were 21.8 of 27 and 7.2 of 11, respectively. The average result was higher after publication of PRISMA, and PRISMA-reported items were 22.6 of 27 after publication of PRISMA versus 20.9 of 27 before publication of PRISMA; AMSTAR results were 7.7 of 11 after publication of PRISMA versus 6.7 of 11 before publication of PRISMA. There was a strong positive correlation (r = 0.86) between the PRISMA and AMSTAR results. There was high variability between journals. Radiology had the highest PRISMA reported items (24.7 of 27), and American Journal of Neuroradiology had the lowest (19.6 of 27). Two major areas for improvement include study protocol registration and assessment of risk of bias across studies (ie, publication bias). In major radiology journal studies, there was modest improvement in completeness of reporting of systematic reviews and meta-analyses, assessed by PRISMA, which was strongly associated with higher study

  10. Determinants of investment behaviour. Methods and applications of meta-analysis

    International Nuclear Information System (INIS)

    Koetse, M.J.

    2006-01-01

    Meta-analysis is gradually gaining ground in economics as a research method to objectively and quantitatively summarise a body of existing empirical evidence. This dissertation studies the performance of well-known meta-analytic models and presents two meta-analysis applications. Despite its many attractive features, meta-analysis faces several methodical difficulties, especially when applied in economic research. We investigate two specific methodical problems that any meta-analysis in economics will have to deal with, viz., systematic effect-size variation due to primary-study misspecifications, and random effect-size heterogeneity. Using Monte-Carlo analysis we investigate the effects of these methodical problems on the results of a meta-analysis, and study the small-sample properties of several well-known and often applied meta-estimators. The focus of the meta-analysis applications is on two topics that are relevant for understanding investment behaviour, viz., the impact of uncertainty on investment spending, and the potential for substitution of capital for energy in production processes. In the first application we aim to shed light on the direction of the relationship between investment and uncertainty, and to uncover which factors are empirically relevant for explaining the wide variety in study outcomes. In the second application our goal is to analyse the direction and magnitude of capital-energy substitution potential, and to analyse the empirical relevance of suggested sources of variation in elasticity estimates

  11. Determinants of investment behaviour. Methods and applications of meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Koetse, M.J.

    2006-03-14

    Meta-analysis is gradually gaining ground in economics as a research method to objectively and quantitatively summarise a body of existing empirical evidence. This dissertation studies the performance of well-known meta-analytic models and presents two meta-analysis applications. Despite its many attractive features, meta-analysis faces several methodical difficulties, especially when applied in economic research. We investigate two specific methodical problems that any meta-analysis in economics will have to deal with, viz., systematic effect-size variation due to primary-study misspecifications, and random effect-size heterogeneity. Using Monte-Carlo analysis we investigate the effects of these methodical problems on the results of a meta-analysis, and study the small-sample properties of several well-known and often applied meta-estimators. The focus of the meta-analysis applications is on two topics that are relevant for understanding investment behaviour, viz., the impact of uncertainty on investment spending, and the potential for substitution of capital for energy in production processes. In the first application we aim to shed light on the direction of the relationship between investment and uncertainty, and to uncover which factors are empirically relevant for explaining the wide variety in study outcomes. In the second application our goal is to analyse the direction and magnitude of capital-energy substitution potential, and to analyse the empirical relevance of suggested sources of variation in elasticity estimates.

  12. Meta-analyses of the Association of Sleep Apnea with Insulin Resistance, and the Effects of CPAP on HOMA-IR, Adiponectin, and Visceral Adipose Fat.

    Science.gov (United States)

    Iftikhar, Imran H; Hoyos, Camilla M; Phillips, Craig L; Magalang, Ulysses J

    2015-04-15

    We sought to conduct an updated meta-analysis of randomized controlled trials (RCTs) on the effect of continuous positive airway pressure (CPAP) on insulin resistance, as measured by homeostasis model assessment of insulin resistance (HOMA-IR), visceral abdominal fat (VAF), and adiponectin. Additionally, we performed a separate meta-analysis and meta-regression of studies on the association of insulin resistance and obstructive sleep apnea (OSA). All included studies were searched from PubMed (from conception to March 15, 2014). Data were pooled across all included RCTs as the mean difference in HOMA-IR and VAF, and as the standardized mean difference in the case of adiponectin analysis. From the included case-control studies, data on the difference of HOMA-IR between cases and controls were pooled across all studies, as the standardized mean difference (SMD). There was a significant difference in HOMA-IR (-0.43 [95% CIs: -0.75 to -0.11], p = 0.008) between CPAP treated and non CPAP treated participants. However, there was no significant difference in VAF or adiponectin; (-47.93 [95% CI: -112.58 to 16.72], p = 0.14) and (-0.06 [95% CI: -0.28 to 0.15], p = 0.56), respectively. Meta-analysis of 16 case-control studies showed a pooled SMD in HOMA-IR of 0.51 (95% CI: 0.28 to 0.75), p ≤ 0.001, between cases and controls. The results of our meta-analyses show that CPAP has a favorable effect on insulin resistance. This effect is not associated with any significant changes in total adiponectin levels or amount of VAF. Our findings also confirm a significant association between OSA and insulin resistance. © 2015 American Academy of Sleep Medicine.

  13. Diet and ADHD, Reviewing the Evidence: A Systematic Review of Meta-Analyses of Double-Blind Placebo-Controlled Trials Evaluating the Efficacy of Diet Interventions on the Behavior of Children with ADHD.

    Directory of Open Access Journals (Sweden)

    Lidy M Pelsser

    Full Text Available Attention-deficit/hyperactivity disorder (ADHD is a debilitating mental health problem hampering the child's development. The underlying causes include both genetic and environmental factors and may differ between individuals. The efficacy of diet treatments in ADHD was recently evaluated in three reviews, reporting divergent and confusing conclusions based on heterogeneous studies and subjects. To address this inconsistency we conducted a systematic review of meta-analyses of double-blind placebo-controlled trials evaluating the effect of diet interventions (elimination and supplementation on ADHD.Our literature search resulted in 14 meta-analyses, six of which confined to double-blind placebo-controlled trials applying homogeneous diet interventions, i.e. artificial food color (AFC elimination, a few-foods diet (FFD and poly-unsaturated fatty acid (PUFA supplementation. Effect sizes (ES and Confidence intervals (CI of study outcomes were depicted in a forest plot. I2 was calculated to assess heterogeneity if necessary and additional random effects subgroup meta-regression was conducted if substantial heterogeneity was present.The AFC ESs were 0.44 (95% CI: 0.16-0.72, I2 = 11% and 0.21 (95% CI: -0.02-0.43, I2 = 68% [parent ratings], 0.08 (95% CI: -0.07-0.24, I2 = 0% [teacher ratings] and 0.11 (95% CI: -0.13-0.34, I2 = 12% [observer ratings]. The FFD ESs were 0.80 (95% CI: 0.41-1.19, I2 = 61% [parent ratings] and 0.51 (95% CI: -0.02-1.04, I2 = 72% [other ratings], while the PUFA ESs were 0.17 (95% CI: -0.03-0.38, I2 = 38% [parent ratings], -0.05 (95% CI: -0.27-0.18, I2 = 0% [teacher ratings] and 0.16 (95% CI: 0.01-0.31, I2 = 0% [parent and teacher ratings]. Three meta-analyses (two FFD and one AFC resulted in high I2 without presenting subgroup results. The FFD meta-analyses provided sufficient data to perform subgroup analyses on intervention type, resulting in a decrease of heterogeneity to 0% (diet design and 37.8% (challenge design

  14. Epidemiology, quality and reporting characteristics of meta-analyses of observational studies published in Chinese journals.

    Science.gov (United States)

    Zhang, Zhe-wen; Cheng, Juan; Liu, Zhuan; Ma, Ji-chun; Li, Jin-long; Wang, Jing; Yang, Ke-hu

    2015-12-07

    The aim of this study was to examine the epidemiological and reporting characteristics as well as the methodological quality of meta-analyses (MAs) of observational studies published in Chinese journals. 5 Chinese databases were searched for MAs of observational studies published from January 1978 to May 2014. Data were extracted into Excel spreadsheets, and Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Assessment of Multiple Systematic Reviews (AMSTAR) checklists were used to assess reporting characteristics and methodological quality, respectively. A total of 607 MAs were included. Only 52.2% of the MAs assessed the quality of the included primary studies, and the retrieval information was not comprehensive in more than half (85.8%) of the MAs. In addition, 50 (8.2%) MAs did not search any Chinese databases, while 126 (20.8%) studies did not search any English databases. Approximately 41.2% of the MAs did not describe the statistical methods in sufficient details, and most (95.5%) MAs did not report on conflicts of interest. However, compared with the before publication of the MOOSE Checklist, the quality of reporting improved significantly for 20 subitems after publication of the MOOSE Checklist, and 7 items of the included MAs demonstrated significant improvement after publication of the AMSTAR Checklist (pstudies have been published in Chinese journals, the reporting quality is questionable. Thus, there is an urgent need to increase the use of reporting guidelines and methodological tools in China; we recommend that Chinese journals adopt the MOOSE and AMSTAR criteria. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  15. Reevaluation of Meta-analysis on prophylactic drug management for recurrence of febrile seizures

    Directory of Open Access Journals (Sweden)

    Huan LIAO

    2015-08-01

    Full Text Available Objective To explore the efficiency and safety of drugs to prevent the recurrence of febrile seizures (FS.  Methods Relevant literatures were searched via PubMed, EMBASE/SCOPUS, EBSCO-CINAHL, Web of Science, Cochrane Database of Systematic Reviews from December 1997 to November 2014 using the following keywords: febrile seizure OR febrile convulsion, recurrence, prevention OR prophylaxis, medicine OR medication. Publication type was limited to Meta-analysis. Extract the relevant information of Meta-analysis, such as characteristics of objects, types of study design, number of clinical trials, number of cases, search strategies, databases, information of methodology (methods of randomization, concealment, blinding, withdrawal and exit, follow-up time, heterogeneity analysis, subgroup analysis and outcome assessment, etc. Quality of Reporting of Meta-analyses (QUOROM and Oxman-Guyatt Overview Quality Assessment Questionnaire (OQAQ were used to assess the quality of included Meta-analyses. Jadad decision was used to assess inclusion and exclusion criteria, search strategies, effectiveness evaluation, data extraction and data analysis, to explore reliable evidence of evidence-based medicine.  Results Eventually, four Meta-analyses were included after screening of all the literatures that can be searched out. Among those Meta-analyses, the Meta-analysis of Offringa and Newton (2012 was relatively more reliable. The results suggesed that no clinically important benefits were found in administering intermittent oral or rectal diazepam, oral phenobarbitone, phenytoin, valproate, pyridoxine, buprofen, diclofenac and acetominophen to children with FE. Only one clinical trial reported that intermittent oral clobazam could reduce the recurrence of FE in comparing with placebo at 6-month follow-up (RR = 0.360, 95% CI: 0.200-0.640; P = 0.000, but it should be verified by more randomized controlled trials (RCTs. Among 4 Meta-analyses included in this study

  16. Estimates of Between-Study Heterogeneity for 705 Meta-Analyses Reported in Psychological Bulletin From 1990–2013

    Directory of Open Access Journals (Sweden)

    Sara van Erp

    2017-08-01

    Full Text Available We present a data set containing 705 between-study heterogeneity estimates τ2 as reported in 61 articles published in 'Psychological Bulletin' from 1990–2013. The data set also includes information about the number and type of effect sizes, the 'Q'- and 'I'2-statistics, and publication bias. The data set is stored in the Open Science Framework repository (https://osf.io/wyhve/ and can be used for several purposes: (1 to compare a specific heterogeneity estimate to the distribution of between-study heterogeneity estimates in psychology; (2 to construct an informed prior distribution for the between-study heterogeneity in psychology; (3 to obtain realistic population values for Monte Carlo simulations investigating the performance of meta-analytic methods.   Funding statement: This research was supported by the ERC project “Bayes or Bust”.

  17. Genome-wide meta-analyses identify multiple loci associated with smoking behavior.

    LENUS (Irish Health Repository)

    2010-05-01

    Consistent but indirect evidence has implicated genetic factors in smoking behavior. We report meta-analyses of several smoking phenotypes within cohorts of the Tobacco and Genetics Consortium (n = 74,053). We also partnered with the European Network of Genetic and Genomic Epidemiology (ENGAGE) and Oxford-GlaxoSmithKline (Ox-GSK) consortia to follow up the 15 most significant regions (n > 140,000). We identified three loci associated with number of cigarettes smoked per day. The strongest association was a synonymous 15q25 SNP in the nicotinic receptor gene CHRNA3 (rs1051730[A], beta = 1.03, standard error (s.e.) = 0.053, P = 2.8 x 10(-73)). Two 10q25 SNPs (rs1329650[G], beta = 0.367, s.e. = 0.059, P = 5.7 x 10(-10); and rs1028936[A], beta = 0.446, s.e. = 0.074, P = 1.3 x 10(-9)) and one 9q13 SNP in EGLN2 (rs3733829[G], beta = 0.333, s.e. = 0.058, P = 1.0 x 10(-8)) also exceeded genome-wide significance for cigarettes per day. For smoking initiation, eight SNPs exceeded genome-wide significance, with the strongest association at a nonsynonymous SNP in BDNF on chromosome 11 (rs6265[C], odds ratio (OR) = 1.06, 95% confidence interval (Cl) 1.04-1.08, P = 1.8 x 10(-8)). One SNP located near DBH on chromosome 9 (rs3025343[G], OR = 1.12, 95% Cl 1.08-1.18, P = 3.6 x 10(-8)) was significantly associated with smoking cessation.

  18. HIFSA: Heavy-Ion Fusion Systems Assessment Project: Volume 2, Technical analyses

    International Nuclear Information System (INIS)

    Dudziak, D.J.

    1987-12-01

    A two-year project was undertaken to assess the commercial potential of heavy-ion fusion (HIF) as an economical electric power production technology. Because the US HIF development program is oriented toward the use of multiple-beam induction linacs, the study was confined to this particular driver technology. The HIF systems assessment (HIFSA) study involved several subsystem design, performance, and cost studies (e.g., the induction linac, final beam transport, beam transport in reactor cavity environments, cavity clearing, target manufacturing, and reactor plant). In addition, overall power plant systems integration, parametric analyses, and tradeoff studies were performed using a systems code developed specifically for the HIFSA project. Systems analysis results show values for cost of electricity (COE) comparable to those from other inertial- and magnetic-confinement fusion plant studies; viz., 50 to 60 mills/kWh (1985 dollars) for 1-GWe plant sizes. Also, significant COE insensitivity to major accelerator, target, and reactor parameters near the minima was demonstrated. Conclusions from the HIFSA study have already led to substantial modifications of the US HIF research and development program. Separate abstracts were prepared for 17 papers in these analyses

  19. Variables As Currency: Linking Meta-Analysis Research and Data Paths in Sciences

    Directory of Open Access Journals (Sweden)

    Hua Qin

    2014-11-01

    Full Text Available Meta-analyses are studies that bring together data or results from multiple independent studies to produce new and over-arching findings. Current data curation systems only partially support meta-analytic research. Some important meta-analytic tasks, such as the selection of relevant studies for review and the integration of research datasets or findings, are not well supported in current data curation systems. To design tools and services that more fully support meta-analyses, we need a better understanding of meta-analytic research. This includes an understanding of both the practices of researchers who perform the analyses and the characteristics of the individual studies that are brought together. In this study, we make an initial contribution to filling this gap by developing a conceptual framework linking meta-analyses with data paths represented in published articles selected for the analysis. The framework focuses on key variables that represent primary/secondary datasets or derived socio-ecological data, contexts of use, and the data transformations that are applied. We introduce the notion of using variables and their relevant information (e.g., metadata and variable relationships as a type of currency to facilitate synthesis of findings across individual studies and leverage larger bodies of relevant source data produced in small science research. Handling variables in this manner provides an equalizing factor between data from otherwise disparate data-producing communities. We conclude with implications for exploring data integration and synthesis issues as well as system development.

  20. Motivational power of future time perspective: Meta-analyses in education, work, and health.

    Science.gov (United States)

    Andre, Lucija; van Vianen, Annelies E M; Peetsma, Thea T D; Oort, Frans J

    2018-01-01

    Future time perspective (FTP) may predict individual attitudes and behaviors. However, FTP research includes different FTP conceptualizations and outcomes which hinder generalizing its findings. To solve the inconsistencies in FTP research and generalize the magnitude of FTP as a driver of motivation and behavior, we conducted the first systematical synthesis of FTP relationships in three crucial life domains. Our meta-analyses of FTP studies in education (k = 28), work (k = 17), and health (k = 32) involved N = 31,558 participants, and used a conceptual model for grouping FTP constructs. To address different outcome types, we applied the Theory of Planned Behavior when coding the studies. FTP relationships with outcomes were small-to-medium, were generalizable across domains, and were strongest when the FTP construct included a mixture of cognition, behavioral intention, and affect and, in education, when the FTP measure was domain specific rather than general. There were cross-cultural differences in FTP-outcome relationships. The strength of the FTP-outcome types relationship varied for attitudes, perceived behavioral control, behavioral intention, and behaviors. The lowest effect sizes were found for FTP predicting actual behaviors in education, work, and health and between FTP and health attitudes. Theoretical implications of the findings and future research directions are discussed.

  1. Motivational power of future time perspective: Meta-analyses in education, work, and health.

    Directory of Open Access Journals (Sweden)

    Lucija Andre

    Full Text Available Future time perspective (FTP may predict individual attitudes and behaviors. However, FTP research includes different FTP conceptualizations and outcomes which hinder generalizing its findings. To solve the inconsistencies in FTP research and generalize the magnitude of FTP as a driver of motivation and behavior, we conducted the first systematical synthesis of FTP relationships in three crucial life domains. Our meta-analyses of FTP studies in education (k = 28, work (k = 17, and health (k = 32 involved N = 31,558 participants, and used a conceptual model for grouping FTP constructs. To address different outcome types, we applied the Theory of Planned Behavior when coding the studies. FTP relationships with outcomes were small-to-medium, were generalizable across domains, and were strongest when the FTP construct included a mixture of cognition, behavioral intention, and affect and, in education, when the FTP measure was domain specific rather than general. There were cross-cultural differences in FTP-outcome relationships. The strength of the FTP-outcome types relationship varied for attitudes, perceived behavioral control, behavioral intention, and behaviors. The lowest effect sizes were found for FTP predicting actual behaviors in education, work, and health and between FTP and health attitudes. Theoretical implications of the findings and future research directions are discussed.

  2. Motivational power of future time perspective: Meta-analyses in education, work, and health

    Science.gov (United States)

    2018-01-01

    Future time perspective (FTP) may predict individual attitudes and behaviors. However, FTP research includes different FTP conceptualizations and outcomes which hinder generalizing its findings. To solve the inconsistencies in FTP research and generalize the magnitude of FTP as a driver of motivation and behavior, we conducted the first systematical synthesis of FTP relationships in three crucial life domains. Our meta-analyses of FTP studies in education (k = 28), work (k = 17), and health (k = 32) involved N = 31,558 participants, and used a conceptual model for grouping FTP constructs. To address different outcome types, we applied the Theory of Planned Behavior when coding the studies. FTP relationships with outcomes were small-to-medium, were generalizable across domains, and were strongest when the FTP construct included a mixture of cognition, behavioral intention, and affect and, in education, when the FTP measure was domain specific rather than general. There were cross-cultural differences in FTP-outcome relationships. The strength of the FTP-outcome types relationship varied for attitudes, perceived behavioral control, behavioral intention, and behaviors. The lowest effect sizes were found for FTP predicting actual behaviors in education, work, and health and between FTP and health attitudes. Theoretical implications of the findings and future research directions are discussed. PMID:29364917

  3. Meta-analysis for quantitative microbiological risk assessments and benchmarking data

    NARCIS (Netherlands)

    Besten, den H.M.W.; Zwietering, M.H.

    2012-01-01

    Meta-analysis studies are increasingly being conducted in the food microbiology area to quantitatively integrate the findings of many individual studies on specific questions or kinetic parameters of interest. Meta-analyses provide global estimates of parameters and quantify their variabilities, and

  4. Systematic review with meta-analysis

    DEFF Research Database (Denmark)

    Kimer, N; Krag, A; Møller, Søren

    2014-01-01

    BACKGROUND: Rifaximin is recommended for prevention of hepatic encephalopathy (HE). The effects of rifaximin on overt and minimal HE are debated. AIM: To perform a systematic review and meta-analysis of randomised controlled trials (RCTs) on rifaximin for HE. METHODS: We performed electronic...... and manual searches, gathered information from the U.S. Food and Drug Administration Home Page, and obtained unpublished information on trial design and outcome measures from authors and pharmaceutical companies. Meta-analyses were performed and results presented as risk ratios (RR) with 95% confidence...

  5. Using structural equation modeling for network meta-analysis.

    Science.gov (United States)

    Tu, Yu-Kang; Wu, Yun-Chun

    2017-07-14

    Network meta-analysis overcomes the limitations of traditional pair-wise meta-analysis by incorporating all available evidence into a general statistical framework for simultaneous comparisons of several treatments. Currently, network meta-analyses are undertaken either within the Bayesian hierarchical linear models or frequentist generalized linear mixed models. Structural equation modeling (SEM) is a statistical method originally developed for modeling causal relations among observed and latent variables. As random effect is explicitly modeled as a latent variable in SEM, it is very flexible for analysts to specify complex random effect structure and to make linear and nonlinear constraints on parameters. The aim of this article is to show how to undertake a network meta-analysis within the statistical framework of SEM. We used an example dataset to demonstrate the standard fixed and random effect network meta-analysis models can be easily implemented in SEM. It contains results of 26 studies that directly compared three treatment groups A, B and C for prevention of first bleeding in patients with liver cirrhosis. We also showed that a new approach to network meta-analysis based on the technique of unrestricted weighted least squares (UWLS) method can also be undertaken using SEM. For both the fixed and random effect network meta-analysis, SEM yielded similar coefficients and confidence intervals to those reported in the previous literature. The point estimates of two UWLS models were identical to those in the fixed effect model but the confidence intervals were greater. This is consistent with results from the traditional pairwise meta-analyses. Comparing to UWLS model with common variance adjusted factor, UWLS model with unique variance adjusted factor has greater confidence intervals when the heterogeneity was larger in the pairwise comparison. The UWLS model with unique variance adjusted factor reflects the difference in heterogeneity within each comparison

  6. Genome-wide Meta-analyses of Breast, Ovarian and Prostate Cancer Association Studies Identify Multiple New Susceptibility Loci Shared by At Least Two Cancer Types

    Science.gov (United States)

    Kar, Siddhartha P.; Beesley, Jonathan; Al Olama, Ali Amin; Michailidou, Kyriaki; Tyrer, Jonathan; Kote-Jarai, ZSofia; Lawrenson, Kate; Lindstrom, Sara; Ramus, Susan J.; Thompson, Deborah J.; Kibel, Adam S.; Dansonka-Mieszkowska, Agnieszka; Michael, Agnieszka; Dieffenbach, Aida K.; Gentry-Maharaj, Aleksandra; Whittemore, Alice S.; Wolk, Alicja; Monteiro, Alvaro; Peixoto, Ana; Kierzek, Andrzej; Cox, Angela; Rudolph, Anja; Gonzalez-Neira, Anna; Wu, Anna H.; Lindblom, Annika; Swerdlow, Anthony; Ziogas, Argyrios; Ekici, Arif B.; Burwinkel, Barbara; Karlan, Beth Y.; Nordestgaard, Børge G.; Blomqvist, Carl; Phelan, Catherine; McLean, Catriona; Pearce, Celeste Leigh; Vachon, Celine; Cybulski, Cezary; Slavov, Chavdar; Stegmaier, Christa; Maier, Christiane; Ambrosone, Christine B.; Høgdall, Claus K.; Teerlink, Craig C.; Kang, Daehee; Tessier, Daniel C.; Schaid, Daniel J.; Stram, Daniel O.; Cramer, Daniel W.; Neal, David E.; Eccles, Diana; Flesch-Janys, Dieter; Velez Edwards, Digna R.; Wokozorczyk, Dominika; Levine, Douglas A.; Yannoukakos, Drakoulis; Sawyer, Elinor J.; Bandera, Elisa V.; Poole, Elizabeth M.; Goode, Ellen L.; Khusnutdinova, Elza; Høgdall, Estrid; Song, Fengju; Bruinsma, Fiona; Heitz, Florian; Modugno, Francesmary; Hamdy, Freddie C.; Wiklund, Fredrik; Giles, Graham G.; Olsson, Håkan; Wildiers, Hans; Ulmer, Hans-Ulrich; Pandha, Hardev; Risch, Harvey A.; Darabi, Hatef; Salvesen, Helga B.; Nevanlinna, Heli; Gronberg, Henrik; Brenner, Hermann; Brauch, Hiltrud; Anton-Culver, Hoda; Song, Honglin; Lim, Hui-Yi; McNeish, Iain; Campbell, Ian; Vergote, Ignace; Gronwald, Jacek; Lubiński, Jan; Stanford, Janet L.; Benítez, Javier; Doherty, Jennifer A.; Permuth, Jennifer B.; Chang-Claude, Jenny; Donovan, Jenny L.; Dennis, Joe; Schildkraut, Joellen M.; Schleutker, Johanna; Hopper, John L.; Kupryjanczyk, Jolanta; Park, Jong Y.; Figueroa, Jonine; Clements, Judith A.; Knight, Julia A.; Peto, Julian; Cunningham, Julie M.; Pow-Sang, Julio; Batra, Jyotsna; Czene, Kamila; Lu, Karen H.; Herkommer, Kathleen; Khaw, Kay-Tee; Matsuo, Keitaro; Muir, Kenneth; Offitt, Kenneth; Chen, Kexin; Moysich, Kirsten B.; Aittomäki, Kristiina; Odunsi, Kunle; Kiemeney, Lambertus A.; Massuger, Leon F.A.G.; Fitzgerald, Liesel M.; Cook, Linda S.; Cannon-Albright, Lisa; Hooning, Maartje J.; Pike, Malcolm C.; Bolla, Manjeet K.; Luedeke, Manuel; Teixeira, Manuel R.; Goodman, Marc T.; Schmidt, Marjanka K.; Riggan, Marjorie; Aly, Markus; Rossing, Mary Anne; Beckmann, Matthias W.; Moisse, Matthieu; Sanderson, Maureen; Southey, Melissa C.; Jones, Michael; Lush, Michael; Hildebrandt, Michelle A. T.; Hou, Ming-Feng; Schoemaker, Minouk J.; Garcia-Closas, Montserrat; Bogdanova, Natalia; Rahman, Nazneen; Le, Nhu D.; Orr, Nick; Wentzensen, Nicolas; Pashayan, Nora; Peterlongo, Paolo; Guénel, Pascal; Brennan, Paul; Paulo, Paula; Webb, Penelope M.; Broberg, Per; Fasching, Peter A.; Devilee, Peter; Wang, Qin; Cai, Qiuyin; Li, Qiyuan; Kaneva, Radka; Butzow, Ralf; Kopperud, Reidun Kristin; Schmutzler, Rita K.; Stephenson, Robert A.; MacInnis, Robert J.; Hoover, Robert N.; Winqvist, Robert; Ness, Roberta; Milne, Roger L.; Travis, Ruth C.; Benlloch, Sara; Olson, Sara H.; McDonnell, Shannon K.; Tworoger, Shelley S.; Maia, Sofia; Berndt, Sonja; Lee, Soo Chin; Teo, Soo-Hwang; Thibodeau, Stephen N.; Bojesen, Stig E.; Gapstur, Susan M.; Kjær, Susanne Krüger; Pejovic, Tanja; Tammela, Teuvo L.J.; Dörk, Thilo; Brüning, Thomas; Wahlfors, Tiina; Key, Tim J.; Edwards, Todd L.; Menon, Usha; Hamann, Ute; Mitev, Vanio; Kosma, Veli-Matti; Setiawan, Veronica Wendy; Kristensen, Vessela; Arndt, Volker; Vogel, Walther; Zheng, Wei; Sieh, Weiva; Blot, William J.; Kluzniak, Wojciech; Shu, Xiao-Ou; Gao, Yu-Tang; Schumacher, Fredrick; Freedman, Matthew L.; Berchuck, Andrew; Dunning, Alison M.; Simard, Jacques; Haiman, Christopher A.; Spurdle, Amanda; Sellers, Thomas A.; Hunter, David J.; Henderson, Brian E.; Kraft, Peter; Chanock, Stephen J.; Couch, Fergus J.; Hall, Per; Gayther, Simon A.; Easton, Douglas F.; Chenevix-Trench, Georgia; Eeles, Rosalind; Pharoah, Paul D.P.; Lambrechts, Diether

    2016-01-01

    Breast, ovarian, and prostate cancers are hormone-related and may have a shared genetic basis but this has not been investigated systematically by genome-wide association (GWA) studies. Meta-analyses combining the largest GWA meta-analysis data sets for these cancers totaling 112,349 cases and 116,421 controls of European ancestry, all together and in pairs, identified at P cancer loci: three associated with susceptibility to all three cancers (rs17041869/2q13/BCL2L11; rs7937840/11q12/INCENP; rs1469713/19p13/GATAD2A), two breast and ovarian cancer risk loci (rs200182588/9q31/SMC2; rs8037137/15q26/RCCD1), and two breast and prostate cancer risk loci (rs5013329/1p34/NSUN4; rs9375701/6q23/L3MBTL3). Index variants in five additional regions previously associated with only one cancer also showed clear association with a second cancer type. Cell-type specific expression quantitative trait locus and enhancer-gene interaction annotations suggested target genes with potential cross-cancer roles at the new loci. Pathway analysis revealed significant enrichment of death receptor signaling genes near loci with P cancer meta-analysis. PMID:27432226

  7. Project W-320 SAR and process control thermal analyses

    International Nuclear Information System (INIS)

    Sathyanarayana, K.

    1997-01-01

    This report summarizes the results of thermal hydraulic computer modeling supporting Project W-320 for process control and SAR documentation. Parametric analyses were performed for the maximum steady state waste temperature. The parameters included heat load distribution, tank heat load, fluffing factor and thermal conductivity. Uncertainties in the fluffing factor and heat load distribution had the largest effect on maximum waste temperature. Safety analyses were performed for off normal events including loss of ventilation, loss of evaporation and loss of secondary chiller. The loss of both the primary and secondary ventilation was found to be the most limiting event with saturation temperature in the bottom waste reaching in just over 30 days. An evaluation was performed for the potential lowering of the supernatant level in tank 241-AY-102. The evaluation included a loss of ventilation and steam bump analysis. The reduced supernatant level decreased the time to reach saturation temperature in the waste for the loss of ventilation by about one week. However, the consequence of a steam bump were dramatically reduced

  8. A Meta-Analysis of Local Climate Change Adaptation Actions ...

    Science.gov (United States)

    Local governments are beginning to take steps to address the consequences of climate change, such as sea level rise and heat events. However, we do not have a clear understanding of what local governments are doing -- the extent to which they expect climate change to affect their community, the types of actions they have in place to address climate change, and the resources at their disposal for implementation. Several studies have been conducted by academics, non-governmental organizations, and public agencies to assess the status of local climate change adaptation. This project collates the findings from dozens of such studies to conduct a meta-analysis of local climate change adaptation actions. The studies will be characterized along several dimensions, including (a) methods used, (b) timing and geographic scope, (c) topics covered, (d) types of adaptation actions identified, (e) implementation status, and (f) public engagement and environmental justice dimensions considered. The poster presents the project's rationale and approach and some illustrative findings from early analyses. [Note: The document being reviewed is an abstract in which a poster is being proposed. The poster will enter clearance if the abstract is accepted] The purpose of this poster is to present the research framework and approaches I am developing for my ORISE postdoctoral project, and to get feedback on early analyses.

  9. Genotype Imputation for Latinos Using the HapMap and 1000 Genomes Project Reference Panels

    Directory of Open Access Journals (Sweden)

    Xiaoyi eGao

    2012-06-01

    Full Text Available Genotype imputation is a vital tool in genome-wide association studies (GWAS and meta-analyses of multiple GWAS results. Imputation enables researchers to increase genomic coverage and to pool data generated using different genotyping platforms. HapMap samples are often employed as the reference panel. More recently, the 1000 Genomes Project resource is becoming the primary source for reference panels. Multiple GWAS and meta-analyses are targeting Latinos, the most populous and fastest growing minority group in the US. However, genotype imputation resources for Latinos are rather limited compared to individuals of European ancestry at present, largely because of the lack of good reference data. One choice of reference panel for Latinos is one derived from the population of Mexican individuals in Los Angeles contained in the HapMap Phase 3 project and the 1000 Genomes Project. However, a detailed evaluation of the quality of the imputed genotypes derived from the public reference panels has not yet been reported. Using simulation studies, the Illumina OmniExpress GWAS data from the Los Angles Latino Eye Study and the MACH software package, we evaluated the accuracy of genotype imputation in Latinos. Our results show that the 1000 Genomes Project AMR+CEU+YRI reference panel provides the highest imputation accuracy for Latinos, and that also including Asian samples in the panel can reduce imputation accuracy. We also provide the imputation accuracy for each autosomal chromosome using the 1000 Genomes Project panel for Latinos. Our results serve as a guide to future imputation-based analysis in Latinos.

  10. Efficacy of cryotherapy for the treatment of cutaneous leishmaniasis: meta-analyses of clinical trials.

    Science.gov (United States)

    López-Carvajal, Liliana; Cardona-Arias, Jaiberth Antonio; Zapata-Cardona, María Isabel; Sánchez-Giraldo, Vanesa; Vélez, Iván Darío

    2016-07-26

    Cryotherapy is a local treatment for cutaneous leishmaniasis with variable efficacy and greater safety than conventional treatment. The objective of this study is to evaluate the efficacy and safety of cryotherapy for the treatment of cutaneous leishmaniasis and to compare it with pentavalent antimonials. A meta-analysis based on a search of nine databases with eight strategies was conducted. Inclusion and exclusion criteria were applied, the methodological quality of each article was evaluated, and the reproducibility of the study selection and information extraction from each clinical trial was assured. The per lesion and per patient efficacy was calculated, and a meta-analysis of relative risks with the random effects model and the Dersimonian and Laird's, Begg, and Egger tests, along with a sensitivity analysis, were performed. A meta-regression based on the methodological quality of the trials included was also performed. Eight studies were included in which respective per lesion efficacies of 67.3 % and 67.7 % were reported for cryotherapy and pentavalent antimonials. In 271 patients treated with cryotherapy and in 199 with pentavalent antimonials, respective per protocol and intent to treat efficacies of 63.6 % and 54.2 % were found in the first group, and per protocol and intent to treat efficacies of 74.7 % and 68.3 % were found in the second group. The relative risk for the comparison of efficacy in the two groups was 0.73 (0.42-1.29). The results of the sensitivity analysis and the meta-regression analysis of relative risks were statistically equal to the overall results. This investigation provides evidence in favor of the use of cryotherapy given that its efficacy is similar to that of pentavalent antimonials.

  11. Simpson's paradox visualized: The example of the Rosiglitazone meta-analysis

    Directory of Open Access Journals (Sweden)

    Schumacher Martin

    2008-05-01

    Full Text Available Abstract Background Simpson's paradox is sometimes referred to in the areas of epidemiology and clinical research. It can also be found in meta-analysis of randomized clinical trials. However, though readers are able to recalculate examples from hypothetical as well as real data, they may have problems to easily figure where it emerges from. Method First, two kinds of plots are proposed to illustrate the phenomenon graphically, a scatter plot and a line graph. Subsequently, these can be overlaid, resulting in a overlay plot. The plots are applied to the recent large meta-analysis of adverse effects of rosiglitazone on myocardial infarction and to an example from the literature. A large set of meta-analyses is screened for further examples. Results As noted earlier by others, occurrence of Simpson's paradox in the meta-analytic setting, if present, is associated with imbalance of treatment arm size. This is well illustrated by the proposed plots. The rosiglitazone meta-analysis shows an effect reversion if all trials are pooled. In a sample of 157 meta-analyses, nine showed an effect reversion after pooling, though non-significant in all cases. Conclusion The plots give insight on how the imbalance of trial arm size works as a confounder, thus producing Simpson's paradox. Readers can see why meta-analytic methods must be used and what is wrong with simple pooling.

  12. Are Youth Psychopathic Traits Related to Bullying? Meta-analyses on Callous-Unemotional Traits, Narcissism, and Impulsivity.

    Science.gov (United States)

    van Geel, Mitch; Toprak, Fatih; Goemans, Anouk; Zwaanswijk, Wendy; Vedder, Paul

    2017-10-01

    In the current manuscript meta-analyses are performed to analyze the relations between three aspects of psychopathy in youth, Callous-Unemotional (CU) traits, Narcissism, and Impulsivity, and bullying behaviors. The databases PsycINFO, MEDLINE, ERIC, Web of Science and Proquest were searched for relevant articles on bullying and CU traits, Narcissism, or Impulsivity in youth under 20 years of age. Two authors each independently screened 842 studies that were found in the literature search. Two authors independently coded ten studies on bullying and CU (N = 4115) traits, six studies on bullying and Narcissism (N = 3376) and 14 studies on bullying and Impulsivity (N = 33,574) that met the inclusion criteria. Significant correlations were found between bullying and CU traits, Narcissism, and Impulsivity. These results were not affected by publication bias. Anti-bullying interventions could potentially benefit from including elements that have been found effective in the treatment of youth psychopathy.

  13. An overview of meta-analysis for clinicians

    Science.gov (United States)

    Lee, Young Ho

    2018-01-01

    The number of medical studies being published is increasing exponentially, and clinicians must routinely process large amounts of new information. Moreover, the results of individual studies are often insufficient to provide confident answers, as their results are not consistently reproducible. A meta-analysis is a statistical method for combining the results of different studies on the same topic and it may resolve conflicts among studies. Meta-analysis is being used increasingly and plays an important role in medical research. This review introduces the basic concepts, steps, advantages, and caveats of meta-analysis, to help clinicians understand it in clinical practice and research. A major advantage of a meta-analysis is that it produces a precise estimate of the effect size, with considerably increased statistical power, which is important when the power of the primary study is limited because of a small sample size. A meta-analysis may yield conclusive results when individual studies are inconclusive. Furthermore, meta-analyses investigate the source of variation and different effects among subgroups. In summary, a meta-analysis is an objective, quantitative method that provides less biased estimates on a specific topic. Understanding how to conduct a meta-analysis aids clinicians in the process of making clinical decisions. PMID:29277096

  14. An overview of meta-analysis for clinicians.

    Science.gov (United States)

    Lee, Young Ho

    2018-03-01

    The number of medical studies being published is increasing exponentially, and clinicians must routinely process large amounts of new information. Moreover, the results of individual studies are often insufficient to provide confident answers, as their results are not consistently reproducible. A meta-analysis is a statistical method for combining the results of different studies on the same topic and it may resolve conflicts among studies. Meta-analysis is being used increasingly and plays an important role in medical research. This review introduces the basic concepts, steps, advantages, and caveats of meta-analysis, to help clinicians understand it in clinical practice and research. A major advantage of a meta-analysis is that it produces a precise estimate of the effect size, with considerably increased statistical power, which is important when the power of the primary study is limited because of a small sample size. A meta-analysis may yield conclusive results when individual studies are inconclusive. Furthermore, meta-analyses investigate the source of variation and different effects among subgroups. In summary, a meta-analysis is an objective, quantitative method that provides less biased estimates on a specific topic. Understanding how to conduct a meta-analysis aids clinicians in the process of making clinical decisions.

  15. Multi-Role Project (MRP): A New Project-Based Learning Method for STEM

    Science.gov (United States)

    Warin, Bruno; Talbi, Omar; Kolski, Christophe; Hoogstoel, Frédéric

    2016-01-01

    This paper presents the "Multi-Role Project" method (MRP), a broadly applicable project-based learning method, and describes its implementation and evaluation in the context of a Science, Technology, Engineering, and Mathematics (STEM) course. The MRP method is designed around a meta-principle that considers the project learning activity…

  16. Parents’ experiences of neonatal transfer. A meta-study of qualitative research 2000-2017

    DEFF Research Database (Denmark)

    Aagaard, Hanne; Hall, Elisabeth; Ludvigsen, Mette Spliid

    2018-01-01

    Transfers of critically ill neonates are frequent phenomena. Even though parents’ par- ticipation is regarded as crucial in neonatal care, a transfer often means that parents and neonates are separated. A systematic review of the parents’ experiences of neo- natal transfer is lacking. This paper ...... identified ‘wavering and wandering’ as a metaphoric representation of the parents’ experiences. The findings add knowledge about meta- study as an approach for com- prehensive qualitative research and point at the value of meta- theory and meta- method analyses....... describes a meta- study addressing qualitative re- search about parents’ experiences of neonatal transfer. Through deconstruction and reflections of theories, methods, and empirical data, the aim was to achieve a deeper understanding of theoretical, empirical, contextual, historical, and methodological is......- sues of qualitative studies concerning parents’ experiences of neonatal transfer over the course of this meta- study (2000–2017). Meta- theory and meta- method analyses showed that caring, transition, and family- centered care were main theoretical frames applied and that interviewing with a small...

  17. The Genomes OnLine Database (GOLD) v.5: a metadata management system based on a four level (meta)genome project classification

    Science.gov (United States)

    Reddy, T.B.K.; Thomas, Alex D.; Stamatis, Dimitri; Bertsch, Jon; Isbandi, Michelle; Jansson, Jakob; Mallajosyula, Jyothi; Pagani, Ioanna; Lobos, Elizabeth A.; Kyrpides, Nikos C.

    2015-01-01

    The Genomes OnLine Database (GOLD; http://www.genomesonline.org) is a comprehensive online resource to catalog and monitor genetic studies worldwide. GOLD provides up-to-date status on complete and ongoing sequencing projects along with a broad array of curated metadata. Here we report version 5 (v.5) of the database. The newly designed database schema and web user interface supports several new features including the implementation of a four level (meta)genome project classification system and a simplified intuitive web interface to access reports and launch search tools. The database currently hosts information for about 19 200 studies, 56 000 Biosamples, 56 000 sequencing projects and 39 400 analysis projects. More than just a catalog of worldwide genome projects, GOLD is a manually curated, quality-controlled metadata warehouse. The problems encountered in integrating disparate and varying quality data into GOLD are briefly highlighted. GOLD fully supports and follows the Genomic Standards Consortium (GSC) Minimum Information standards. PMID:25348402

  18. The Genomes OnLine Database (GOLD) v.5: a metadata management system based on a four level (meta)genome project classification

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Tatiparthi B. K. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Thomas, Alex D. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Stamatis, Dimitri [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Bertsch, Jon [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Isbandi, Michelle [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Jansson, Jakob [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Mallajosyula, Jyothi [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Pagani, Ioanna [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Lobos, Elizabeth A. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); Kyrpides, Nikos C. [USDOE Joint Genome Institute (JGI), Walnut Creek, CA (United States); King Abdulaziz Univ., Jeddah (Saudi Arabia)

    2014-10-27

    The Genomes OnLine Database (GOLD; http://www.genomesonline.org) is a comprehensive online resource to catalog and monitor genetic studies worldwide. GOLD provides up-to-date status on complete and ongoing sequencing projects along with a broad array of curated metadata. Within this paper, we report version 5 (v.5) of the database. The newly designed database schema and web user interface supports several new features including the implementation of a four level (meta)genome project classification system and a simplified intuitive web interface to access reports and launch search tools. The database currently hosts information for about 19 200 studies, 56 000 Biosamples, 56 000 sequencing projects and 39 400 analysis projects. More than just a catalog of worldwide genome projects, GOLD is a manually curated, quality-controlled metadata warehouse. The problems encountered in integrating disparate and varying quality data into GOLD are briefly highlighted. Lastly, GOLD fully supports and follows the Genomic Standards Consortium (GSC) Minimum Information standards.

  19. Poor prognostic value of the modified Mallampati score: a meta-analysis involving 177 088 patients

    DEFF Research Database (Denmark)

    Lundstrøm, L H; Vester-Andersen, M; Møller, Ann

    2011-01-01

    searches. The pooled estimates from the meta-analyses were calculated based on a random-effects model and a summary receiver operating curve. Meta-regression analyses were performed to explore sources of possible heterogeneity between the studies. The summary receiver operating curve demonstrated an area...

  20. Meta-analysis for genome-wide association studies using case-control design: application and practice.

    Science.gov (United States)

    Shim, Sungryul; Kim, Jiyoung; Jung, Wonguen; Shin, In-Soo; Bae, Jong-Myon

    2016-01-01

    This review aimed to arrange the process of a systematic review of genome-wide association studies in order to practice and apply a genome-wide meta-analysis (GWMA). The process has a series of five steps: searching and selection, extraction of related information, evaluation of validity, meta-analysis by type of genetic model, and evaluation of heterogeneity. In contrast to intervention meta-analyses, GWMA has to evaluate the Hardy-Weinberg equilibrium (HWE) in the third step and conduct meta-analyses by five potential genetic models, including dominant, recessive, homozygote contrast, heterozygote contrast, and allelic contrast in the fourth step. The 'genhwcci' and 'metan' commands of STATA software evaluate the HWE and calculate a summary effect size, respectively. A meta-regression using the 'metareg' command of STATA should be conducted to evaluate related factors of heterogeneities.

  1. A hierarchy of patient-reported outcome measures for meta-analysis of knee osteoarthritis trials

    DEFF Research Database (Denmark)

    Juhl, Carsten Bogh; Lund, Hans; Guyatt, GH

    2010-01-01

    Title A hierarchy of patient-reported outcome measures for meta-analysis of knee osteoarthritis trials: empirical evidence from a survey of high impact journals Objective To develop a prioritized list for extracting patient-reported outcomes (PROs) measuring pain and disability for meta-analyses ......Title A hierarchy of patient-reported outcome measures for meta-analysis of knee osteoarthritis trials: empirical evidence from a survey of high impact journals Objective To develop a prioritized list for extracting patient-reported outcomes (PROs) measuring pain and disability for meta...... composite disability scores. Conclusions As choosing the most favorable PROs from individual trials can overestimate the effect compared to a systematic approach, using a prioritized list as presented in this study is recommended to reduce reviewer's likelihood of biased selection of PROs in meta-analyses....

  2. Effects οf Yoga οn cancer patients: Secondary analysis οf Systematic Reviews/Meta-Analyses

    Directory of Open Access Journals (Sweden)

    Dimos Mastrogiannis

    2016-09-01

    Full Text Available Introduction: Western medicine’s model has been enriched with alternative management and treatment methods. Yoga is a technique that incorporates physical exercises, breathing methods, meditation and relaxation which has been proposed to have positive effects on cancer patients. Aim: The aim of the present study is to critically review findings of systematic reviews/meta-analyses that are available in the international literature, regarding the effects of yoga on cancer patients. Methodology: Literature review was performed in five (5 databases: PubMed, Scopus, EMBASE, Web of Science and Cochrane Database of systematic Reviews. Authors adopted the Preferred Reporting Items for Systematic Reviews and Meta-Analysis model in order to perform a critical review of the existing literature. Methodological assessment of papers under review was performed according to criteria of the Assessment of Multiple Systematic Reviews instrument. Inclusion criteria were the English language, research undertaken in adults and evaluation of effects of yoga as the primary intervention. Results: Although there is a lack of guidelines regarding the assessment of systematic reviews using the above mentioned instruments, 16 papers were included in the present study. Findings are confounding, even though there is evidence supporting the use of yoga in certain types of cancer. Specifically, improvements in quality of life and psychological wellbeing, anxiety, however, not pain reduction, have been reported in women suffering from breast cancer, however, no statistically significant effect has been documented in patients with haematological malignancies. Conclusions: The majority of studies about the effects of yoga on quality of life, fatigue, sleep quality, anxiety, and depression have small samples. There is a trend towards an overall quality of life improvement, nonetheless, the lack of sufficiently powered randomized controlled trials prevents the extraction of a safe

  3. Bisphenol-A exposures and behavioural aberrations: median and linear spline and meta-regression analyses of 12 toxicity studies in rodents.

    Science.gov (United States)

    Peluso, Marco E M; Munnia, Armelle; Ceppi, Marcello

    2014-11-05

    Exposures to bisphenol-A, a weak estrogenic chemical, largely used for the production of plastic containers, can affect the rodent behaviour. Thus, we examined the relationships between bisphenol-A and the anxiety-like behaviour, spatial skills, and aggressiveness, in 12 toxicity studies of rodent offspring from females orally exposed to bisphenol-A, while pregnant and/or lactating, by median and linear splines analyses. Subsequently, the meta-regression analysis was applied to quantify the behavioural changes. U-shaped, inverted U-shaped and J-shaped dose-response curves were found to describe the relationships between bisphenol-A with the behavioural outcomes. The occurrence of anxiogenic-like effects and spatial skill changes displayed U-shaped and inverted U-shaped curves, respectively, providing examples of effects that are observed at low-doses. Conversely, a J-dose-response relationship was observed for aggressiveness. When the proportion of rodents expressing certain traits or the time that they employed to manifest an attitude was analysed, the meta-regression indicated that a borderline significant increment of anxiogenic-like effects was present at low-doses regardless of sexes (β)=-0.8%, 95% C.I. -1.7/0.1, P=0.076, at ≤120 μg bisphenol-A. Whereas, only bisphenol-A-males exhibited a significant inhibition of spatial skills (β)=0.7%, 95% C.I. 0.2/1.2, P=0.004, at ≤100 μg/day. A significant increment of aggressiveness was observed in both the sexes (β)=67.9,C.I. 3.4, 172.5, P=0.038, at >4.0 μg. Then, bisphenol-A treatments significantly abrogated spatial learning and ability in males (Pbisphenol-A, e.g. ≤120 μg/day, were associated to behavioural aberrations in offspring. Copyright © 2014. Published by Elsevier Ireland Ltd.

  4. Coordinate based random effect size meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Tench, C R; Tanasescu, Radu; Constantinescu, C S; Auer, D P; Cottam, W J

    2017-06-01

    Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Values of natural and human-made wetlands: A meta-analysis

    NARCIS (Netherlands)

    Ghermandi, A.; van den Bergh, J.C.J.M.; Brander, L.M.; de Groot, H.L.F.; Nunes, P.A.L.D.

    2010-01-01

    The values of goods and services provided by wetland ecosystems are examined through a meta-analysis of an expanded database of wetland value estimates and with a focus on human-made wetlands. This study extends and improves upon previous meta-analyses of the wetland valuation literature in terms of

  6. Citation Discovery Tools for Conducting Adaptive Meta-analyses to Update Systematic Reviews.

    Science.gov (United States)

    Bae, Jong-Myon; Kim, Eun Hee

    2016-03-01

    The systematic review (SR) is a research methodology that aims to synthesize related evidence. Updating previously conducted SRs is necessary when new evidence has been produced, but no consensus has yet emerged on the appropriate update methodology. The authors have developed a new SR update method called 'adaptive meta-analysis' (AMA) using the 'cited by', 'similar articles', and 'related articles' citation discovery tools in the PubMed and Scopus databases. This study evaluates the usefulness of these citation discovery tools for updating SRs. Lists were constructed by applying the citation discovery tools in the two databases to the articles analyzed by a published SR. The degree of overlap between the lists and distribution of excluded results were evaluated. The articles ultimately selected for the SR update meta-analysis were found in the lists obtained from the 'cited by' and 'similar' tools in PubMed. Most of the selected articles appeared in both the 'cited by' lists in Scopus and PubMed. The Scopus 'related' tool did not identify the appropriate articles. The AMA, which involves using both citation discovery tools in PubMed, and optionally, the 'related' tool in Scopus, was found to be useful for updating an SR.

  7. Parents' experiences of neonatal transfer. A meta-study of qualitative research 2000-2017.

    Science.gov (United States)

    Aagaard, Hanne; Hall, Elisabeth O C; Ludvigsen, Mette S; Uhrenfeldt, Lisbeth; Fegran, Liv

    2018-02-15

    Transfers of critically ill neonates are frequent phenomena. Even though parents' participation is regarded as crucial in neonatal care, a transfer often means that parents and neonates are separated. A systematic review of the parents' experiences of neonatal transfer is lacking. This paper describes a meta-study addressing qualitative research about parents' experiences of neonatal transfer. Through deconstruction and reflections of theories, methods, and empirical data, the aim was to achieve a deeper understanding of theoretical, empirical, contextual, historical, and methodological issues of qualitative studies concerning parents' experiences of neonatal transfer over the course of this meta-study (2000-2017). Meta-theory and meta-method analyses showed that caring, transition, and family-centered care were main theoretical frames applied and that interviewing with a small number of participants was the preferred data collection method. The meta-data-analysis showed that transfer was a scary, unfamiliar, and threatening experience for the parents; they were losing familiar context, were separated from their neonate, and could feel their parenthood disrupted. We identified 'wavering and wandering' as a metaphoric representation of the parents' experiences. The findings add knowledge about meta-study as an approach for comprehensive qualitative research and point at the value of meta-theory and meta-method analyses. © 2018 John Wiley & Sons Ltd.

  8. Things I Have Learned about Meta-Analysis Since 1990: Reducing Bias in Search of “The Big Picture” / Ce que j’ai appris sur la méta-analyse depuis 1990 : réduire les partis pris en quête d’une vue d’ensemble

    Directory of Open Access Journals (Sweden)

    Robert M Bernard

    2014-12-01

    Full Text Available This paper examines sources of potential bias in systematic reviews and meta-analyses which can distort their findings, leading to problems with interpretation and application by practitioners and policymakers. It follows from an article that was published in the Canadian Journal of Communication in 1990, “Integrating Research into Instructional Practice: The Use and Abuse of Meta-analysis,” which introduced meta-analysis as a means for estimating population parameters and summarizing quantitative research around instructional research questions. This paper begins by examining two cases where multiple meta-analyses disagree. It then goes on to describe substantive and methodological aspects of meta-analysis where various kinds of bias can influence the outcomes and suggests measures that can be taken to avoid them. The intention is to improve the reliability and accuracy of reviews so that practitioners can trust the results and use them more effectively. Cet article examine les sources des partis pris potentiels dans les synthèses systématiques et les méta-analyses qui peuvent déformer les conclusions, ce qui peut causer des problèmes d’interprétation et d’application par les praticiens et les responsables des politiques. Il fait suite à un article publié dans le Canadian Journal of Communication en 1990, intitulé « Integrating Research into Instructional Practice: The Use and Abuse of Meta-analysis », qui présentait la méta-analyse comme moyen d’estimer les paramètres relatifs à la population et de résumer la recherche quantitative sur les questions de recherche pédagogique. L’article commence avec l’examen de deux cas dans lesquels de nombreuses méta-analyses sont en désaccord. Il décrit ensuite les aspects substantifs et méthodologiques des méta-analyses dans lesquels divers types de partis pris peuvent influencer les résultats et suggère des mesures qui peuvent être adoptées pour éviter ces partis

  9. Metaprop: a Stata command to perform meta-analysis of binomial data.

    Science.gov (United States)

    Nyaga, Victoria N; Arbyn, Marc; Aerts, Marc

    2014-01-01

    Meta-analyses have become an essential tool in synthesizing evidence on clinical and epidemiological questions derived from a multitude of similar studies assessing the particular issue. Appropriate and accessible statistical software is needed to produce the summary statistic of interest. Metaprop is a statistical program implemented to perform meta-analyses of proportions in Stata. It builds further on the existing Stata procedure metan which is typically used to pool effects (risk ratios, odds ratios, differences of risks or means) but which is also used to pool proportions. Metaprop implements procedures which are specific to binomial data and allows computation of exact binomial and score test-based confidence intervals. It provides appropriate methods for dealing with proportions close to or at the margins where the normal approximation procedures often break down, by use of the binomial distribution to model the within-study variability or by allowing Freeman-Tukey double arcsine transformation to stabilize the variances. Metaprop was applied on two published meta-analyses: 1) prevalence of HPV-infection in women with a Pap smear showing ASC-US; 2) cure rate after treatment for cervical precancer using cold coagulation. The first meta-analysis showed a pooled HPV-prevalence of 43% (95% CI: 38%-48%). In the second meta-analysis, the pooled percentage of cured women was 94% (95% CI: 86%-97%). By using metaprop, no studies with 0% or 100% proportions were excluded from the meta-analysis. Furthermore, study specific and pooled confidence intervals always were within admissible values, contrary to the original publication, where metan was used.

  10. Clinical benefit, complication patterns and cost effectiveness of laser in situ keratomileusis (LASIK) in moderate myopia: results of independent meta analyses on clinical outcome and postoperative complication profiles.

    Science.gov (United States)

    Lamparter, J; Dick, H B; Krummenauer, Frank

    2005-09-12

    Laser in situ keratomileusis (LASIK) means a patient investment of 2426 Euro per eye, which usually cannot be funded by European health care insurers. In the context of recent resource allocation discussions, however, the cost effectiveness of LASIK could become an important indication of allocation decisions. Therefore an evidence based estimation of its incremental cost effectiveness was intended. Three independent meta analyses were implemented to estimate the refractive gain (dpt) due to conventional LASIK procedures as well as the predictability of the latter (%) (fraction of eyes achieving a postoperative refraction with maximum deviation of +/- 0.5 dpt from the target refraction). Study reports of 1995 - 2004 (English or German language) were screened for appropriate key words. Meta effects in refractive gain and predictability were estimated by means and standard deviations of reported effect measures. Cost data were estimated by German DRG rates and individual clinical pathway calculations; cost effectiveness was then computed in terms of the incremental cost effectiveness ratio (ICER) for both clinical benefit endpoints. A sensitivity analysis comprised cost variations of +/- 10 % and utility variations alongside the meta effects' 95% confidence intervals. Total direct costs from the patients' perspective were estimated at 2426 Euro per eye, associated with a refractive meta benefit of 5.93 dpt (95% meta confidence interval 5.32 - 6.54 dpt) and a meta predictability of 67% (43% - 91%). In terms of incremental costs, the unilateral LASIK implied a patient investion of 409 Euro (sensitivity range 351 - 473 Euro) per gained refractive unit or 36 Euro (27 - 56 Euro) per gained percentage point in predictability. When LASIK associated complication patterns were considered, the total direct costs amounted up to 3075 Euro, resulting in incremental costs of 519 Euro / dpt (sensitivity range 445 - 600 Euro / dpt) or 46 Euro / % (34 - 72 Euro / %). Most frequently

  11. The MetaLex Document Server : Legal Documents as Versioned Linked Data

    NARCIS (Netherlands)

    Hoekstra, R.; Aroyo, L.; Welty, C.; Alani, H.; Taylor, J.; Bernstein, A.; Kagal, L.; Noy, N.; Blomqvist, E.

    2011-01-01

    This paper introduces the MetaLex Document Server (MDS), an ongoing project to improve access to legal sources (regulations, court rulings) by means of a generic legal XML syntax (CEN MetaLex) and Linked Data. The MDS defines a generic conversion mechanism from legacy legal XML syntaxes to CEN

  12. Meta-analysis for genome-wide association studies using case-control design: application and practice

    Directory of Open Access Journals (Sweden)

    Sungryul Shim

    2016-12-01

    Full Text Available This review aimed to arrange the process of a systematic review of genome-wide association studies in order to practice and apply a genome-wide meta-analysis (GWMA. The process has a series of five steps: searching and selection, extraction of related information, evaluation of validity, meta-analysis by type of genetic model, and evaluation of heterogeneity. In contrast to intervention meta-analyses, GWMA has to evaluate the Hardy–Weinberg equilibrium (HWE in the third step and conduct meta-analyses by five potential genetic models, including dominant, recessive, homozygote contrast, heterozygote contrast, and allelic contrast in the fourth step. The ‘genhwcci’ and ‘metan’ commands of STATA software evaluate the HWE and calculate a summary effect size, respectively. A meta-regression using the ‘metareg’ command of STATA should be conducted to evaluate related factors of heterogeneities.

  13. Periodontal disease severity in subjects with dementia: A systematic review and meta-analysis.

    Science.gov (United States)

    Gusman, David Jonathan R; Mello-Neto, João M; Alves, Breno Edson S; Matheus, Henrique R; Ervolino, Edilson; Theodoro, Letícia H; de Almeida, Juliano M

    Despite clinical trials and reviews attempt to assess a possible relationship between dementia and periodontal disease, no meta-analysis has been performed and this issue remains undetermined. The aim of this study is to conduct a systematic review and meta-analysis to assess severity of periodontitis in subjects with dementia. The search was conducted in Pubmed, Embase/MEDLINE. Two independent reviewers extracted data and assessed the risk bias (Newcastle-Ottawa scale). Meta-analyses were performed using the means of probing depth (PD) and clinical attachment loss (CAL) in patients with or without dementia. The mean difference were analyzed (P ≤ 0.05). Fourteen studies were included in the systematic review. In the qualitative analysis, most studies reported higher prevalence of periodontal disease in dementia patients. The studies had low risk of bias and two meta-analyses were performed for each parameter, including or not a cross-sectional study. The meta-analyses including the cross-sectional study demonstrated significant association between dementia and periodontal disease (mean difference: PD = 1.41; CAL = 1.40, P periodontal conditions in dementia patients, due to different study types and the high heterogeneity among them, the meta-analysis does not support the association between dementia and severity of periodontal disease. Copyright © 2018 Elsevier B.V. All rights reserved.

  14. Reporting characteristics of meta-analyses in orthodontics: methodological assessment and statistical recommendations.

    Science.gov (United States)

    Papageorgiou, Spyridon N; Papadopoulos, Moschos A; Athanasiou, Athanasios E

    2014-02-01

    Ideally meta-analyses (MAs) should consolidate the characteristics of orthodontic research in order to produce an evidence-based answer. However severe flaws are frequently observed in most of them. The aim of this study was to evaluate the statistical methods, the methodology, and the quality characteristics of orthodontic MAs and to assess their reporting quality during the last years. Electronic databases were searched for MAs (with or without a proper systematic review) in the field of orthodontics, indexed up to 2011. The AMSTAR tool was used for quality assessment of the included articles. Data were analyzed with Student's t-test, one-way ANOVA, and generalized linear modelling. Risk ratios with 95% confidence intervals were calculated to represent changes during the years in reporting of key items associated with quality. A total of 80 MAs with 1086 primary studies were included in this evaluation. Using the AMSTAR tool, 25 (27.3%) of the MAs were found to be of low quality, 37 (46.3%) of medium quality, and 18 (22.5%) of high quality. Specific characteristics like explicit protocol definition, extensive searches, and quality assessment of included trials were associated with a higher AMSTAR score. Model selection and dealing with heterogeneity or publication bias were often problematic in the identified reviews. The number of published orthodontic MAs is constantly increasing, while their overall quality is considered to range from low to medium. Although the number of MAs of medium and high level seems lately to rise, several other aspects need improvement to increase their overall quality.

  15. A literature review and meta-analyses of cannabis use and suicidality.

    Science.gov (United States)

    Borges, Guilherme; Bagge, Courtney L; Orozco, Ricardo

    2016-05-01

    We lack a review of the epidemiological literature on cannabis use (acute use and chronic-usual quantity/frequency and heavy use) and suicidality (suicide death, suicide ideation, suicide attempt). The English language literature on Medline, PsychInfo, Google Scholar, and public-use databases was searched for original articles, critical review reports, and public use data on cannabis use and suicide for the period ranging from 1990-2015 (February). Odds ratios (OR) from random effects in meta-analyses for any cannabis use and heavy cannabis use were calculated. The acute cannabis-suicidality literature mostly includes descriptive toxicology reports. In terms of death by suicide, the average positive cannabis rate was 9.50% for studies sampling from all suicides, with higher cannabis detection rates amongst suicide decedents by non-overdose methods. We found only 4 studies providing estimates for any chronic cannabis use and death by suicide (OR=2.56 (1.25-5.27)). After deleting duplicates we found 6 studies on any cannabis use and suicide ideation (OR=1.43 (1.13-1.83)), 5 studies on heavy cannabis use and suicide ideation (OR=2.53 (1.00-6.39)), 6 studies on any cannabis use and suicide attempt (OR=2.23 (1.24-4.00)) and 6 studies on heavy cannabis use and suicide attempt (OR=3.20 (1.72-5.94)). We currently lack evidence that acute cannabis use increases imminent risk for suicidality. The evidence tends to support that chronic cannabis use can predict suicidality, but the lack of homogeneity in the measurement of cannabis exposure and, in some instances, the lack of systematic control for known risk factors tempered this finding. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. "Meta-analyses and P-curves support robust cycle shifts in women's mate preferences: Reply to Wood and Carden (2014) and Harris, Pashler, and Mickes (2014)": Correction to Gildersleeve, Haselton, and Fales (2014).

    Science.gov (United States)

    2017-11-01

    Reports an error in "Meta-analyses and p -curves support robust cycle shifts in women's mate preferences: Reply to Wood and Carden (2014) and Harris, Pashler, and Mickes (2014)" by Kelly Gildersleeve, Martie G. Haselton and Melissa R. Fales ( Psychological Bulletin , 2014[Sep], Vol 140[5], 1272-1280). In the article, all p -curve analyses examining the Context Moderation Hypothesis Prediction mistakenly included the p-value from Little, Jones, Burt, & Perrett (2007) Study 2 for the simple effect of fertility on attraction to facial symmetry in a short-term relationship context ( p < .001). The analyses should have instead included the p -value for the fertility X relationship context interaction ( p = .011). In addition, the p -curve analyses examining exact two-tailed p -values for the Cycle Shift Prediction should have included an additional p -value from Provost et al. (2008) Study 1 for the main effect of fertility on attraction to gait masculinity. The reported p -value for this effect was .05, making it ineligible for inclusion in p -curves of reported p-values. However, the exact recalculated two-tailed p -value was .049, making it eligible for inclusion in p -curves of exact p -values. The corrected p -curve of exact two-tailed p -values evaluating the Cycle Shift Prediction and Context Moderation Prediction (displayed in Figure 2) now includes a total of 15 p -values ( N = 1442) is no longer significantly right skewed χ²(30) = 41.25, p = .08. The corrected p -curve of exact two-tailed p -values evaluating the Cycle Shift Prediction, Context Moderation Prediction, and Partner Qualities Moderation Prediction (displayed in Figure 3) now includes a total of 21 p -values ( N = 1707) and continues to be significantly right skewed Χ²(42) = 69.83, p = .004. As part of this correction, the online supplemental materials have been updated. (The following abstract of the original article appeared in record 2014-35938-003.) Two meta-analyses evaluated shifts across

  17. Vitamin D and Depression: A Systematic Review and Meta-Analysis Comparing Studies with and without Biological Flaws

    OpenAIRE

    Simon Spedding

    2014-01-01

    Efficacy of Vitamin D supplements in depression is controversial, awaiting further literature analysis. Biological flaws in primary studies is a possible reason meta-analyses of Vitamin D have failed to demonstrate efficacy. This systematic review and meta-analysis of Vitamin D and depression compared studies with and without biological flaws. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was un...

  18. Anxiety Levels in Children with Autism Spectrum Disorder : A Meta-Analysis

    NARCIS (Netherlands)

    van Steensel, F.J.A.; Heeman, E.J.

    The aim of the current study was to meta-analytically examine whether anxiety levels in children with autism spectrum disorders (ASD) are elevated. A total of 83 articles were selected from a systematic literature search and were included in the meta-analyses. Results demonstrated that children with

  19. Use and misuse of temperature normalisation in meta-analyses of thermal responses of biological traits

    Directory of Open Access Journals (Sweden)

    Dimitrios - Georgios Kontopoulos

    2018-02-01

    Full Text Available There is currently unprecedented interest in quantifying variation in thermal physiology among organisms, especially in order to understand and predict the biological impacts of climate change. A key parameter in this quantification of thermal physiology is the performance or value of a rate, across individuals or species, at a common temperature (temperature normalisation. An increasingly popular model for fitting thermal performance curves to data—the Sharpe-Schoolfield equation—can yield strongly inflated estimates of temperature-normalised rate values. These deviations occur whenever a key thermodynamic assumption of the model is violated, i.e., when the enzyme governing the performance of the rate is not fully functional at the chosen reference temperature. Using data on 1,758 thermal performance curves across a wide range of species, we identify the conditions that exacerbate this inflation. We then demonstrate that these biases can compromise tests to detect metabolic cold adaptation, which requires comparison of fitness or rate performance of different species or genotypes at some fixed low temperature. Finally, we suggest alternative methods for obtaining unbiased estimates of temperature-normalised rate values for meta-analyses of thermal performance across species in climate change impact studies.

  20. Is quality and completeness of reporting of systematic reviews and meta-analyses published in high impact radiology journals associated with citation rates?

    Science.gov (United States)

    van der Pol, Christian B; McInnes, Matthew D F; Petrcich, William; Tunis, Adam S; Hanna, Ramez

    2015-01-01

    The purpose of this study is to determine whether study quality and completeness of reporting of systematic reviews (SR) and meta-analyses (MA) published in high impact factor (IF) radiology journals is associated with citation rates. All SR and MA published in English between Jan 2007-Dec 2011, in radiology journals with an IF >2.75, were identified on Ovid MEDLINE. The Assessing the Methodologic Quality of Systematic Reviews (AMSTAR) checklist for study quality, and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for study completeness, was applied to each SR & MA. Each SR & MA was then searched in Google Scholar to yield a citation rate. Spearman correlation coefficients were used to assess the relationship between AMSTAR and PRISMA results with citation rate. Multivariate analyses were performed to account for the effect of journal IF and journal 5-year IF on correlation with citation rate. Values were reported as medians with interquartile range (IQR) provided. 129 studies from 11 journals were included (50 SR and 79 MA). Median AMSTAR result was 8.0/11 (IQR: 5-9) and median PRISMA result was 23.0/27 (IQR: 21-25). The median citation rate for SR & MA was 0.73 citations/month post-publication (IQR: 0.40-1.17). There was a positive correlation between both AMSTAR and PRISMA results and SR & MA citation rate; ρ=0.323 (P=0.0002) and ρ=0.327 (P=0.0002) respectively. Positive correlation persisted for AMSTAR and PRISMA results after journal IF was partialed out; ρ=0.243 (P=0.006) and ρ=0.256 (P=0.004), and after journal 5-year IF was partialed out; ρ=0.235 (P=0.008) and ρ=0.243 (P=0.006) respectively. There is a positive correlation between the quality and the completeness of a reported SR or MA with citation rate which persists when adjusted for journal IF and journal 5-year IF.

  1. Meta-analytic structural equation modelling

    CERN Document Server

    Jak, Suzanne

    2015-01-01

    This book explains how to employ MASEM, the combination of meta-analysis (MA) and structural equation modelling (SEM). It shows how by using MASEM, a single model can be tested to explain the relationships between a set of variables in several studies. This book gives an introduction to MASEM, with a focus on the state of the art approach: the two stage approach of Cheung and Cheung & Chan. Both, the fixed and the random approach to MASEM are illustrated with two applications to real data. All steps that have to be taken to perform the analyses are discussed extensively. All data and syntax files are available online, so that readers can imitate all analyses. By using SEM for meta-analysis, this book shows how to benefit from all available information from all available studies, even if few or none of the studies report about all relationships that feature in the full model of interest.

  2. Dose-related beneficial and harmful effects of gabapentin in postoperative pain management – post hoc analyses from a systematic review with meta-analyses and trial sequential analyses

    Directory of Open Access Journals (Sweden)

    Fabritius ML

    2017-11-01

    Full Text Available Maria Louise Fabritius,1 Jørn Wetterslev,2 Ole Mathiesen,3 Jørgen B Dahl1 1Department of Anaesthesiology and Intensive Care, Bispebjerg and Frederiksberg Hospitals, Copenhagen, Denmark; 2Copenhagen Trial Unit, Centre for Clinical Intervention Research, Copenhagen University Hospital, Copenhagen, Denmark; 3Department of Anaesthesiology, Zealand University Hospital, Køge, Denmark Background: During the last 15 years, gabapentin has become an established component of postoperative pain treatment. Gabapentin has been employed in a wide range of doses, but little is known about the optimal dose, providing the best balance between benefit and harm. This systematic review with meta-analyses aimed to explore the beneficial and harmful effects of various doses of gabapentin administered to surgical patients.Materials and methods: Data in this paper were derived from an original review, and the subgroup analyses were predefined in an International Prospective Register of Systematic Reviews published protocol: PROSPERO (ID: CRD42013006538. The methods followed Cochrane guidelines. The Cochrane Library’s CENTRAL, PubMed, EMBASE, Science Citation Index Expanded, Google Scholar, and FDA database were searched for relevant trials. Randomized clinical trials comparing gabapentin versus placebo were included. Four different dose intervals were investigated: 0–350, 351–700, 701–1050, and >1050 mg. Primary co-outcomes were 24-hour morphine consumption and serious adverse events (SAEs, with emphasis put on trials with low risk of bias. Results: One hundred and twenty-two randomized clinical trials, with 8466 patients, were included. Sixteen were overall low risk of bias. No consistent increase in morphine-sparing effect was observed with increasing doses of gabapentin from the trials with low risk of bias. Analyzing all trials, the smallest and the highest dose subgroups demonstrated numerically the most prominent reduction in morphine consumption

  3. Matching Procedures in Autism Research: Evidence from Meta-Analytic Studies

    Science.gov (United States)

    Shaked, Michal; Yirmiya, Nurit

    2004-01-01

    In this paper, we summarize some of our findings from a series of three meta-analyses and discuss their implications for autism research. In the first meta-analysis, we examined studies addressing the theory of mind hypothesis in autism. This analysis revealed that theory of mind disabilities are not unique to autism, although what may be unique…

  4. Meta-analyses of genome-wide association studies identify multiple loci associated with pulmonary function

    NARCIS (Netherlands)

    D.B. Hancock (Dana); M. Eijgelsheim (Mark); J.B. Wilk (Jemma); S.A. Gharib (Sina); L.R. Loehr (Laura); K. Marciante (Kristin); N. Franceschini (Nora); Y.M.T.A. van Durme; T.H. Chen; R.G. Barr (Graham); M.B. Schabath (Matthew); D.J. Couper (David); G.G. Brusselle (Guy); B.M. Psaty (Bruce); P. Tikka-Kleemola (Päivi); J.I. Rotter (Jerome); A.G. Uitterlinden (André); A. Hofman (Albert); N.M. Punjabi (Naresh); F. Rivadeneira Ramirez (Fernando); A.C. Morrison (Alanna); P.L. Enright (Paul); K.E. North (Kari); S.R. Heckbert (Susan); T. Lumley (Thomas); B.H.Ch. Stricker (Bruno); G.T. O'Connor (George); S.J. London (Stephanie)

    2010-01-01

    textabstractSpirometric measures of lung function are heritable traits that reflect respiratory health and predict morbidity and mortality. We meta-analyzed genome-wide association studies for two clinically important lung-function measures: forced expiratory volume in the first second (FEV1) and

  5. Meta-Analysis of Explicit Memory Studies in Populations with Intellectual Disability

    Science.gov (United States)

    Lifshitz, Hefziba; Shtein, Sarit; Weiss, Izhak; Vakil, Eli

    2011-01-01

    This meta-analysis combines the effect size (ES) of 40 explicit memory experiments in populations with intellectual disability (ID). Eight meta-analyses were performed, as well as contrast tests between ES. The explicit memory of participants with ID was inferior to that of participants with typical development (TD). Relatively preserved explicit…

  6. C-reactive protein gene polymorphisms and myocardial infarction risk: a meta-analysis and meta-regression.

    Science.gov (United States)

    Zhu, Yanbin; Liu, Tongku; He, Haitao; Sun, Yuqing; Zhuo, Fengling

    2013-12-01

    C-reactive protein (CRP), the classic acute-phase protein, plays an important role in the etiology of myocardial infarction (MI). Emerging evidence has shown that the common polymorphisms in the CRP gene may influence an individual's susceptibility to MI; but individually published studies showed inconclusive results. This meta-analysis aimed to derive a more precise estimation of the associations between CRP gene polymorphisms and MI risk. A literature search of PubMed, Embase, Web of Science, and China BioMedicine (CBM) databases was conducted on articles published before June 1st, 2013. Crude odds ratio (OR) with 95% confidence interval (CI) were calculated. Nine case-control studies were included with a total of 2992 MI patients and 4711 healthy controls. The meta-analysis results indicated that CRP rs3093059 (T>C) polymorphism was associated with decreased risk of MI, especially among Asian populations. However, similar associations were not observed in CRP rs1800947 (G>C) and rs2794521 (G>A) polymorphisms (all p>0.05) among both Asian and Caucasian populations. Univariate and multivariate meta-regression analyses showed that ethnicity may be a major source of heterogeneity. No publication bias was detected in this meta-analysis. In conclusion, the current meta-analysis indicates that CRP rs3093059 (T>C) polymorphism may be associated with decreased risk of MI, especially among Asian populations.

  7. Incidence and predictors of oral feeding intolerance in acute pancreatitis: A systematic review, meta-analysis, and meta-regression.

    Science.gov (United States)

    Bevan, Melody G; Asrani, Varsha M; Bharmal, Sakina; Wu, Landy M; Windsor, John A; Petrov, Maxim S

    2017-06-01

    Tolerance of oral food is an important criterion for hospital discharge in patients with acute pancreatitis. Patients who develop oral feeding intolerance have prolonged hospitalisation, use additional healthcare resources, and have impaired quality of life. This study aimed to quantify the incidence of oral feeding intolerance, the effect of confounders, and determine the best predictors of oral feeding intolerance. Clinical studies indexed in three electronic databases (EMBASE, MEDLINE, and the Cochrane Central Register of Controlled Trials) were reviewed. Incidence and predictor data were meta-analysed and possible confounders were investigated by meta-regression analysis. A total of 22 studies with 2024 patients met the inclusion criteria, 17 of which (with 1550 patients) were suitable for meta-analysis. The incidence of oral feeding intolerance was 16.3%, and was not affected by WHO region, age, sex, or aetiology of acute pancreatitis. Nine of the 22 studies investigated a total of 62 different predictors of oral feeding intolerance. Serum lipase level prior to refeeding, pleural effusions, (peri)pancreatic collections, Ranson score, and Balthazar score were found to be statistically significant in meta-analyses. Oral feeding intolerance affects approximately 1 in 6 patients with acute pancreatitis. Serum lipase levels of more than 2.5 times the upper limit of normal prior to refeeding is a potentially useful threshold to identify patients at high risk of developing oral feeding intolerance. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

  8. Stillbirth With Group B Streptococcus Disease Worldwide: Systematic Review and Meta-analyses.

    Science.gov (United States)

    Seale, Anna C; Blencowe, Hannah; Bianchi-Jassir, Fiorella; Embleton, Nicholas; Bassat, Quique; Ordi, Jaume; Menéndez, Clara; Cutland, Clare; Briner, Carmen; Berkley, James A; Lawn, Joy E; Baker, Carol J; Bartlett, Linda; Gravett, Michael G; Heath, Paul T; Ip, Margaret; Le Doare, Kirsty; Rubens, Craig E; Saha, Samir K; Schrag, Stephanie; Meulen, Ajoke Sobanjo-Ter; Vekemans, Johan; Madhi, Shabir A

    2017-11-06

    There are an estimated 2.6 million stillbirths each year, many of which are due to infections, especially in low- and middle-income contexts. This paper, the eighth in a series on the burden of group B streptococcal (GBS) disease, aims to estimate the percentage of stillbirths associated with GBS disease. We conducted systematic literature reviews (PubMed/Medline, Embase, Literatura Latino-Americana e do Caribe em Ciências da Saúde, World Health Organization Library Information System, and Scopus) and sought unpublished data from investigator groups. Studies were included if they reported original data on stillbirths (predominantly ≥28 weeks' gestation or ≥1000 g, with GBS isolated from a sterile site) as a percentage of total stillbirths. We did meta-analyses to derive pooled estimates of the percentage of GBS-associated stillbirths, regionally and worldwide for recent datasets. We included 14 studies from any period, 5 with recent data (after 2000). There were no data from Asia. We estimated that 1% (95% confidence interval [CI], 0-2%) of all stillbirths in developed countries and 4% (95% CI, 2%-6%) in Africa were associated with GBS. GBS is likely an important cause of stillbirth, especially in Africa. However, data are limited in terms of geographic spread, with no data from Asia, and cases worldwide are probably underestimated due to incomplete case ascertainment. More data, using standardized, systematic methods, are critical, particularly from low- and middle-income contexts where the highest burden of stillbirths occurs. These data are essential to inform interventions, such as maternal GBS vaccination. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  9. Meta-analyzing dependent correlations: an SPSS macro and an R script.

    Science.gov (United States)

    Cheung, Shu Fai; Chan, Darius K-S

    2014-06-01

    The presence of dependent correlation is a common problem in meta-analysis. Cheung and Chan (2004, 2008) have shown that samplewise-adjusted procedures perform better than the more commonly adopted simple within-sample mean procedures. However, samplewise-adjusted procedures have rarely been applied in meta-analytic reviews, probably due to the lack of suitable ready-to-use programs. In this article, we compare the samplewise-adjusted procedures with existing procedures to handle dependent effect sizes, and present the samplewise-adjusted procedures in a way that will make them more accessible to researchers conducting meta-analysis. We also introduce two tools, an SPSS macro and an R script, that researchers can apply to their meta-analyses; these tools are compatible with existing meta-analysis software packages.

  10. Systematic Reviews and Meta-analyses for Cardiology Fellows.

    Science.gov (United States)

    Fares, Munes; Alahdab, Fares; Alsaied, Tarek

    2016-07-01

    Participating in a scholarly activity is one of the training requirements for cardiology fellows. However, it can be very challenging to complete a research project during such a busy period of clinical training. To help the cardiology fellows in choosing and starting off a research project, a light has been shed on the process of conducting a systematic review, and the importance of this research activity, as well as its limitations. © 2016 Wiley Periodicals, Inc.

  11. Acupuncture-Related Techniques for Psoriasis: A Systematic Review with Pairwise and Network Meta-Analyses of Randomized Controlled Trials.

    Science.gov (United States)

    Yeh, Mei-Ling; Ko, Shu-Hua; Wang, Mei-Hua; Chi, Ching-Chi; Chung, Yu-Chu

    2017-12-01

    There has be a large body of evidence on the pharmacological treatments for psoriasis, but whether nonpharmacological interventions are effective in managing psoriasis remains largely unclear. This systematic review conducted pairwise and network meta-analyses to determine the effects of acupuncture-related techniques on acupoint stimulation for the treatment of psoriasis and to determine the order of effectiveness of these remedies. This study searched the following databases from inception to March 15, 2016: Medline, PubMed, Cochrane Central Register of Controlled Trials, EBSCO (including Academic Search Premier, American Doctoral Dissertations, and CINAHL), Airiti Library, and China National Knowledge Infrastructure. Randomized controlled trials (RCTs) on the effects of acupuncture-related techniques on acupoint stimulation as intervention for psoriasis were independently reviewed by two researchers. A total of 13 RCTs with 1,060 participants were included. The methodological quality of included studies was not rigorous. Acupoint stimulation, compared with nonacupoint stimulation, had a significant treatment for psoriasis. However, the most common adverse events were thirst and dry mouth. Subgroup analysis was further done to confirm that the short-term treatment effect was superior to that of the long-term effect in treating psoriasis. Network meta-analysis identified acupressure or acupoint catgut embedding, compared with medication, and had a significant effect for improving psoriasis. It was noted that acupressure was the most effective treatment. Acupuncture-related techniques could be considered as an alternative or adjuvant therapy for psoriasis in short term, especially of acupressure and acupoint catgut embedding. This study recommends further well-designed, methodologically rigorous, and more head-to-head randomized trials to explore the effects of acupuncture-related techniques for treating psoriasis.

  12. Psychosocial versus physiological stress – meta-analyses on deactivations and activations of the neural correlates of stress reactions

    Science.gov (United States)

    Kogler, Lydia; Mueller, Veronika I.; Chang, Amy; Eickhoff, Simon B.; Fox, Peter T.; Gur, Ruben C.; Derntl, Birgit

    2015-01-01

    Stress is present in everyday life in various forms and situations. Two stressors frequently investigated are physiological and psychosocial stress. Besides similar subjective and hormonal responses, it has been suggested that they also share common neural substrates. The current study used activation-likelihood-estimation meta-analysis to test this assumption by integrating results of previous neuroimaging studies on stress processing. Reported results are cluster-level FWE corrected. The inferior frontal gyrus (IFG) and the anterior insula (AI) were the only regions that demonstrated overlapping activation for both stressors. Analysis of physiological stress showed consistent activation of cognitive and affective components of pain processing such as the insula, striatum, or the middle cingulate cortex. Contrarily, analysis across psychosocial stress revealed consistent activation of the right superior temporal gyrus and deactivation of the striatum. Notably, parts of the striatum appeared to be functionally specified: the dorsal striatum was activated in physiological stress, whereas the ventral striatum was deactivated in psychosocial stress. Additional functional connectivity and decoding analyses further characterized this functional heterogeneity and revealed higher associations of the dorsal striatum with motor regions and of the ventral striatum with reward processing. Based on our meta-analytic approach, activation of the IFG and the AI seems to indicate a global neural stress reaction. While physiological stress activates a motoric fight-or-flight reaction, during psychosocial stress attention is shifted towards emotion regulation and goal-directed behavior, and reward processing is reduced. Our results show the significance of differentiating physiological and psychosocial stress in neural engagement. Furthermore, the assessment of deactivations in addition to activations in stress research is highly recommended. PMID:26123376

  13. Effect of Risk of Bias on the Effect Size of Meta-Analytic Estimates in Randomized Controlled Trials in Periodontology and Implant Dentistry

    Science.gov (United States)

    Faggion, Clovis Mariano; Wu, Yun-Chun; Scheidgen, Moritz; Tu, Yu-Kang

    2015-01-01

    Background Risk of bias (ROB) may threaten the internal validity of a clinical trial by distorting the magnitude of treatment effect estimates, although some conflicting information on this assumption exists. Objective The objective of this study was evaluate the effect of ROB on the magnitude of treatment effect estimates in randomized controlled trials (RCTs) in periodontology and implant dentistry. Methods A search for Cochrane systematic reviews (SRs), including meta-analyses of RCTs published in periodontology and implant dentistry fields, was performed in the Cochrane Library in September 2014. Random-effect meta-analyses were performed by grouping RCTs with different levels of ROBs in three domains (sequence generation, allocation concealment, and blinding of outcome assessment). To increase power and precision, only SRs with meta-analyses including at least 10 RCTs were included. Meta-regression was performed to investigate the association between ROB characteristics and the magnitudes of intervention effects in the meta-analyses. Results Of the 24 initially screened SRs, 21 SRs were excluded because they did not include at least 10 RCTs in the meta-analyses. Three SRs (two from periodontology field) generated information for conducting 27 meta-analyses. Meta-regression did not reveal significant differences in the relationship of the ROB level with the size of treatment effect estimates, although a trend for inflated estimates was observed in domains with unclear ROBs. Conclusion In this sample of RCTs, high and (mainly) unclear risks of selection and detection biases did not seem to influence the size of treatment effect estimates, although several confounders might have influenced the strength of the association. PMID:26422698

  14. On the Multilevel Nature of Meta-Analysis: A Tutorial, Comparison of Software Programs, and Discussion of Analytic Choices.

    Science.gov (United States)

    Pastor, Dena A; Lazowski, Rory A

    2018-01-01

    The term "multilevel meta-analysis" is encountered not only in applied research studies, but in multilevel resources comparing traditional meta-analysis to multilevel meta-analysis. In this tutorial, we argue that the term "multilevel meta-analysis" is redundant since all meta-analysis can be formulated as a special kind of multilevel model. To clarify the multilevel nature of meta-analysis the four standard meta-analytic models are presented using multilevel equations and fit to an example data set using four software programs: two specific to meta-analysis (metafor in R and SPSS macros) and two specific to multilevel modeling (PROC MIXED in SAS and HLM). The same parameter estimates are obtained across programs underscoring that all meta-analyses are multilevel in nature. Despite the equivalent results, not all software programs are alike and differences are noted in the output provided and estimators available. This tutorial also recasts distinctions made in the literature between traditional and multilevel meta-analysis as differences between meta-analytic choices, not between meta-analytic models, and provides guidance to inform choices in estimators, significance tests, moderator analyses, and modeling sequence. The extent to which the software programs allow flexibility with respect to these decisions is noted, with metafor emerging as the most favorable program reviewed.

  15. The influence of emotional cues on prospective memory: a systematic review with meta-analyses.

    Science.gov (United States)

    Hostler, Thomas J; Wood, Chantelle; Armitage, Christopher J

    2018-01-10

    Remembering to perform a behaviour in the future, prospective memory, is essential to ensuring that people fulfil their intentions. Prospective memory involves committing to memory a cue to action (encoding), and later recognising and acting upon the cue in the environment (retrieval). Prospective memory performance is believed to be influenced by the emotionality of the cues, however the literature is fragmented and inconsistent. We conducted a systematic search to synthesise research on the influence of emotion on prospective memory. Sixty-seven effect sizes were extracted from 17 articles and hypothesised effects tested using three meta-analyses. Overall, prospective memory was enhanced when positively-valenced rather than neutral cues were presented (d = 0.32). In contrast, negatively-valenced cues did not enhance prospective memory overall (d = 0.07), but this effect was moderated by the timing of the emotional manipulation. Prospective memory performance was improved when negatively-valenced cues were presented during both encoding and retrieval (d = 0.40), but undermined when presented only during encoding (d = -0.25). Moderating effects were also found for cue-focality and whether studies controlled for the arousal level of the cues. The principal finding is that positively-valenced cues improve prospective memory performance and that timing of the manipulation can moderate emotional effects on prospective memory. We offer a new agenda for future empirical work and theorising in this area.

  16. ETICS meta-data software editing - from check out to commit operations

    International Nuclear Information System (INIS)

    Begin, M-E; Sancho, G D-A; Ronco, S D; Gentilini, M; Ronchieri, E; Selmi, M

    2008-01-01

    People involved in modular projects need to improve the build software process, planning the correct execution order and detecting circular dependencies. The lack of suitable tools may cause delays in the development, deployment and maintenance of the software. Experience in such projects has shown that the use of version control and build systems is not able to support the development of the software efficiently, due to a large number of errors each of which causes the breaking of the build process. Common causes of errors are for example the adoption of new libraries, libraries incompatibility, the extension of the current project in order to support new software modules. In this paper, we describe a possible solution implemented in ETICS, an integrated infrastructure for the automated configuration, build and test of Grid and distributed software. ETICS has defined meta-data software abstractions, from which it is possible to download, build and test software projects, setting for instance dependencies, environment variables and properties. Furthermore, the meta-data information is managed by ETICS reflecting the version control system philosophy, because of the existence of a meta-data repository and the handling of a list of operations, such as check out and commit. All the information related to a specific software are stored in the repository only when they are considered to be correct. By means of this solution, we introduce a sort of flexibility inside the ETICS system, allowing users to work accordingly to their needs. Moreover, by introducing this functionality, ETICS will be a version control system like for the management of the meta-data

  17. Investigation of continuous effect modifiers in a meta-analysis on higher versus lower PEEP in patients requiring mechanical ventilation--protocol of the ICEM study.

    Science.gov (United States)

    Kasenda, Benjamin; Sauerbrei, Willi; Royston, Patrick; Briel, Matthias

    2014-05-20

    Categorizing an inherently continuous predictor in prognostic analyses raises several critical methodological issues: dependence of the statistical significance on the number and position of the chosen cut-point(s), loss of statistical power, and faulty interpretation of the results if a non-linear association is incorrectly assumed to be linear. This also applies to a therapeutic context where investigators of randomized clinical trials (RCTs) are interested in interactions between treatment assignment and one or more continuous predictors. Our goal is to apply the multivariable fractional polynomial interaction (MFPI) approach to investigate interactions between continuous patient baseline variables and the allocated treatment in an individual patient data meta-analysis of three RCTs (N = 2,299) from the intensive care field. For each study, MFPI will provide a continuous treatment effect function. Functions from each of the three studies will be averaged by a novel meta-analysis approach for functions. We will plot treatment effect functions separately for each study and also the averaged function. The averaged function with a related confidence interval will provide a suitable basis to assess whether a continuous patient characteristic modifies the treatment comparison and may be relevant for clinical decision-making. The compared interventions will be a higher or lower positive end-expiratory pressure (PEEP) ventilation strategy in patients requiring mechanical ventilation. The continuous baseline variables body mass index, PaO2/FiO2, respiratory compliance, and oxygenation index will be the investigated potential effect modifiers. Clinical outcomes for this analysis will be in-hospital mortality, time to death, time to unassisted breathing, and pneumothorax. This project will be the first meta-analysis to combine continuous treatment effect functions derived by the MFPI procedure separately in each of several RCTs. Such an approach requires individual

  18. Meta framing and polyphonic structures

    DEFF Research Database (Denmark)

    Pedersen, Karsten

    2017-01-01

    in various ways in BT’s 2012 coverage of a doping case involving Riis. In this article I investigate the way in which BT meta frames itself and its own actions in order to show and underline the seriousness with which BT treats sports journalism. The study is part of a recurring Danish project harvesting...

  19. Introducing Meta-Partition, a Useful Methodology to Explore Factors That Influence Ecological Effect Sizes.

    Directory of Open Access Journals (Sweden)

    Zaida Ortega

    Full Text Available The study of the heterogeneity of effect sizes is a key aspect of ecological meta-analyses. Here we propose a meta-analytic methodology to study the influence of moderators in effect sizes by splitting heterogeneity: meta-partition. To introduce this methodology, we performed a meta-partition of published data about the traits that influence species sensitivity to habitat loss, that have been previously analyzed through meta-regression. Thus, here we aim to introduce meta-partition and to make an initial comparison with meta-regression. Meta-partition algorithm consists of three steps. Step 1 is to study the heterogeneity of effect sizes under the assumption of fixed effect model. If heterogeneity is found, we perform step 2, that is, to partition the heterogeneity by the moderator that minimizes heterogeneity within a subset while maximizing heterogeneity between subsets. Then, if effect sizes of the subset are still heterogeneous, we repeat step 1 and 2 until we reach final subsets. Finally, step 3 is to integrate effect sizes of final subsets, with fixed effect model if there is homogeneity, and with random effects model if there is heterogeneity. Results show that meta-partition is valuable to assess the importance of moderators in explaining heterogeneity of effect sizes, as well as to assess the directions of these relations and to detect possible interactions between moderators. With meta-partition we have been able to evaluate the importance of moderators in a more objective way than with meta-regression, and to visualize the complex relations that may exist between them. As ecological issues are often influenced by several factors interacting in complex ways, ranking the importance of possible moderators and detecting possible interactions would make meta-partition a useful exploration tool for ecological meta-analyses.

  20. MCPerm: a Monte Carlo permutation method for accurately correcting the multiple testing in a meta-analysis of genetic association studies.

    Directory of Open Access Journals (Sweden)

    Yongshuai Jiang

    Full Text Available Traditional permutation (TradPerm tests are usually considered the gold standard for multiple testing corrections. However, they can be difficult to complete for the meta-analyses of genetic association studies based on multiple single nucleotide polymorphism loci as they depend on individual-level genotype and phenotype data to perform random shuffles, which are not easy to obtain. Most meta-analyses have therefore been performed using summary statistics from previously published studies. To carry out a permutation using only genotype counts without changing the size of the TradPerm P-value, we developed a Monte Carlo permutation (MCPerm method. First, for each study included in the meta-analysis, we used a two-step hypergeometric distribution to generate a random number of genotypes in cases and controls. We then carried out a meta-analysis using these random genotype data. Finally, we obtained the corrected permutation P-value of the meta-analysis by repeating the entire process N times. We used five real datasets and five simulation datasets to evaluate the MCPerm method and our results showed the following: (1 MCPerm requires only the summary statistics of the genotype, without the need for individual-level data; (2 Genotype counts generated by our two-step hypergeometric distributions had the same distributions as genotype counts generated by shuffling; (3 MCPerm had almost exactly the same permutation P-values as TradPerm (r = 0.999; P<2.2e-16; (4 The calculation speed of MCPerm is much faster than that of TradPerm. In summary, MCPerm appears to be a viable alternative to TradPerm, and we have developed it as a freely available R package at CRAN: http://cran.r-project.org/web/packages/MCPerm/index.html.

  1. Exercise training on skill-related physical fitness in adolescents with intellectual disability: A systematic review and meta-analysis.

    Science.gov (United States)

    Jeng, Shiau-Chian; Chang, Chia-Wei; Liu, Wen-Yu; Hou, Yu-Jen; Lin, Yang-Hua

    2017-04-01

    Skill-related fitness (SRF) is a component of physical fitness related to sports or occupational performance. Adolescents with intellectual disability (ID) can take advantage of SRF for enhancing work performance and enjoying participation with peers in leisure activities. However, few studies have examined the benefits of exercise on SRF in adolescents with ID. This study synthesized the results from the reviewed studies and determined whether exercise training improves SRF in adolescents with ID. We searched ten electronic databases and used the Physiotherapy Evidence Database (PEDro) scale to assess the methodological quality of included studies. This study pooled quantitative data where possible in statistical meta-analyses and expressed the effect sizes (ESs) as Cohen's d and converted it to Hedges's g. Eighteen studies met inclusion criteria for systematic review, of which 14 for further meta-analyses. Nine meta-analyses were conducted in this study. The results supported positive exercise training effects on agility, power, RT, and speed, but not balance (Hedges's g range -1.465-0.760) in adolescents with ID. We found only a limited number of studies exhibiting high quality evidence and were being included in the meta-analyses. Therefore, the results of our systematic review and meta-analyses should be interpreted with caution. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. MetaBAT: Metagenome Binning based on Abundance and Tetranucleotide frequence

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dongwan; Froula, Jeff; Egan, Rob; Wang, Zhong

    2014-03-21

    Grouping large fragments assembled from shotgun metagenomic sequences to deconvolute complex microbial communities, or metagenome binning, enables the study of individual organisms and their interactions. Here we developed automated metagenome binning software, called MetaBAT, which integrates empirical probabilistic distances of genome abundance and tetranucleotide frequency. On synthetic datasets MetaBAT on average achieves 98percent precision and 90percent recall at the strain level with 281 near complete unique genomes. Applying MetaBAT to a human gut microbiome data set we recovered 176 genome bins with 92percent precision and 80percent recall. Further analyses suggest MetaBAT is able to recover genome fragments missed in reference genomes up to 19percent, while 53 genome bins are novel. In summary, we believe MetaBAT is a powerful tool to facilitate comprehensive understanding of complex microbial communities.

  3. Fruits, vegetables, and bladder cancer risk: a systematic review and meta-analysis.

    Science.gov (United States)

    Vieira, Ana R; Vingeliene, Snieguole; Chan, Doris S M; Aune, Dagfinn; Abar, Leila; Navarro Rosenblatt, Deborah; Greenwood, Darren C; Norat, Teresa

    2015-01-01

    Smoking is estimated to cause about half of all bladder cancer cases. Case-control studies have provided evidence of an inverse association between fruit and vegetable intake and bladder cancer risk. As part of the World Cancer Research/American Institute for Cancer Research Continuous Update Project, we conducted a systematic review and meta-analysis of prospective studies to assess the dose-response relationship between fruit and vegetables and incidence and mortality of bladder cancer. We searched PubMed up to December 2013 for relevant prospective studies. We conducted highest compared with lowest meta-analyses and dose-response meta-analyses using random effects models to estimate summary relative risks (RRs) and 95% confidence intervals (CIs), and used restricted cubic splines to examine possible nonlinear associations. Fifteen prospective studies were included in the review. The summary RR for an increase of 1 serving/day (80 g) were 0.97 (95% CI: 0.95-0.99) I(2)  = 0%, eight studies for fruits and vegetables, 0.97 (95% CI: 0.94-1.00, I(2)  = 10%, 10 studies) for vegetables and 0.98 (95% CI: 0.96-1.00, I(2)  = 0%, 12 studies) for fruits. Results were similar in men and women and in current, former and nonsmokers. Amongst fruits and vegetables subgroups, for citrus fruits the summary RR for the highest compared with the lowest intake was 0.87 (95% CI: 0.76-0.99, I(2)  = 0%, eight studies) and for cruciferous vegetables there was evidence of a nonlinear relationship (P = 0.001). The current evidence from cohort studies is not consistent with a role for fruits and vegetables in preventing bladder cancer. © 2014 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  4. The Consequences of Perceived Discrimination for Psychological Well-Being : A Meta-Analytic Review

    NARCIS (Netherlands)

    Schmitt, Michael T.; Branscombe, Nyla R.; Postmes, Tom; Garcia, Amber

    In 2 meta-analyses, we examined the relationship between perceived discrimination and psychological well-being and tested a number of moderators of that relationship. In Meta-Analysis 1 (328 independent effect sizes, N = 144,246), we examined correlational data measuring both perceived

  5. A methodological systematic review of what's wrong with meta-ethnography reporting.

    Science.gov (United States)

    France, Emma F; Ring, Nicola; Thomas, Rebecca; Noyes, Jane; Maxwell, Margaret; Jepson, Ruth

    2014-11-19

    Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality of meta-ethnography reporting, particularly the analysis and synthesis processes. Our aim was to investigate the application and reporting of methods in recent meta-ethnography journal papers, focusing on the analysis and synthesis process and output. Methodological systematic review of health-related meta-ethnography journal papers published from 2012-2013. We searched six electronic databases, Google Scholar and Zetoc for papers using key terms including 'meta-ethnography.' Two authors independently screened papers by title and abstract with 100% agreement. We identified 32 relevant papers. Three authors independently extracted data and all authors analysed the application and reporting of methods using content analysis. Meta-ethnography was applied in diverse ways, sometimes inappropriately. In 13% of papers the approach did not suit the research aim. In 66% of papers reviewers did not follow the principles of meta-ethnography. The analytical and synthesis processes were poorly reported overall. In only 31% of papers reviewers clearly described how they analysed conceptual data from primary studies (phase 5, 'translation' of studies) and in only one paper (3%) reviewers explicitly described how they conducted the analytic synthesis process (phase 6). In 38% of papers we could not ascertain if reviewers had achieved any new interpretation of primary studies. In over 30% of papers seminal methodological texts which could have informed methods were not cited. We believe this is the first in-depth methodological systematic review of meta-ethnography conduct and reporting. Meta-ethnography is an evolving approach. Current reporting of methods, analysis and

  6. Network meta-analyses could be improved by searching more sources and by involving a librarian.

    Science.gov (United States)

    Li, Lun; Tian, Jinhui; Tian, Hongliang; Moher, David; Liang, Fuxiang; Jiang, Tongxiao; Yao, Liang; Yang, Kehu

    2014-09-01

    Network meta-analyses (NMAs) aim to rank the benefits (or harms) of interventions, based on all available randomized controlled trials. Thus, the identification of relevant data is critical. We assessed the conduct of the literature searches in NMAs. Published NMAs were retrieved by searching electronic bibliographic databases and other sources. Two independent reviewers selected studies and five trained reviewers abstracted data regarding literature searches, in duplicate. Search method details were examined using descriptive statistics. Two hundred forty-nine NMAs were included. Eight used previous systematic reviews to identify primary studies without further searching, and five did not report any literature searches. In the 236 studies that used electronic databases to identify primary studies, the median number of databases was 3 (interquartile range: 3-5). MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials were the most commonly used databases. The most common supplemental search methods included reference lists of included studies (48%), reference lists of previous systematic reviews (40%), and clinical trial registries (32%). None of these supplemental methods was conducted in more than 50% of the NMAs. Literature searches in NMAs could be improved by searching more sources, and by involving a librarian or information specialist. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Methods for meta-analysis of multiple traits using GWAS summary statistics.

    Science.gov (United States)

    Ray, Debashree; Boehnke, Michael

    2018-03-01

    Genome-wide association studies (GWAS) for complex diseases have focused primarily on single-trait analyses for disease status and disease-related quantitative traits. For example, GWAS on risk factors for coronary artery disease analyze genetic associations of plasma lipids such as total cholesterol, LDL-cholesterol, HDL-cholesterol, and triglycerides (TGs) separately. However, traits are often correlated and a joint analysis may yield increased statistical power for association over multiple univariate analyses. Recently several multivariate methods have been proposed that require individual-level data. Here, we develop metaUSAT (where USAT is unified score-based association test), a novel unified association test of a single genetic variant with multiple traits that uses only summary statistics from existing GWAS. Although the existing methods either perform well when most correlated traits are affected by the genetic variant in the same direction or are powerful when only a few of the correlated traits are associated, metaUSAT is designed to be robust to the association structure of correlated traits. metaUSAT does not require individual-level data and can test genetic associations of categorical and/or continuous traits. One can also use metaUSAT to analyze a single trait over multiple studies, appropriately accounting for overlapping samples, if any. metaUSAT provides an approximate asymptotic P-value for association and is computationally efficient for implementation at a genome-wide level. Simulation experiments show that metaUSAT maintains proper type-I error at low error levels. It has similar and sometimes greater power to detect association across a wide array of scenarios compared to existing methods, which are usually powerful for some specific association scenarios only. When applied to plasma lipids summary data from the METSIM and the T2D-GENES studies, metaUSAT detected genome-wide significant loci beyond the ones identified by univariate analyses

  8. Systematic review and meta-analysis: tools for the information age.

    Science.gov (United States)

    Weatherall, Mark

    2017-11-01

    The amount of available biomedical information is vast and growing. Natural limitations of the way clinicians and researchers approach this treasure trove of information comprise difficulties locating the information, and once located, cognitive biases may lead to inappropriate use of the information. Systematic reviews and meta-analyses represent important tools in the information age to improve knowledge and action. Systematic reviews represent a census approach to identifying literature to avoid non-response bias. They are a necessary prelude to producing combined quantitative summaries of associations or treatment effects. Meta-analysis comprises the arithmetical techniques for producing combined summaries from individual study reports. Careful, thoughtful and rigorous use of these tools is likely to enhance knowledge and action. Use of standard guidelines, such as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, or embedding these activities within collaborative groups such as the Cochrane Collaboration, are likely to lead to more useful systematic review and meta-analysis reporting. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. Incidence of schizophrenia and other psychoses in England, 1950-2009: a systematic review and meta-analyses.

    Directory of Open Access Journals (Sweden)

    James B Kirkbride

    Full Text Available We conducted a systematic review of incidence rates in England over a sixty-year period to determine the extent to which rates varied along accepted (age, sex and less-accepted epidemiological gradients (ethnicity, migration and place of birth and upbringing, time.To determine variation in incidence of several psychotic disorders as above.Published and grey literature searches (MEDLINE, PSycINFO, EMBASE, CINAHL, ASSIA, HMIC, and identification of unpublished data through bibliographic searches and author communication.Published 1950-2009; conducted wholly or partially in England; original data on incidence of non-organic adult-onset psychosis or one or more factor(s pertaining to incidence.People, 16-64 years, with first -onset psychosis, including non-affective psychoses, schizophrenia, bipolar disorder, psychotic depression and substance-induced psychosis.Title, abstract and full-text review by two independent raters to identify suitable citations. Data were extracted to a standardized extraction form. Descriptive appraisals of variation in rates, including tables and forest plots, and where suitable, random-effects meta-analyses and meta-regressions to test specific hypotheses; rate heterogeneity was assessed by the I²-statistic.83 citations met inclusion. Pooled incidence of all psychoses (N = 9 was 31.7 per 100,000 person-years (95%CI: 24.6-40.9, 23.2 (95%CI: 18.3-29.5 for non-affective psychoses (N = 8, 15.2 (95%CI: 11.9-19.5 for schizophrenia (N = 15 and 12.4 (95%CI: 9.0-17.1 for affective psychoses (N = 7. This masked rate heterogeneity (I²: 0.54-0.97, possibly explained by socio-environmental factors; our review confirmed (via meta-regression the typical age-sex interaction in psychosis risk, including secondary peak onset in women after 45 years. Rates of most disorders were elevated in several ethnic minority groups compared with the white (British population. For example, for schizophrenia: black Caribbean (pooled

  10. Incidence of schizophrenia and other psychoses in England, 1950-2009: a systematic review and meta-analyses.

    Science.gov (United States)

    Kirkbride, James B; Errazuriz, Antonia; Croudace, Tim J; Morgan, Craig; Jackson, Daniel; Boydell, Jane; Murray, Robin M; Jones, Peter B

    2012-01-01

    We conducted a systematic review of incidence rates in England over a sixty-year period to determine the extent to which rates varied along accepted (age, sex) and less-accepted epidemiological gradients (ethnicity, migration and place of birth and upbringing, time). To determine variation in incidence of several psychotic disorders as above. Published and grey literature searches (MEDLINE, PSycINFO, EMBASE, CINAHL, ASSIA, HMIC), and identification of unpublished data through bibliographic searches and author communication. Published 1950-2009; conducted wholly or partially in England; original data on incidence of non-organic adult-onset psychosis or one or more factor(s) pertaining to incidence. People, 16-64 years, with first -onset psychosis, including non-affective psychoses, schizophrenia, bipolar disorder, psychotic depression and substance-induced psychosis. Title, abstract and full-text review by two independent raters to identify suitable citations. Data were extracted to a standardized extraction form. Descriptive appraisals of variation in rates, including tables and forest plots, and where suitable, random-effects meta-analyses and meta-regressions to test specific hypotheses; rate heterogeneity was assessed by the I²-statistic. 83 citations met inclusion. Pooled incidence of all psychoses (N = 9) was 31.7 per 100,000 person-years (95%CI: 24.6-40.9), 23.2 (95%CI: 18.3-29.5) for non-affective psychoses (N = 8), 15.2 (95%CI: 11.9-19.5) for schizophrenia (N = 15) and 12.4 (95%CI: 9.0-17.1) for affective psychoses (N = 7). This masked rate heterogeneity (I²: 0.54-0.97), possibly explained by socio-environmental factors; our review confirmed (via meta-regression) the typical age-sex interaction in psychosis risk, including secondary peak onset in women after 45 years. Rates of most disorders were elevated in several ethnic minority groups compared with the white (British) population. For example, for schizophrenia: black Caribbean (pooled

  11. Efficacy and acceptability of very low energy diets in overweight and obese people with Type 2 diabetes mellitus: a systematic review with meta-analyses.

    Science.gov (United States)

    Rehackova, L; Arnott, B; Araujo-Soares, V; Adamson, A A; Taylor, R; Sniehotta, F F

    2016-05-01

    To explore the efficacy and acceptability of very low energy diets in overweight or obese adults with Type 2 diabetes. Controlled trials and qualitative studies of individuals with Type 2 diabetes that compared very low energy diets with standard care, minimal interventions, other weight loss interventions, less intensive very low energy diet interventions and very low energy diets with additional components were eligible for inclusion. Meta-analyses of changes in weight, blood glucose levels and attrition rates were performed. Acceptability of very low energy diets was assessed by attrition rates, number and severity of side effects, and by qualitative evaluations of the interventions. Four randomized, five non-randomized controlled trials and no qualitative studies (21 references, 9 studies, 346 participants) were identified. Meta-analyses showed that very low energy diets induced greater weight losses than minimal interventions, standard care or low energy diets at 3 and 6 months. No conclusive evidence for differences in outcomes between very low energy diets and Roux-en-Y gastric bypass surgery was found. Greater differences in energy prescription between intervention and comparator arms were associated with greater differences in weight loss and fasting blood glucose levels at 3 months. Attrition rates did not differ between the very low energy diets and the comparator arms at any measurement point. Very low energy diets are effective in substantial weight loss among people with Type 2 diabetes. Levels of adherence to very low energy diets in controlled studies appear to be high, although details about behaviour support provided are usually poorly described. © 2015 Diabetes UK.

  12. A meta-analytic review of life cycle assessment and flow analyses studies of palm oil biodiesel.

    Science.gov (United States)

    Manik, Yosef; Halog, Anthony

    2013-01-01

    This work reviews and performs a meta-analysis of the recent life cycle assessment and flow analyses studies palm oil biodiesel. The best available data and information are extracted, summarized, and discussed. Most studies found palm oil biodiesel would produce positive energy balance with an energy ratio between 2.27 and 4.81, and with a net energy production of 112 GJ ha(-1) y(-1). With the exception of a few studies, most conclude that palm oil biodiesel is a net emitter of greenhouse gases (GHG). The origin of oil palm plantation (planted area) is the foremost determinant of GHG emissions and C payback time (CPBT). Converting peatland forest results in GHG emissions up to 60 tons CO(2) equivalent (eq) ha(-1) y(-1) leading to 420 years of CPBT. In contrast, converting degraded land or grassland for plantation can positively offset the system to become a net sequester of 5 tons CO(2) eq ha(-1) y(-1). Few studies have discussed cradle-to-grave environmental impacts such as acidification, eutrophication, toxicity, and biodiversity, which open opportunity for further studies. Copyright © 2012 SETAC.

  13. Gender and telomere length: Systematic review and meta-analysis☆

    Science.gov (United States)

    Gardner, Michael; Bann, David; Wiley, Laura; Cooper, Rachel; Hardy, Rebecca; Nitsch, Dorothea; Martin-Ruiz, Carmen; Shiels, Paul; Sayer, Avan Aihie; Barbieri, Michelangela; Bekaert, Sofie; Bischoff, Claus; Brooks-Wilson, Angela; Chen, Wei; Cooper, Cyrus; Christensen, Kaare; De Meyer, Tim; Deary, Ian; Der, Geoff; Roux, Ana Diez; Fitzpatrick, Annette; Hajat, Anjum; Halaschek-Wiener, Julius; Harris, Sarah; Hunt, Steven C.; Jagger, Carol; Jeon, Hyo-Sung; Kaplan, Robert; Kimura, Masayuki; Lansdorp, Peter; Li, Changyong; Maeda, Toyoki; Mangino, Massimo; Nawrot, Tim S.; Nilsson, Peter; Nordfjall, Katarina; Paolisso, Giuseppe; Ren, Fu; Riabowol, Karl; Robertson, Tony; Roos, Goran; Staessen, Jan A.; Spector, Tim; Tang, Nelson; Unryn, Brad; van der Harst, Pim; Woo, Jean; Xing, Chao; Yadegarfar, Mohammad E.; Park, Jae Yong; Young, Neal; Kuh, Diana; von Zglinicki, Thomas; Ben-Shlomo, Yoav

    2015-01-01

    Background It is widely believed that females have longer telomeres than males, although results from studies have been contradictory. Methods We carried out a systematic review and meta-analyses to test the hypothesis that in humans, females have longer telomeres than males and that this association becomes stronger with increasing age. Searches were conducted in EMBASE and MEDLINE (by November 2009) and additional datasets were obtained from study investigators. Eligible observational studies measured telomeres for both females and males of any age, had a minimum sample size of 100 and included participants not part of a diseased group. We calculated summary estimates using random-effects meta-analyses. Heterogeneity between studies was investigated using sub-group analysis and meta-regression. Results Meta-analyses from 36 cohorts (36,230 participants) showed that on average females had longer telomeres than males (standardised difference in telomere length between females and males 0.090, 95% CI 0.015, 0.166; age-adjusted). There was little evidence that these associations varied by age group (p = 1.00) or cell type (p = 0.29). However, the size of this difference did vary by measurement methods, with only Southern blot but neither real-time PCR nor Flow-FISH showing a significant difference. This difference was not associated with random measurement error. Conclusions Telomere length is longer in females than males, although this difference was not universally found in studies that did not use Southern blot methods. Further research on explanations for the methodological differences is required. PMID:24365661

  14. Methotrexate-induced toxicity pharmacogenetics: an umbrella review of systematic reviews and meta-analyses.

    Science.gov (United States)

    Campbell, Jared M; Bateman, Emma; Stephenson, Matthew D; Bowen, Joanne M; Keefe, Dorothy M; Peters, Micah D J

    2016-07-01

    Methotrexate chemotherapy is associated with various toxicities which can result in the interruption or discontinuation of treatment and a subsequently raised risk of relapse. This umbrella systematic review was conducted to synthesize the results of all existing systematic reviews that investigate the pharmacogenetics of methotrexate-induced toxicity, with the aim of developing a comprehensive reference for personalized medicine. Databases searched were PubMed, Embase, JBI Database of Systematic Reviews and Implementation Reports, DARE, and ProQuest. Papers were critically appraised by two reviewers, and data were extracted using a standardized tool. Three systematic reviews on methotrexate-induced toxicity were included in the review. Meta-analyses were reported across Asian, Caucasian, pediatric and adult patients for the MTHFR C677T and A1298C polymorphisms. Toxicity outcomes included different forms of hematologic, ectodermal and hepatic toxicities. Results varied considerably depending on the patient groups and subgroups investigated in the different systematic reviews, as well as the genetic models utilized. However, significant associations were found between the MTHFR C677T allele and; hepatic toxicity, myelosuppression, oral mucositis, gastrointestinal toxicity, and skin toxicity. Additionally, limited evidence suggests that the MTHFR A1298C polymorphism may be associated with decreased risk of skin toxicity and leukopenia. This umbrella systematic review has synthesized the best available evidence on the pharmacogenetics of methotrexate toxicity. The next step in making personalized medicine for methotrexate therapy a clinical reality is research on the effectiveness and cost-effectiveness of MTHFR genotype testing to enable the close monitoring of at-risk patients for the timely initiation of rescue therapies.

  15. What Limits the Encoding Effect of Note-Taking? A Meta-Analytic Examination

    Science.gov (United States)

    Kobayashi, K.

    2005-01-01

    Previous meta-analyses indicate that the overall encoding effect of note-taking is positive but modest. This meta-analysis of 57 note-taking versus no note-taking comparison studies explored what limits the encoding effect by examining the moderating influence of seven variables: intervention, schooling level, presentation mode and length, test…

  16. Full-sky survey searching for ultra-narrow-band artificial CW signals: analysis of the results of Project META

    Science.gov (United States)

    Lemarchand, Guillermo A.

    1996-06-01

    Project META (Megachannel ExtraTerrestrial Assay), a full-sky survey for artificial narrow-band signals, has been conducted from the Harvard/Smithsonian 26 m radiotelescope at Agassiz Station and from one of the two 30 m radiotelescopes of the Instituto Argentino de Radioastronomia (IAR). The search was performed near the 1420 MHz line of neutral hydrogen, and its second harmonic, using two 8.4 X 10(superscript 6) channel Fourier spectrometers of 0.05 Hz resolution and 400 kHz of instantaneous bandwidth. The observing frequency was corrected both for motions with respect to three astronomical inertial frames, and for the effect of Earth's rotation, which provides a characteristic changing signature for narrow-band signals of extraterrestrial origin. Among the 6 X 10(superscript 13) spectral channels searched in the northern hemisphere, Horowitz and Sagan reported 37 candidates events exceeding the average threshold of 1.7 X 10(superscript -23) W m(superscript -2), while in the southern hemisphere among 2 X 10(superscript 13) spectral channels analyzed we found 19 events exceeding the same threshold. The strongest signals that survive culling for terrestrial interference lie in or near the Galactic Plane. The first high resolution southern target search around 71 stars (-90 degrees intelligence. It is showed that these narrow-band non-repeating 'events' found by Project META can be generated by (a) radiometer noise fluctuations, (b) a population of constant galactic sources which undergo deep fading and amplification due to interstellar scintillation, consistent with ETI transmissions and (c) real, transient signals of either terrestrial or extraterrestrial origin. The Bayesian test shows that hypothesis (b) and (c) are both highly preferred to (a), but the first two are about equally likely. Using this analysis we discuss the best observing strategies to determine the real origin of these 'events'.

  17. Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

    DEFF Research Database (Denmark)

    Jackson, D.; White, I.; Kostis, J.B.

    2009-01-01

    One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an...

  18. Systematically missing confounders in individual participant data meta-analysis of observational cohort studies

    NARCIS (Netherlands)

    Jackson, D.; White, I.; Kostis, J.B.; Wilson, A.C.; Folsom, A.R.; Feskens, E.J.M.

    2009-01-01

    One difficulty in performing meta-analyses of observational cohort studies is that the availability of confounders may vary between cohorts, so that some cohorts provide fully adjusted analyses while others only provide partially adjusted analyses. Commonly, analyses of the association between an

  19. Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in mood disorders: A meta-analysis.

    Science.gov (United States)

    Mazza, Mario Gennaro; Lucchi, Sara; Tringali, Agnese Grazia Maria; Rossetti, Aurora; Botti, Eugenia Rossana; Clerici, Massimo

    2018-06-08

    The immune and inflammatory system is involved in the etiology of mood disorders. Neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR) and monocyte/lymphocyte ratio (MLR) are inexpensive and reproducible biomarkers of inflammation. This is the first meta-analysis exploring the role of NLR and PLR in mood disorder. We identified 11 studies according to our inclusion criteria from the main Electronic Databases. Meta-analyses were carried out generating pooled standardized mean differences (SMDs) between index and healthy controls (HC). Heterogeneity was estimated. Relevant sensitivity and meta-regression analyses were conducted. Subjects with bipolar disorder (BD) had higher NLR and PLR as compared with HC (respectively SMD = 0.672; p analysis evidenced an influence of bipolar phase on the overall estimate whit studies including subjects in manic and any bipolar phase showing a significantly higher NLR and PLR as compared with HC whereas the effect was not significant among studies including only euthymic bipolar subjects. Meta-regression showed that age and sex influenced the relationship between BD and NLR but not the relationship between BD and PLR. Meta-analysis was not carried out for MLR because our search identified only one study when comparing BD to HC, and only one study when comparing MDD to HC. Subjects with major depressive disorder (MDD) had higher NLR as compared with HC (SMD = 0.670; p = 0.028; I 2  = 89.931%). Heterogeneity-based sensitivity analyses and meta-regression confirmed these findings. Our meta-analysis supports the hypothesis that an inflammatory activation occurs in mood disorders and NLR and PLR may be useful to detect this activation. More researches including comparison of NLR, PLR and MLR between different bipolar phases and between BD and MDD are needed. Copyright © 2018 Elsevier Inc. All rights reserved.

  20. STRUCTURE OF RUSSIAN PUBLICATIONS IN CLINICAL IMMUNOLOGY AND ALLERGOLOGY (JOURNAL ARTICLES, CLINICAL TRIALS, META-ANALYSES AND PRACTICE GUIDELINES) IN COMPARISON WITH OTHER BRICS COUNTRIES IN 2008-2015

    OpenAIRE

    L. I. Lugacheva; M. I. Musatov

    2018-01-01

    It is obvious that any evolving scientific medical field is a dynamic system that cannot stay at the stage of accumulation of primary information, and inevitably goes to the stages of clinical trials, generalization of information in meta-analyses and completes the study by creation of practical guidelines. The purpose of this study was a quantitative analysis of publicly available data in the field of clinical immunology in Russia during 2008-2015, identifying the ratios of clinical trials, ...

  1. Early studies reported extreme findings with large variability: a meta-epidemiologic study in the field of endocrinology.

    Science.gov (United States)

    Wang, Zhen; Alahdab, Fares; Almasri, Jehad; Haydour, Qusay; Mohammed, Khaled; Abu Dabrh, Abd Moain; Prokop, Larry J; Alfarkh, Wedad; Lakis, Sumaya; Montori, Victor M; Murad, Mohammad Hassan

    2016-04-01

    To evaluate the presence of extreme findings and fluctuation in effect size in endocrinology. We systematically identified all meta-analyses published in 2014 in the field of endocrinology. Within each meta-analysis, the effect size of the primary binary outcome was compared across studies according to their order of publication. We pooled studies using the DerSimonian and Laird random-effects method. Heterogeneity was evaluated using the I(2) and tau(2). Twelve percent of the included 100 meta-analyses reported the largest effect size in the very first published study. The largest effect size occurred in the first 2 earliest studies in 31% of meta-analyses. When the effect size was the largest in the first published study, it was three times larger than the final pooled effect (ratio of rates, 3.26; 95% confidence interval: 1.80, 5.90). The largest heterogeneity measured by I(2) was observed in 18% of the included meta-analyses when combining the first 2 studies or 17% when combing the first 3 studies. In endocrinology, early studies reported extreme findings with large variability. This behavior of the evidence needs to be taken into account when used to formulate clinical policies. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Risk and Protective Factors for Intimate Partner Violence Against Women: Systematic Review and Meta-analyses of Prospective-Longitudinal Studies.

    Science.gov (United States)

    Yakubovich, Alexa R; Stöckl, Heidi; Murray, Joseph; Melendez-Torres, G J; Steinert, Janina I; Glavin, Calla E Y; Humphreys, David K

    2018-07-01

    The estimated lifetime prevalence of physical or sexual intimate partner violence (IPV) is 30% among women worldwide. Understanding risk and protective factors is essential for designing effective prevention strategies. To quantify the associations between prospective-longitudinal risk and protective factors and IPV and identify evidence gaps. We conducted systematic searches in 16 databases including MEDLINE and PsycINFO from inception to June 2016. The study protocol is registered with PROSPERO (CRD42016039213). We included published and unpublished studies available in English that prospectively analyzed any risk or protective factor(s) for self-reported IPV victimization among women and controlled for at least 1 other variable. Three reviewers were involved in study screening. One reviewer extracted estimates of association and study characteristics from each study and 2 reviewers independently checked a random subset of extractions. We assessed study quality with the Cambridge Quality Checklists. When studies investigated the same risk or protective factor using similar measures, we computed pooled odds ratios (ORs) by using random-effects meta-analyses. We summarized heterogeneity with I 2 and τ 2 . We synthesized all estimates of association, including those not meta-analyzed, by using harvest plots to illustrate evidence gaps and trends toward negative or positive associations. Of 18 608 studies identified, 60 were included and 35 meta-analyzed. Most studies were based in the United States. The strongest evidence for modifiable risk factors for IPV against women were unplanned pregnancy (OR = 1.66; 95% confidence interval [CI] = 1.20, 1.31) and having parents with less than a high-school education (OR = 1.55; 95% CI = 1.10, 2.17). Being older (OR = 0.96; 95% CI = 0.93, 0.98) or married (OR = 0.93; 95% CI = 0.87, 0.99) were protective. To our knowledge, this is the first systematic, meta-analytic review of all risk and

  3. The aquadeb project (phase i): Analysing the physiological flexibility processes by using dynamic energy budgets.

    NARCIS (Netherlands)

    Alunno-Bruscia, M.; v.d. Veer, H.; Kooijman, S.A.L.M.

    2009-01-01

    The European Research Project AquaDEB (2007-2011, http://www.ifremer.fr/aquadeb/) is joining skills and expertise of some French and Dutch research institutes and universities to analyse the physiological flexibility of aquatic organisms and to link it to ecological and evolutionary processes within

  4. Likelihood ratio meta-analysis: New motivation and approach for an old method.

    Science.gov (United States)

    Dormuth, Colin R; Filion, Kristian B; Platt, Robert W

    2016-03-01

    A 95% confidence interval (CI) in an updated meta-analysis may not have the expected 95% coverage. If a meta-analysis is simply updated with additional data, then the resulting 95% CI will be wrong because it will not have accounted for the fact that the earlier meta-analysis failed or succeeded to exclude the null. This situation can be avoided by using the likelihood ratio (LR) as a measure of evidence that does not depend on type-1 error. We show how an LR-based approach, first advanced by Goodman, can be used in a meta-analysis to pool data from separate studies to quantitatively assess where the total evidence points. The method works by estimating the log-likelihood ratio (LogLR) function from each study. Those functions are then summed to obtain a combined function, which is then used to retrieve the total effect estimate, and a corresponding 'intrinsic' confidence interval. Using as illustrations the CAPRIE trial of clopidogrel versus aspirin in the prevention of ischemic events, and our own meta-analysis of higher potency statins and the risk of acute kidney injury, we show that the LR-based method yields the same point estimate as the traditional analysis, but with an intrinsic confidence interval that is appropriately wider than the traditional 95% CI. The LR-based method can be used to conduct both fixed effect and random effects meta-analyses, it can be applied to old and new meta-analyses alike, and results can be presented in a format that is familiar to a meta-analytic audience. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Dcumento Rechazo MetaBiblioteca

    OpenAIRE

    prueba1, prueba; Informe actividades realizadas sobre OJS UPTC

    2016-01-01

    Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Rechazo MetaBiblioteca Dcumento Recha...

  6. Network meta-analysis-highly attractive but more methodological research is needed

    Directory of Open Access Journals (Sweden)

    Singh Sonal

    2011-06-01

    Full Text Available Abstract Network meta-analysis, in the context of a systematic review, is a meta-analysis in which multiple treatments (that is, three or more are being compared using both direct comparisons of interventions within randomized controlled trials and indirect comparisons across trials based on a common comparator. To ensure validity of findings from network meta-analyses, the systematic review must be designed rigorously and conducted carefully. Aspects of designing and conducting a systematic review for network meta-analysis include defining the review question, specifying eligibility criteria, searching for and selecting studies, assessing risk of bias and quality of evidence, conducting a network meta-analysis, interpreting and reporting findings. This commentary summarizes the methodologic challenges and research opportunities for network meta-analysis relevant to each aspect of the systematic review process based on discussions at a network meta-analysis methodology meeting we hosted in May 2010 at the Johns Hopkins Bloomberg School of Public Health. Since this commentary reflects the discussion at that meeting, it is not intended to provide an overview of the field.

  7. An innovative and comprehensive technique to evaluate different measures of medication adherence: The network meta-analysis.

    Science.gov (United States)

    Tonin, Fernanda S; Wiecek, Elyssa; Torres-Robles, Andrea; Pontarolo, Roberto; Benrimoj, Shalom Charlie I; Fernandez-Llimos, Fernando; Garcia-Cardenas, Victoria

    2018-05-19

    Poor medication adherence is associated with adverse health outcomes and higher costs of care. However, inconsistencies in the assessment of adherence are found in the literature. To evaluate the effect of different measures of adherence in the comparative effectiveness of complex interventions to enhance patients' adherence to prescribed medications. A systematic review with network meta-analysis was performed. Electronic searches for relevant pairwise meta-analysis including trials of interventions that aimed to improve medication adherence were performed in PubMed. Data extraction was conducted with eligible trials evaluating short-period adherence follow-up (until 3 months) using any measure of adherence: self-report, pill count, or MEMS (medication event monitoring system). To standardize the results obtained with these different measures, an overall composite measure and an objective composite measure were also calculated. Network meta-analyses for each measure of adherence were built. Rank order and surface under the cumulative ranking curve analyses (SUCRA) were performed. Ninety-one trials were included in the network meta-analyses. The five network meta-analyses demonstrated robustness and reliability. Results obtained for all measures of adherence were similar across them and to both composite measures. For both composite measures, interventions comprising economic + technical components were the best option (90% of probability in SUCRA analysis) with statistical superiority against almost all other interventions and against standard care (odds ratio with 95% credibility interval ranging from 0.09 to 0.25 [0.02, 0.98]). The use of network meta-analysis was reliable to compare different measures of adherence of complex interventions in short-periods follow-up. Analyses with longer follow-up periods are needed to confirm these results. Different measures of adherence produced similar results. The use of composite measures revealed reliable alternatives

  8. Using beta coefficients to impute missing correlations in meta-analysis research: Reasons for caution.

    Science.gov (United States)

    Roth, Philip L; Le, Huy; Oh, In-Sue; Van Iddekinge, Chad H; Bobko, Philip

    2018-06-01

    Meta-analysis has become a well-accepted method for synthesizing empirical research about a given phenomenon. Many meta-analyses focus on synthesizing correlations across primary studies, but some primary studies do not report correlations. Peterson and Brown (2005) suggested that researchers could use standardized regression weights (i.e., beta coefficients) to impute missing correlations. Indeed, their beta estimation procedures (BEPs) have been used in meta-analyses in a wide variety of fields. In this study, the authors evaluated the accuracy of BEPs in meta-analysis. We first examined how use of BEPs might affect results from a published meta-analysis. We then developed a series of Monte Carlo simulations that systematically compared the use of existing correlations (that were not missing) to data sets that incorporated BEPs (that impute missing correlations from corresponding beta coefficients). These simulations estimated ρ̄ (mean population correlation) and SDρ (true standard deviation) across a variety of meta-analytic conditions. Results from both the existing meta-analysis and the Monte Carlo simulations revealed that BEPs were associated with potentially large biases when estimating ρ̄ and even larger biases when estimating SDρ. Using only existing correlations often substantially outperformed use of BEPs and virtually never performed worse than BEPs. Overall, the authors urge a return to the standard practice of using only existing correlations in meta-analysis. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  9. Open meta-search with OpenSearch: a case study

    OpenAIRE

    O'Riordan, Adrian P.

    2007-01-01

    The goal of this project was to demonstrate the possibilities of open source search engine and aggregation technology in a Web environment by building a meta-search engine which employs free open search engines and open protocols. In contrast many meta-search engines on the Internet use proprietary search systems. The search engines employed in this case study are all based on the OpenSearch protocol. OpenSearch-compliant systems support XML technologies such as RSS and Atom for aggregation a...

  10. Meta-analysis in applied ecology.

    Science.gov (United States)

    Stewart, Gavin

    2010-02-23

    This overview examines research synthesis in applied ecology and conservation. Vote counting and pooling unweighted averages are widespread despite the superiority of syntheses based on weighted combination of effects. Such analyses allow exploration of methodological uncertainty in addition to consistency of effects across species, space and time, but exploring heterogeneity remains controversial. Meta-analyses are required to generalize in ecology, and to inform evidence-based decision-making, but the more sophisticated statistical techniques and registers of research used in other disciplines must be employed in ecology to fully realize their benefits.

  11. Evaluation of the association between acne and smoking: systematic review and meta-analysis of cross-sectional studies

    Directory of Open Access Journals (Sweden)

    Alice Mannocci

    2010-09-01

    Full Text Available MetaPlusBook-Roman; font-size: x-small;">

    Background: Acne vulgaris is one of the most common skin diseases with a multifactorial pathogenesis. Examination of the literature regarding the contribution of smoking to acne shows contradictory results. The aim of this study was to undertake a systematic review of the literature and meta-analysis about the association between acne and smoking.

    Methods: A systematic review and meta-analysis, when possible were performed. The literature review was based on Pubmed, Scopus and Google Scholar searches using the keywords “(smoking OR tobacco OR nicotine OR cigarettes AND acne”. Only cross-sectional studies were included. Meta-analyses were performed using the RevMan software version 5 for Windows. Four different meta-analyses were carried out: one evaluating the association between smoking habit and acne, one including data stratified by gender, one for studies with a quality score > 6, and one relating to acne classification.

    Results: Six studies were selected. The first meta-analysis, including all studies, showed a non significant role of smoke in the development of acne: OR 1.05 (95% CI: 0.66–1.67 with random effect estimate. The second meta-analyses, including data stratified by gender, showed a OR=0.99 (95% CI: 0.57–1.73 for males and a OR of 1.45 (95% CI: 0.08–24.64 for females, using random effect for the heterogeneity in both cases. The third meta-analysis, included studies with a quality score >6 resulted in an estimated OR= 0.69 (95% CI: 0.55–0.85: in this case it was possible to use the fixed effect estimate. The last meta-analysis, concerning the severity grading, showed a non-significant result: OR=1.09 (95% CI: 0.61–1.95 using the random effect approach.

    Conclusions: The first two meta-analyses found no signification association between smoking and

  12. Joyful and serious intentions in the work of hospital clowns: A meta-analysis based on a 7-year research project conducted in three parts

    Directory of Open Access Journals (Sweden)

    Lotta Linge

    2013-01-01

    Full Text Available The present meta-analysis focuses on a 7-year research project entitled “Hospital clowns—in encounters with ailing children” and funded by the Swedish Childhood Cancer Foundation. The aim of the meta-analysis, which is based on the project's three studies, was to attempt to achieve a deeper psychological and more nuanced understanding of the unique encounters taking place between the hospital clowns and ailing children in the study. The methodological procedures were qualitative and included 51 interviews with four informant groups: the clowns, staff, children, and their parents. The meta-analysis revealed the unique aspects of hospital clowns’ work with respect to: a a quality of care that transcends boundaries, that is, a magical safe area where demands and adjustment were temporarily set aside and where the lighter side of life took precedence; b a non-demanding quality of care, where joy could be experienced without requiring something in return, where the child's terms mattered and where the child perspective was clearly in focus; and c a defusing quality of care, which is expressed as a positive counterweight that was otherwise lacking in medical care, where the hospital clowns used different solutions that bypassed regular hospital routines by temporarily distracting and making things easier for the children, parents, and staff in various care situations. Finally, the aim of the theoretical framework, in its synthesizing form, was to promote further psychological understanding of the area of humor that exists between fantasy and reality—an intermediate or transitional area that the hospital clowns created together with the children. In this transitional area, the hospital clowns’ unique contribution can be interpreted, in psychological terms, as being available as a vicarious therapeutic clown figure in a magical world that parallels reality.

  13. Pooling, meta-analysis, and the evaluation of drug safety

    Directory of Open Access Journals (Sweden)

    Leizorovicz Alain

    2002-03-01

    Full Text Available Abstract Background The "integrated safety report" of the drug registration files submitted to health authorities usually summarizes the rates of adverse events observed for a new drug, placebo or active control drugs by pooling the safety data across the trials. Pooling consists of adding the numbers of events observed in a given treatment group across the trials and dividing the results by the total number of patients included in this group. Because it considers treatment groups rather than studies, pooling ignores validity of the comparisons and is subject to a particular kind of bias, termed "Simpson's paradox." In contrast, meta-analysis and other stratified analyses are less susceptible to bias. Methods We use a hypothetical, but not atypical, application to demonstrate that the results of a meta-analysis can differ greatly from those obtained by pooling the same data. In our hypothetical model, a new drug is compared to 1 a placebo in 4 relatively small trials in patients at high risk for a certain adverse event and 2 an active reference drug in 2 larger trials of patients at low risk for this event. Results Using meta-analysis, the relative risk of experiencing the adverse event with the new drug was 1.78 (95% confidence interval [1.02; 3.12] compared to placebo and 2.20 [0.76; 6.32] compared to active control. By pooling the data, the results were, respectively, 1.00 [0.59; 1.70] and 5.20 [2.07; 13.08]. Conclusions Because these findings could mislead health authorities and doctors, regulatory agencies should require meta-analyses or stratified analyses of safety data in drug registration files.

  14. Meta-analysis on the efficacy of foot-and-mouth disease emergency vaccination

    DEFF Research Database (Denmark)

    Hisham Beshara Halasa, Tariq; Boklund, Anette; Cox, S.

    2012-01-01

    The objectives of this study were to provide a summary quantification of the efficacy of FMD emergency vaccination based on a systematic review and a meta-analysis of available literature, and to further discuss the suitability of this review and meta-analysis to summarize and further interpret...... of clinical signs including FMD lesions and fever, while the virological protection parameter was estimated based on the outcome of laboratory tests that were used to diagnose FMD infection. A meta-analysis relative risk was calculated per protection parameter. Results of the meta-analyses were examined using...... vaccine. Fortunately, no significant bias that would alter the conclusions was encountered in the analysis. Meta-analysis showed to be a useful tool to summarize literature results from a systematic review of the efficacy of foot and mouth disease emergency vaccination....

  15. Meta-analysis: banding ligation and medical interventions for the prevention of rebleeding from oesophageal varices

    DEFF Research Database (Denmark)

    Thiele, Maja; Krag, A; Rohde, Ulrich

    2012-01-01

    In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal.......In patients with oesophageal varices, the combination of endoscopic variceal ligation (EVL) and medical therapy is recommended as standard of care for prevention of rebleeding. The results of previous meta-analyses on this topic are equivocal....

  16. The differential impact of scientific quality, bibliometric factors, and social media activity on the influence of systematic reviews and meta-analyses about psoriasis.

    Science.gov (United States)

    Ruano, Juan; Aguilar-Luque, Macarena; Gómez-Garcia, Francisco; Alcalde Mellado, Patricia; Gay-Mimbrera, Jesus; Carmona-Fernandez, Pedro J; Maestre-López, Beatriz; Sanz-Cabanillas, Juan Luís; Hernández Romero, José Luís; González-Padilla, Marcelino; Vélez García-Nieto, Antonio; Isla-Tejera, Beatriz

    2018-01-01

    Researchers are increasingly using on line social networks to promote their work. Some authors have suggested that measuring social media activity can predict the impact of a primary study (i.e., whether or not an article will be highly cited). However, the influence of variables such as scientific quality, research disclosures, and journal characteristics on systematic reviews and meta-analyses has not yet been assessed. The present study aims to describe the effect of complex interactions between bibliometric factors and social media activity on the impact of systematic reviews and meta-analyses about psoriasis (PROSPERO 2016: CRD42016053181). Methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool. Altmetrics, which consider Twitter, Facebook, and Google+ mention counts as well as Mendeley and SCOPUS readers, and corresponding article citation counts from Google Scholar were obtained for each article. Metadata and journal-related bibliometric indices were also obtained. One-hundred and sixty-four reviews with available altmetrics information were included in the final multifactorial analysis, which showed that social media and impact factor have less effect than Mendeley and SCOPUS readers on the number of cites that appear in Google Scholar. Although a journal's impact factor predicted the number of tweets (OR, 1.202; 95% CI, 1.087-1.049), the years of publication and the number of Mendeley readers predicted the number of citations in Google Scholar (OR, 1.033; 95% CI, 1.018-1.329). Finally, methodological quality was related neither with bibliometric influence nor social media activity for systematic reviews. In conclusion, there seems to be a lack of connectivity between scientific quality, social media activity, and article usage, thus predicting scientific success based on these variables may be inappropriate in the particular case of systematic reviews.

  17. The differential impact of scientific quality, bibliometric factors, and social media activity on the influence of systematic reviews and meta-analyses about psoriasis

    Science.gov (United States)

    Gómez-Garcia, Francisco; Alcalde Mellado, Patricia; Gay-Mimbrera, Jesus; Carmona-Fernandez, Pedro J.; Maestre-López, Beatriz; Sanz-Cabanillas, Juan Luís; Hernández Romero, José Luís; González-Padilla, Marcelino; Vélez García-Nieto, Antonio; Isla-Tejera, Beatriz

    2018-01-01

    Researchers are increasingly using on line social networks to promote their work. Some authors have suggested that measuring social media activity can predict the impact of a primary study (i.e., whether or not an article will be highly cited). However, the influence of variables such as scientific quality, research disclosures, and journal characteristics on systematic reviews and meta-analyses has not yet been assessed. The present study aims to describe the effect of complex interactions between bibliometric factors and social media activity on the impact of systematic reviews and meta-analyses about psoriasis (PROSPERO 2016: CRD42016053181). Methodological quality was assessed using the Assessing the Methodological Quality of Systematic Reviews (AMSTAR) tool. Altmetrics, which consider Twitter, Facebook, and Google+ mention counts as well as Mendeley and SCOPUS readers, and corresponding article citation counts from Google Scholar were obtained for each article. Metadata and journal-related bibliometric indices were also obtained. One-hundred and sixty-four reviews with available altmetrics information were included in the final multifactorial analysis, which showed that social media and impact factor have less effect than Mendeley and SCOPUS readers on the number of cites that appear in Google Scholar. Although a journal’s impact factor predicted the number of tweets (OR, 1.202; 95% CI, 1.087–1.049), the years of publication and the number of Mendeley readers predicted the number of citations in Google Scholar (OR, 1.033; 95% CI, 1.018–1.329). Finally, methodological quality was related neither with bibliometric influence nor social media activity for systematic reviews. In conclusion, there seems to be a lack of connectivity between scientific quality, social media activity, and article usage, thus predicting scientific success based on these variables may be inappropriate in the particular case of systematic reviews. PMID:29377889

  18. The CIEMAT’s forensic analyses of Fukushima accident: Contribution to the BSAF project

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, L.E.; López, C.; Fontanet, J.; Fernández, E.

    2015-07-01

    The Fukushima accident is being both a unique opportunity and a huge challenge for severe accident analysis. Through the simulation of the accidents in Units 1 through 3 with MELCOR 2.1, three scenarios have been postulated which outcomes look consistent with data. These analyses indicate that a massive core damage should have happened in Unit 1, with most core molten and located in the containment, whereas Units 2 and 3 core damage is anticipated to be much less; however, there might be differences among these “twin” units. Anyway, in all the units the amount of H2 produced is over 500 kg. This work has been carried out in the frame of the international project for the understanding of the severe accidents occurred at Fukushima, the OECD-BSAF project. (Author)

  19. Meta-analyses of the relationship between conformity to masculine norms and mental health-related outcomes.

    Science.gov (United States)

    Wong, Y Joel; Ho, Moon-Ho Ringo; Wang, Shu-Yi; Miller, I S Keino

    2017-01-01

    Despite theoretical postulations that individuals' conformity to masculine norms is differentially related to mental health-related outcomes depending on a variety of contexts, there has not been any systematic synthesis of the empirical research on this topic. Therefore, the authors of this study conducted meta-analyses of the relationships between conformity to masculine norms (as measured by the Conformity to Masculine Norms Inventory-94 and other versions of this scale) and mental health-related outcomes using 78 samples and 19,453 participants. Conformity to masculine norms was modestly and unfavorably associated with mental health as well as moderately and unfavorably related to psychological help seeking. The authors also identified several moderation effects. Conformity to masculine norms was more strongly correlated with negative social functioning than with psychological indicators of negative mental health. Conformity to the specific masculine norms of self-reliance, power over women, and playboy were unfavorably, robustly, and consistently related to mental health-related outcomes, whereas conformity to the masculine norm of primacy of work was not significantly related to any mental health-related outcome. These findings highlight the need for researchers to disaggregate the generic construct of conformity to masculine norms and to focus instead on specific dimensions of masculine norms and their differential associations with other outcomes. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Personality and team performance: a meta analysis

    NARCIS (Netherlands)

    Peeters, Miranda A.G.; van Tuijl, Harrie F.J.M.; Rutte, Christel G.; Reymen, Isabelle

    2006-01-01

    Using a meta-analytical procedure, the relationship between team composition in terms of the Big-Five personality traits (trait elevation and variability) and team performance were researched. The number of teams upon which analyses were performed ranged from 106 to 527. For the total sample,

  1. Methadone dose and neonatal abstinence syndrome-systematic review and meta-analysis.

    LENUS (Irish Health Repository)

    Cleary, Brian J

    2012-02-01

    AIM: To determine if there is a relationship between maternal methadone dose in pregnancy and the diagnosis or medical treatment of neonatal abstinence syndrome (NAS). METHODS: PubMed, EMBASE, the Cochrane Library and PsychINFO were searched for studies reporting on methadone use in pregnancy and NAS (1966-2009). The relative risk (RR) of NAS was compared for methadone doses above versus below a range of cut-off points. Summary RRs and 95% confidence intervals (CI) were estimated using random effects meta-analysis. Sensitivity analyses explored the impact of limiting meta-analyses to prospective studies or studies using an objective scoring system to diagnose NAS. RESULTS: A total of 67 studies met inclusion criteria for the systematic review; 29 were included in the meta-analysis. Any differences in the incidence of NAS in infants of women on higher compared with lower doses were statistically non-significant in analyses restricted to prospective studies or to those using an objective scoring system to diagnose NAS. CONCLUSIONS: Severity of the neonatal abstinence syndrome does not appear to differ according to whether mothers are on high- or low-dose methadone maintenance therapy.

  2. A new miniaturized negative-index meta-atom for tri-band applications

    Directory of Open Access Journals (Sweden)

    Hossain Mohammad Jakir

    2017-07-01

    Full Text Available In this paper, a miniature negative index meta-atom was designed; simulated, fabricated and measured based on parallel incidence of electromagnetic wave that can maintain a tri-band applications in microwave spectra. Compare to the other multi-band conventional metamaterial, the proposed meta-atom structure allows miniaturization factor and follows better effective medium ratio (EMR. Finite-integration technique (FIT based computer simulation technology (CST electromagnetic simulator was adopted to examine the design of the meta-atom. It exhibits tri-band response in conjunction with backward wave property over a certain frequency band in the microwave regime. Furthermore, the effective medium ratio is considerably improved compared to previously reported metamaterial. Moreover, few parametric analyses were done with the meta-atom. The size, scattering parameters and effective medium parameters of the proposed negative index miniaturized meta-atom is appropriate for tri-band applications.

  3. Vitamin D and depression: a systematic review and meta-analysis comparing studies with and without biological flaws.

    Science.gov (United States)

    Spedding, Simon

    2014-04-11

    Efficacy of Vitamin D supplements in depression is controversial, awaiting further literature analysis. Biological flaws in primary studies is a possible reason meta-analyses of Vitamin D have failed to demonstrate efficacy. This systematic review and meta-analysis of Vitamin D and depression compared studies with and without biological flaws. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The literature search was undertaken through four databases for randomized controlled trials (RCTs). Studies were critically appraised for methodological quality and biological flaws, in relation to the hypothesis and study design. Meta-analyses were performed for studies according to the presence of biological flaws. The 15 RCTs identified provide a more comprehensive evidence-base than previous systematic reviews; methodological quality of studies was generally good and methodology was diverse. A meta-analysis of all studies without flaws demonstrated a statistically significant improvement in depression with Vitamin D supplements (+0.78 CI +0.24, +1.27). Studies with biological flaws were mainly inconclusive, with the meta-analysis demonstrating a statistically significant worsening in depression by taking Vitamin D supplements (-1.1 CI -0.7, -1.5). Vitamin D supplementation (≥800 I.U. daily) was somewhat favorable in the management of depression in studies that demonstrate a change in vitamin levels, and the effect size was comparable to that of anti-depressant medication.

  4. Working memory circuit as a function of increasing age in healthy adolescence: A systematic review and meta-analyses.

    Science.gov (United States)

    Andre, Julia; Picchioni, Marco; Zhang, Ruibin; Toulopoulou, Timothea

    2016-01-01

    Working memory ability matures through puberty and early adulthood. Deficits in working memory are linked to the risk of onset of neurodevelopmental disorders such as schizophrenia, and there is a significant temporal overlap between the peak of first episode psychosis risk and working memory maturation. In order to characterize the normal working memory functional maturation process through this critical phase of cognitive development we conducted a systematic review and coordinate based meta-analyses of all the available primary functional magnetic resonance imaging studies (n = 382) that mapped WM function in healthy adolescents (10-17 years) and young adults (18-30 years). Activation Likelihood Estimation analyses across all WM tasks revealed increased activation with increasing subject age in the middle frontal gyrus (BA6) bilaterally, the left middle frontal gyrus (BA10), the left precuneus and left inferior parietal gyri (BA7; 40). Decreased activation with increasing age was found in the right superior frontal (BA8), left junction of postcentral and inferior parietal (BA3/40), and left limbic cingulate gyrus (BA31). These results suggest that brain activation during adolescence increased with age principally in higher order cortices, part of the core working memory network, while reductions were detected in more diffuse and potentially more immature neural networks. Understanding the process by which the brain and its cognitive functions mature through healthy adulthood may provide us with new clues to understanding the vulnerability to neurodevelopmental disorders.

  5. Working memory circuit as a function of increasing age in healthy adolescence: A systematic review and meta-analyses

    Directory of Open Access Journals (Sweden)

    Julia Andre

    2016-01-01

    Full Text Available Working memory ability matures through puberty and early adulthood. Deficits in working memory are linked to the risk of onset of neurodevelopmental disorders such as schizophrenia, and there is a significant temporal overlap between the peak of first episode psychosis risk and working memory maturation. In order to characterize the normal working memory functional maturation process through this critical phase of cognitive development we conducted a systematic review and coordinate based meta-analyses of all the available primary functional magnetic resonance imaging studies (n = 382 that mapped WM function in healthy adolescents (10–17 years and young adults (18–30 years. Activation Likelihood Estimation analyses across all WM tasks revealed increased activation with increasing subject age in the middle frontal gyrus (BA6 bilaterally, the left middle frontal gyrus (BA10, the left precuneus and left inferior parietal gyri (BA7; 40. Decreased activation with increasing age was found in the right superior frontal (BA8, left junction of postcentral and inferior parietal (BA3/40, and left limbic cingulate gyrus (BA31. These results suggest that brain activation during adolescence increased with age principally in higher order cortices, part of the core working memory network, while reductions were detected in more diffuse and potentially more immature neural networks. Understanding the process by which the brain and its cognitive functions mature through healthy adulthood may provide us with new clues to understanding the vulnerability to neurodevelopmental disorders.

  6. Comparison of metformin and insulin versus insulin alone for type 2 diabetes: systematic review of randomised clinical trials with meta-analyses and trial sequential analyses.

    Science.gov (United States)

    Hemmingsen, Bianca; Christensen, Louise Lundby; Wetterslev, Jørn; Vaag, Allan; Gluud, Christian; Lund, Søren S; Almdal, Thomas

    2012-04-19

    To compare the benefits and harms of metformin and insulin versus insulin alone as reported in randomised clinical trials of patients with type 2 diabetes. Systematic review of randomised clinical trials with meta-analyses and trial sequential analyses. The Cochrane Library, Medline, Embase, Science Citation Index Expanded, Latin American Caribbean Health Sciences Literature, and Cumulative Index to Nursing and Allied Health Literature until March 2011. We also searched abstracts presented at the American Diabetes Association and European Association for the Study of Diabetes Congresses, contacted relevant trial authors and pharmaceutical companies, hand searched reference lists of included trials, and searched the US Food and Drug Administration website. Two authors independently screened titles and abstracts for randomised clinical trials comparing metformin and insulin versus insulin alone (with or without placebo) in patients with type 2 diabetes, older than 18 years, and with an intervention period of at least 12 weeks. We included trials irrespective of language, publication status, predefined outcomes, antidiabetic interventions used before randomisation, and reported outcomes. We included 26 randomised trials with 2286 participants, of which 23 trials with 2117 participants could provide data. All trials had high risk of bias. Data were sparse for outcomes relevant to patients. Metformin and insulin versus insulin alone did not significantly affect all cause mortality (relative risk 1.30, 95% confidence interval 0.57 to 2.99) or cardiovascular mortality (1.70, 0.35 to 8.30). Trial sequential analyses showed that more trials were needed before reliable conclusions could be drawn regarding these outcomes. In a fixed effect model, but not in a random effects model, severe hypoglycaemia was significantly more frequent with metformin and insulin than with insulin alone (2.83, 1.17 to 6.86). In a random effects model, metformin and insulin resulted in reduced Hb

  7. Meta-Analyses of QTLs Associated with Protein and Oil Contents and Compositions in Soybean [Glycine max (L.) Merr.] Seed.

    Science.gov (United States)

    Van, Kyujung; McHale, Leah K

    2017-06-01

    Soybean [ Glycine max (L.) Merr.] is a valuable and nutritious crop in part due to the high protein meal and vegetable oil produced from its seed. Soybean producers desire cultivars with both elevated seed protein and oil concentrations as well as specific amino acid and fatty acid profiles. Numerous studies have identified quantitative trait loci (QTLs) associated with seed composition traits, but validation of these QTLs has rarely been carried out. In this study, we have collected information, including genetic location and additive effects, on each QTL for seed contents of protein and oil, as well as amino acid and fatty acid compositions from over 80 studies. Using BioMercator V. 4.2, a meta-QTL analysis was performed with genetic information comprised of 175 QTLs for protein, 205 QTLs for oil, 156 QTLs for amino acids, and 113 QTLs for fatty acids. A total of 55 meta-QTL for seed composition were detected on 6 out of 20 chromosomes. Meta-QTL possessed narrower confidence intervals than the original QTL and candidate genes were identified within each meta-QTL. These candidate genes elucidate potential natural genetic variation in genes contributing to protein and oil biosynthesis and accumulation, providing meaningful information to further soybean breeding programs.

  8. Sleep, Cognition, and Behavioral Problems in School-Age Children: A Century of Research Meta-Analyzed

    NARCIS (Netherlands)

    Astill, R.G.; van der Heijden, K.B.; van IJzendoorn, M.H.; van Someren, E.J.W.

    2012-01-01

    Clear associations of sleep, cognitive performance, and behavioral problems have been demonstrated in meta-analyses of studies in adults. This meta-analysis is the first to systematically summarize all relevant studies reporting on sleep, cognition, and behavioral problems in healthy school-age

  9. Global Prevalence of Elder Abuse: A Meta-analysis and Meta-regression.

    Science.gov (United States)

    Ho, C Sh; Wong, S Y; Chiu, M M; Ho, R Cm

    2017-06-01

    Elder abuse is increasingly recognised as a global public health and social problem. There has been limited inter-study comparison of the prevalence and risk factors for elder abuse. This study aimed to estimate the pooled and subtype prevalence of elder abuse worldwide and identify significant associated risk factors. We conducted a meta-analysis and meta-regression of 34 population-based and 17 non-population-based studies. The pooled prevalences of elder abuse were 10.0% (95% confidence interval, 5.2%-18.6%) and 34.3% (95% confidence interval, 22.9%-47.8%) in population-based studies and third party- or caregiver-reported studies, respectively. Being in a marital relationship was found to be a significant moderator using random-effects model. This meta-analysis revealed that third parties or caregivers were more likely to report abuse than older abused adults. Subgroup analyses showed that females and those resident in non-western countries were more likely to be abused. Emotional abuse was the most prevalent elder abuse subtype and financial abuse was less commonly reported by third parties or caregivers. Heterogeneity in the prevalence was due to the high proportion of married older adults in the sample. Subgroup analysis showed that cultural factors, subtypes of abuse, and gender also contributed to heterogeneity in the pooled prevalence of elder abuse.

  10. Fruits, vegetables and lung cancer risk: a systematic review and meta-analysis.

    Science.gov (United States)

    Vieira, A R; Abar, L; Vingeliene, S; Chan, D S M; Aune, D; Navarro-Rosenblatt, D; Stevens, C; Greenwood, D; Norat, T

    2016-01-01

    Lung cancer is the most common cause of cancer death. Fruits and vegetables containing carotenoids and other antioxidants have been hypothesized to decrease lung cancer risk. As part of the World Cancer Research Fund International Continuous Update Project, we conducted a systematic review and meta-analysis of prospective studies. We searched PubMed and several databases up to December 2014 for prospective studies. We conducted meta-analyses comparing the highest and lowest intakes and dose-response meta-analyses to estimate summary relative risks (RRs) and 95% confidence intervals (CIs), and examine possible non-linear associations. We combined results from the Pooling Project with the studies we identified to increase the statistical power of our analysis. When comparing the highest with the lowest intakes, the summary RR estimates were 0.86 [95% CI 0.78-0.94; n (studies) = 18] for fruits and vegetables, 0.92 (95% CI 0.87-0.97; n = 25) for vegetables and 0.82 (95% CI 0.76-0.89; n = 29) for fruits. The association with fruit and vegetable intake was marginally significant in current smokers and inverse but not significant in former or never smokers. Significant inverse dose-response associations were observed for each 100 g/day increase: for fruits and vegetables [RR: 0.96; 95% CI 0.94-0.98, I(2) = 64%, n = 14, N (cases) = 9609], vegetables (RR: 0.94; 95% CI 0.89-0.98, I(2) = 48%, n = 20, N = 12 563) and fruits (RR: 0.92; 95% CI 0.89-0.95, I(2) = 57%, n = 23, N = 14 506). Our results were consistent among the different types of fruits and vegetables. The strength of the association differed across locations. There was evidence of a non-linear relationship (P fruit and vegetable intake and lung cancer risk showing that no further benefit is obtained when increasing consumption above ∼400 g per day. Eliminating tobacco smoking is the best strategy to prevent lung cancer. Although residual confounding by smoking cannot be ruled out, the current evidence from

  11. Moral development and recidivism: a meta-analysis

    NARCIS (Netherlands)

    van Vugt, E.; Gibbs, J.; Stams, G.J.; Bijleveld, C.; Hendriks, J.; van der Laan, P.

    2011-01-01

    A meta-analysis of 19 studies (N = 15,992 offenders) showed a significant inverse relation between more mature moral development and recidivism. Moderator analyses revealed a larger effect size for moral cognition (r = .20) than for moral emotion (r = .11). Effect sizes for production measures (r =

  12. Meta II: Multi-Model Language Suite for Cyber Physical Systems

    Science.gov (United States)

    2013-03-01

    AVM META) projects have developed tools for designing cyber physical (or Mechatronic ) Systems . These systems are increasingly complex, take much...projects have developed tools for designing cyber physical (CPS) (or Mechatronic ) systems . Exemplified by modern amphibious and ground military...and parametric interface of Simulink models and defines associations with CyPhy components and component interfaces. 2. Embedded Systems Modeling

  13. Rethinking individualism and collectivism: evaluation of theoretical assumptions and meta-analyses.

    Science.gov (United States)

    Oyserman, Daphna; Coon, Heather M; Kemmelmeier, Markus

    2002-01-01

    Are Americans more individualistic and less collectivistic than members of other groups? The authors summarize plausible psychological implications of individualism-collectivism (IND-COL), meta-analyze cross-national and within-United States IND-COL differences, and review evidence for effects of IND-COL on self-concept, well-being, cognition, and relationality. European Americans were found to be both more individualistic-valuing personal independence more-and less collectivistic-feeling duty to in-groups less-than others. However, European Americans were not more individualistic than African Americans, or Latinos, and not less collectivistic than Japanese or Koreans. Among Asians, only Chinese showed large effects, being both less individualistic and more collectivistic. Moderate IND-COL effects were found on self-concept and relationality, and large effects were found on attribution and cognitive style.

  14. Behavioural effects of advanced cruise control use : a meta-analytic approach.

    NARCIS (Netherlands)

    Dragutinovic, N. Brookhuis, K.A. Hagenzieker, M.P. & Marchau, V.A.W.J.

    2006-01-01

    In this study, a meta-analytic approach was used to analyse effects of Advanced Cruise Control (ACC) on driving behaviour reported in seven driving simulator studies. The effects of ACC on three consistent outcome measures, namely, driving speed, headway and driver workload have been analysed. The

  15. Activation and Shielding Analyses in Support of the GUINEVERE Project

    International Nuclear Information System (INIS)

    Serikov, A.; Fischer, U.; Mercatali, L.; Baeten, P.; Vittiglio, G.

    2008-01-01

    The GUINEVERE facility (Generator of Uninterrupted Intense Neutrons at the lead Venus Reactor) must satisfy the nuclear safety criteria required by the Belgian safety authority to be licensed. The radiation dose and activation analyses for the nuclear safety assessment of the GUINEVERE project were performed at FZK. The concerted efforts of several European institutions were concentrated on the development and construction of a subcritical fast lead core based on the Venus water moderated reactor at the SCK-CEN site in Mol, Belgium. A Monte Carlo (MC) MCNP5 model was developed in accordance with the current design of the GUINEVERE fast lead core. The analytical MC method does not work for shielding analysis of the GUINEVERE building because of the large size of the rooms and thick concrete walls and floors. MC variance reduction techniques, such as particles splitting, Russian roulette, and point detectors were therefore applied. The JEFF-3.1 nuclear data library was used for radiation transport calculations. The activation analyses for the lead core and building materials were performed with the FISPACT-2005 inventory code and the EAF-2005 library. The neutron and photon dose rate maps were produced using MCNP track-length estimations, point detectors, and a mesh tally superimposed over the GUINEVERE geometry. The effects of D-D and D-T fusion neutron sources were estimated. (authors)

  16. Activation and Shielding Analyses in Support of the GUINEVERE Project

    Energy Technology Data Exchange (ETDEWEB)

    Serikov, A.; Fischer, U.; Mercatali, L. [Association FZK-EURATOM, KIT, Forschungszentrum Karlsruhe, P.O. Box 3640, 76021 Karlsruhe (Germany); Baeten, P.; Vittiglio, G. [SCK-CEN, Boeretang 200, B-2400 Mol (Belgium)

    2008-07-01

    The GUINEVERE facility (Generator of Uninterrupted Intense Neutrons at the lead Venus Reactor) must satisfy the nuclear safety criteria required by the Belgian safety authority to be licensed. The radiation dose and activation analyses for the nuclear safety assessment of the GUINEVERE project were performed at FZK. The concerted efforts of several European institutions were concentrated on the development and construction of a subcritical fast lead core based on the Venus water moderated reactor at the SCK-CEN site in Mol, Belgium. A Monte Carlo (MC) MCNP5 model was developed in accordance with the current design of the GUINEVERE fast lead core. The analytical MC method does not work for shielding analysis of the GUINEVERE building because of the large size of the rooms and thick concrete walls and floors. MC variance reduction techniques, such as particles splitting, Russian roulette, and point detectors were therefore applied. The JEFF-3.1 nuclear data library was used for radiation transport calculations. The activation analyses for the lead core and building materials were performed with the FISPACT-2005 inventory code and the EAF-2005 library. The neutron and photon dose rate maps were produced using MCNP track-length estimations, point detectors, and a mesh tally superimposed over the GUINEVERE geometry. The effects of D-D and D-T fusion neutron sources were estimated. (authors)

  17. Reaffirmed limitations of meta-analytic methods in the study of mild traumatic brain injury: a response to Rohling et al.

    Science.gov (United States)

    Bigler, Erin D; Farrer, Thomas J; Pertab, Jon L; James, Kelly; Petrie, Jo Ann; Hedges, Dawson W

    2013-01-01

    In 2009 Pertab, James, and Bigler published a critique of two prior meta-analyses by Binder, Rohling, and Larrabee (1997) and Frencham, Fox, and Maybery (2005) that showed small effect size difference at least 3 months post-injury in individuals who had sustained a mild traumatic brain injury (mTBI). The Binder et al. and Frencham et al. meta-analyses have been widely cited as showing no lasting effect of mTBI. In their critique Pertab et al. (2009) point out many limitations of these two prior meta-analyses, demonstrating that depending on how inclusion/exclusion criteria were defined different meta-analytic findings occur, some supporting the persistence of neuropsychological impairments beyond 3 months. Rohling et al. (2011) have now critiqued Pertab et al. (2009). Herein we respond to the Rolling et al. (2011) critique reaffirming the original findings of Pertab et al. (2009), providing additional details concerning the flaws in prior meta-analytic mTBI studies and the effects on neuropsychological performance.

  18. The paradox of intragroup conflict: a meta-analysis.

    Science.gov (United States)

    de Wit, Frank R C; Greer, Lindred L; Jehn, Karen A

    2012-03-01

    Since the meta-analysis by De Dreu and Weingart (2003b) on the effects of intragroup conflict on group outcomes, more than 80 new empirical studies of conflict have been conducted, often investigating more complex, moderated relationships between conflict and group outcomes, as well as new types of intragroup conflict, such as process conflict. To explore the trends in this new body of literature, we conducted a meta-analysis of 116 empirical studies of intragroup conflict (n = 8,880 groups) and its relationship with group outcomes. To address the heterogeneity across the studies included in the meta-analysis, we also investigated a number of moderating variables. Stable negative relationships were found between relationship and process conflict and group outcomes. In contrast to the results of De Dreu and Weingart, we did not find a strong and negative association between task conflict and group performance. Analyses of main effects as well as moderator analyses revealed a more complex picture. Task conflict and group performance were more positively related among studies where the association between task and relationship conflict was relatively weak, in studies conducted among top management teams rather than non-top management teams, and in studies where performance was measured in terms of financial performance or decision quality rather than overall performance.

  19. Systematic reviews and meta-analyses on psoriasis: role of funding sources, conflict of interest and bibliometric indices as predictors of methodological quality.

    Science.gov (United States)

    Gómez-García, F; Ruano, J; Aguilar-Luque, M; Gay-Mimbrera, J; Maestre-Lopez, B; Sanz-Cabanillas, J L; Carmona-Fernández, P J; González-Padilla, M; Vélez García-Nieto, A; Isla-Tejera, B

    2017-06-01

    The quality of systematic reviews and meta-analyses on psoriasis, a chronic inflammatory skin disease that severely impairs quality of life and is associated with high costs, remains unknown. To assess the methodological quality of systematic reviews published on psoriasis. After a comprehensive search in MEDLINE, Embase and the Cochrane Database (PROSPERO: CDR42016041611), the quality of studies was assessed by two raters using the Assessment of Multiple Systematic Reviews (AMSTAR) tool. Article metadata and journal-related bibliometric indices were also obtained. Systematic reviews were classified as low (0-4), moderate (5-8) or high (9-11) quality. A prediction model for methodological quality was fitted using principal component and multivariate ordinal logistic regression analyses. We classified 220 studies as high (17·2%), moderate (55·0%) or low (27·8%) quality. Lower compliance rates were found for AMSTAR question (Q)5 (list of studies provided, 11·4%), Q10 (publication bias assessed, 27·7%), Q4 (status of publication included, 39·5%) and Q1 (a priori design provided, 40·9%). Factors such as meta-analysis inclusion [odds ratio (OR) 6·22; 95% confidence interval (CI) 2·78-14·86], funding by academic institutions (OR 2·90, 95% CI 1·11-7·89), Article Influence score (OR 2·14, 95% CI 1·05-6·67), 5-year impact factor (OR 1·34, 95% CI 1·02-1·40) and article page count (OR 1·08, 95% CI 1·02-1·15) significantly predicted higher quality. A high number of authors with a conflict of interest (OR 0·90, 95% CI 0·82-0·99) was significantly associated with lower quality. The methodological quality of systematic reviews published about psoriasis remains suboptimal. The type of funding sources and author conflicts may compromise study quality, increasing the risk of bias. © 2017 British Association of Dermatologists.

  20. Socioeconomic position, lifestyle factors and age at natural menopause: a systematic review and meta-analyses of studies across six continents

    Science.gov (United States)

    Schoenaker, Danielle AJM; Jackson, Caroline A; Rowlands, Jemma V; Mishra, Gita D

    2014-01-01

    Background: Age at natural menopause (ANM) is considered a marker of biological ageing and is increasingly recognized as a sentinel for chronic disease risk in later life. Socioeconomic position (SEP) and lifestyle factors are thought to be associated with ANM. Methods: We performed a systematic review and meta-analyses to determine the overall mean ANM, and the effect of SEP and lifestyle factors on ANM by calculating the weighted mean difference (WMD) and pooling adjusted hazard ratios. We explored heterogeneity using meta-regression and also included unpublished findings from the Australian Longitudinal Study on Women’s Health. Results: We identified 46 studies across 24 countries. Mean ANM was 48.8 years [95% confidence interval (CI): 48.3, 49.2], with between-study heterogeneity partly explained by geographical region. ANM was lowest among African, Latin American, Asian and Middle Eastern countries and highest in Europe and Australia, followed by the USA. Education was associated with later ANM (WMD middle vs low education 0.30, 95% CI: 0.10, 0.51; high vs low education 0.64, 95% CI 0.26, 1.02). A similar dose-response relationship was also observed for occupation. Smoking was associated with a 1-year reduction of ANM (WMD: -0.91, 95% CI: –1.34, –0.48). Being overweight and moderate/high physical activity were modestly associated with later ANM, but findings were less conclusive. Conclusions: ANM varies across populations, partly due to differences across geographical regions. SEP and some lifestyle factors are associated with ANM, but further research is needed to examine the impact of the associations between risk factors and ANM on future health outcomes. PMID:24771324

  1. Dielectric Meta-Holograms Enabled with Dual Magnetic Resonances in Visible Light.

    Science.gov (United States)

    Li, Zile; Kim, Inki; Zhang, Lei; Mehmood, Muhammad Q; Anwar, Muhammad S; Saleem, Murtaza; Lee, Dasol; Nam, Ki Tae; Zhang, Shuang; Luk'yanchuk, Boris; Wang, Yu; Zheng, Guoxing; Rho, Junsuk; Qiu, Cheng-Wei

    2017-09-26

    Efficient transmission-type meta-holograms have been demonstrated using high-index dielectric nanostructures based on Huygens' principle. It is crucial that the geometry size of building blocks be judiciously optimized individually for spectral overlap of electric and magnetic dipoles. In contrast, reflection-type meta-holograms using the metal/insulator/metal scheme and geometric phase can be readily achieved with high efficiency and small thickness. Here, we demonstrate a general platform for design of dual magnetic resonance based meta-holograms based on the geometric phase using silicon nanostructures that are quarter wavelength thick for visible light. Significantly, the projected holographic image can be unambiguously observed without a receiving screen even under the illumination of natural light. Within the well-developed semiconductor industry, our ultrathin magnetic resonance-based meta-holograms may have promising applications in anticounterfeiting and information security.

  2. Comparison of nuisance parameters in pediatric versus adult randomized trials: a meta-epidemiologic empirical evaluation

    NARCIS (Netherlands)

    Vandermeer, Ben; van der Tweel, Ingeborg; Jansen-van der Weide, Marijke C.; Weinreich, Stephanie S.; Contopoulos-Ioannidis, Despina G.; Bassler, Dirk; Fernandes, Ricardo M.; Askie, Lisa; Saloojee, Haroon; Baiardi, Paola; Ellenberg, Susan S.; van der Lee, Johanna H.

    2018-01-01

    Background: We wished to compare the nuisance parameters of pediatric vs. adult randomized-trials (RCTs) and determine if the latter can be used in sample size computations of the former. Methods: In this meta-epidemiologic empirical evaluation we examined meta-analyses from the Cochrane Database of

  3. Pleiotropic Meta-Analyses of Longitudinal Studies Discover Novel Genetic Variants Associated with Age-Related Diseases

    Directory of Open Access Journals (Sweden)

    Liang He

    2016-10-01

    Full Text Available Age-related diseases may result from shared biological mechanisms in intrinsic processes of aging. Genetic effects on age-related diseases are often modulated by environmental factors due to their little contribution to fitness or are mediated through certain endophenotypes. Identification of genetic variants with pleiotropic effects on both common complex diseases and endophenotypes may reveal potential conflicting evolutionary pressures and deliver new insights into shared genetic contribution to healthspan and lifespan. Here, we performed pleiotropic meta-analyses of genetic variants using five NIH-funded datasets by integrating univariate summary statistics for age-related diseases and endophenotypes. We investigated three groups of traits: (1 endophenotypes such as blood glucose, blood pressure, lipids, hematocrit, and body mass index, (2 time-to-event outcomes such as the age-at-onset of diabetes mellitus (DM, cancer, cardiovascular diseases (CVDs and neurodegenerative diseases (NDs, and (3 both combined. In addition to replicating previous findings, we identify seven novel genome-wide significant loci (< 5e-08, out of which five are low-frequency variants. Specifically, from Group 2, we find rs7632505 on 3q21.1 in SEMA5B, rs460976 on 21q22.3 (1 kb from TMPRSS2 and rs12420422 on 11q24.1 predominantly associated with a variety of CVDs, rs4905014 in ITPK1 associated with stroke and heart failure, rs7081476 on 10p12.1 in ANKRD26 associated with multiple diseases including DM, CVDs, and NDs. From Group 3, we find rs8082812 on 18p11.22 and rs1869717 on 4q31.3 associated with both endophenotypes and CVDs. Our follow-up analyses show that rs7632505, rs4905014, and rs8082812 have age-dependent effects on coronary heart disease or stroke. Functional annotation suggests that most of these SNPs are within regulatory regions or DNase clusters and in linkage disequilibrium with expression quantitative trait loci, implying their potential regulatory

  4. Ataxia Telangiectasia–Mutated Gene Polymorphisms and Acute Normal Tissue Injuries in Cancer Patients After Radiation Therapy: A Systematic Review and Meta-analysis

    International Nuclear Information System (INIS)

    Dong, Lihua; Cui, Jingkun; Tang, Fengjiao; Cong, Xiaofeng; Han, Fujun

    2015-01-01

    Purpose: Studies of the association between ataxia telangiectasia–mutated (ATM) gene polymorphisms and acute radiation injuries are often small in sample size, and the results are inconsistent. We conducted the first meta-analysis to provide a systematic review of published findings. Methods and Materials: Publications were identified by searching PubMed up to April 25, 2014. Primary meta-analysis was performed for all acute radiation injuries, and subgroup meta-analyses were based on clinical endpoint. The influence of sample size and radiation injury incidence on genetic effects was estimated in sensitivity analyses. Power calculations were also conducted. Results: The meta-analysis was conducted on the ATM polymorphism rs1801516, including 5 studies with 1588 participants. For all studies, the cut-off for differentiating cases from controls was grade 2 acute radiation injuries. The primary meta-analysis showed a significant association with overall acute radiation injuries (allelic model: odds ratio = 1.33, 95% confidence interval: 1.04-1.71). Subgroup analyses detected an association between the rs1801516 polymorphism and a significant increase in urinary and lower gastrointestinal injuries and an increase in skin injury that was not statistically significant. There was no between-study heterogeneity in any meta-analyses. In the sensitivity analyses, small studies did not show larger effects than large studies. In addition, studies with high incidence of acute radiation injuries showed larger effects than studies with low incidence. Power calculations revealed that the statistical power of the primary meta-analysis was borderline, whereas there was adequate power for the subgroup analysis of studies with high incidence of acute radiation injuries. Conclusions: Our meta-analysis showed a consistency of the results from the overall and subgroup analyses. We also showed that the genetic effect of the rs1801516 polymorphism on acute radiation injuries was

  5. Rhetorical meta-language to promote the development of students' writing skills and subject matter understanding

    Science.gov (United States)

    Pelger, Susanne; Sigrell, Anders

    2016-01-01

    Background: Feedback is one of the most significant factors for students' development of writing skills. For feedback to be successful, however, students and teachers need a common language - a meta-language - for discussing texts. Not least because in science education such a meta-language might contribute to improve writing training and feedback-giving. Purpose: The aim of this study was to explore students' perception of teachers' feedback given on their texts in two genres, and to suggest how writing training and feedback-giving could become more efficient. Sample: In this study were included 44 degree project students in biology and molecular biology, and 21 supervising teachers at a Swedish university. Design and methods: The study concerned students' writing about their degree projects in two genres: scientific writing and popular science writing. The data consisted of documented teacher feedback on the students' popular science texts. It also included students' and teachers' answers to questionnaires about writing and feedback. All data were collected during the spring of 2012. Teachers' feedback, actual and recalled - by students and teachers, respectively - was analysed and compared using the so-called Canons of rhetoric. Results: While the teachers recalled the given feedback as mainly positive, most students recalled only negative feedback. According to the teachers, suggested improvements concerned firstly the content, and secondly the structure of the text. In contrast, the students mentioned language style first, followed by content. Conclusions: The disagreement between students and teachers regarding how and what feedback was given on the students texts confirm the need of improved strategies for writing training and feedback-giving in science education. We suggest that the rhetorical meta-language might play a crucial role in overcoming the difficulties observed in this study. We also discuss how training of writing skills may contribute to

  6. [The meta-analysis of data from individual patients].

    NARCIS (Netherlands)

    Rovers, M.M.; Reitsma, J.B.

    2012-01-01

    - An IPD (Individual Participant Data) meta-analysis requires collecting original individual patient data and calculating an estimated effect based on these data.- The use of individual patient data has various advantages: the original data and the results of published analyses are verified,

  7. The Efficacy of Mindfulness-Based Interventions in Primary Care: A Meta-Analytic Review.

    Science.gov (United States)

    Demarzo, Marcelo M P; Montero-Marin, Jesús; Cuijpers, Pim; Zabaleta-del-Olmo, Edurne; Mahtani, Kamal R; Vellinga, Akke; Vicens, Caterina; López-del-Hoyo, Yolanda; García-Campayo, Javier

    2015-11-01

    Positive effects have been reported after mindfulness-based interventions (MBIs) in diverse clinical and nonclinical populations. Primary care is a key health care setting for addressing common chronic conditions, and an effective MBI designed for this setting could benefit countless people worldwide. Meta-analyses of MBIs have become popular, but little is known about their efficacy in primary care. Our aim was to investigate the application and efficacy of MBIs that address primary care patients. We performed a meta-analytic review of randomized controlled trials addressing the effect of MBIs in adult patients recruited from primary care settings. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Cochrane guidelines were followed. Effect sizes were calculated with the Hedges g in random effects models. The meta-analyses were based on 6 trials having a total of 553 patients. The overall effect size of MBI compared with a control condition for improving general health was moderate (g = 0.48; P = .002), with moderate heterogeneity (I(2) = 59; P .05). Although the number of randomized controlled trials applying MBIs in primary care is still limited, our results suggest that these interventions are promising for the mental health and quality of life of primary care patients. We discuss innovative approaches for implementing MBIs, such as complex intervention and stepped care. © 2015 Annals of Family Medicine, Inc.

  8. Nutritional support in chronic obstructive pulmonary disease: a systematic review and meta-analysis.

    Science.gov (United States)

    Collins, Peter F; Stratton, Rebecca J; Elia, Marinos

    2012-06-01

    The efficacy of nutritional support in the management of malnutrition in chronic obstructive pulmonary disease (COPD) is controversial. Previous meta-analyses, based on only cross-sectional analysis at the end of intervention trials, found no evidence of improved outcomes. The objective was to conduct a meta-analysis of randomized controlled trials (RCTs) to clarify the efficacy of nutritional support in improving intake, anthropometric measures, and grip strength in stable COPD. Literature databases were searched to identify RCTs comparing nutritional support with controls in stable COPD. Thirteen RCTs (n = 439) of nutritional support [dietary advice (1 RCT), oral nutritional supplements (ONS; 11 RCTs), and enteral tube feeding (1 RCT)] with a control comparison were identified. An analysis of the changes induced by nutritional support and those obtained only at the end of the intervention showed significantly greater increases in mean total protein and energy intakes with nutritional support of 14.8 g and 236 kcal daily. Meta-analyses also showed greater mean (±SE) improvements in favor of nutritional support for body weight (1.94 ± 0.26 kg, P groups. This systematic review and meta-analysis showed that nutritional support, mainly in the form of ONS, improves total intake, anthropometric measures, and grip strength in COPD. These results contrast with the results of previous analyses that were based on only cross-sectional measures at the end of intervention trials.

  9. [Meta-analyses on measurement precision of non-invasive hemodynamic monitoring technologies in adults].

    Science.gov (United States)

    Pestel, G; Fukui, K; Higashi, M; Schmidtmann, I; Werner, C

    2018-06-01

    An ideal non-invasive monitoring system should provide accurate and reproducible measurements of clinically relevant variables that enables clinicians to guide therapy accordingly. The monitor should be rapid, easy to use, readily available at the bedside, operator-independent, cost-effective and should have a minimal risk and side effect profile for patients. An example is the introduction of pulse oximetry, which has become established for non-invasive monitoring of oxygenation worldwide. A corresponding non-invasive monitoring of hemodynamics and perfusion could optimize the anesthesiological treatment to the needs in individual cases. In recent years several non-invasive technologies to monitor hemodynamics in the perioperative setting have been introduced: suprasternal Doppler ultrasound, modified windkessel function, pulse wave transit time, radial artery tonometry, thoracic bioimpedance, endotracheal bioimpedance, bioreactance, and partial CO 2 rebreathing have been tested for monitoring cardiac output or stroke volume. The photoelectric finger blood volume clamp technique and respiratory variation of the plethysmography curve have been assessed for monitoring fluid responsiveness. In this manuscript meta-analyses of non-invasive monitoring technologies were performed when non-invasive monitoring technology and reference technology were comparable. The primary evaluation criterion for all studies screened was a Bland-Altman analysis. Experimental and pediatric studies were excluded, as were all studies without a non-invasive monitoring technique or studies without evaluation of cardiac output/stroke volume or fluid responsiveness. Most studies found an acceptable bias with wide limits of agreement. Thus, most non-invasive hemodynamic monitoring technologies cannot be considered to be equivalent to the respective reference method. Studies testing the impact of non-invasive hemodynamic monitoring technologies as a trend evaluation on outcome, as well as

  10. The evaluation of meta-analysis techniques for quantifying prescribed fire effects on fuel loadings.

    Science.gov (United States)

    Karen E. Kopper; Donald McKenzie; David L. Peterson

    2009-01-01

    Models and effect-size metrics for meta-analysis were compared in four separate meta-analyses quantifying surface fuels after prescribed fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the Western United States. An aggregated data set was compiled from eight published reports that contained data from 65 fire treatment units....

  11. Multidisciplinary Geo-scientific Hazard Analyses: Istanbul Microzonation Projects

    Science.gov (United States)

    Kara, Sema; Baş, Mahmut; Kılıç, Osman; Tarih, Ahmet; Yahya Menteşe, Emin; Duran, Kemal

    2017-04-01

    Istanbul (Turkey) is located on the west edge of North Anatolia Fault and hence is an earthquake prone city with a population that exceeds 15 million people. In addition, the city is still growing as center of commerce, tourism and culture that increases the exposure more and more. During the last decade, although Istanbul grew faster than ever in its history, precautions against a possible earthquake have also increased steadily. The two big earthquakes (in Kocaeli and Duzce Provinces) occurred in 1999 alongside Istanbul and these events became the trigger events that accelerated the disaster risk reduction activities in Istanbul. Following a loss estimation study carried out by Japanese International Cooperation Agency (JICA) in 2001 and Istanbul Earthquake Master Plan prepared by four major universities' researchers in 2003; it was evaluated that understanding and analyzing the geological structure in Istanbul was the main concern. Thereafter Istanbul Metropolitan Municipality's Directorate of Earthquake and Ground Research (DEGRE) carried out two major geo-scientific studies called "microzonation studies" covering 650 km2 of Istanbul's urbanized areas between 2006 and 2009. The studies were called "microzonation" because the analysis resolution was as dense as 250m grids and included various assessments on hazards such as ground shaking, liquefaction, karstification, landslide, flooding, and surface faulting. After the evaluation of geological, geotechnical and geophysical measurements; Earthquake and Tsunami Hazard Maps for all Istanbul, slope, engineering geology, ground water level, faulting, ground shaking, inundation, shear wave velocity and soil classification maps for the project areas were obtained. In the end "Land Suitability Maps" are derived from the combination of inputs using multi-hazard approach. As a result, microzonation is tool for risk oriented urban planning; consisting of interdisciplinary multi-hazard risk analyses. The outputs of

  12. Vitamin D and Depression: A Systematic Review and Meta-Analysis Comparing Studies with and without Biological Flaws

    Directory of Open Access Journals (Sweden)

    Simon Spedding

    2014-04-01

    Full Text Available Efficacy of Vitamin D supplements in depression is controversial, awaiting further literature analysis. Biological flaws in primary studies is a possible reason meta-analyses of Vitamin D have failed to demonstrate efficacy. This systematic review and meta-analysis of Vitamin D and depression compared studies with and without biological flaws. The systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA guidelines. The literature search was undertaken through four databases for randomized controlled trials (RCTs. Studies were critically appraised for methodological quality and biological flaws, in relation to the hypothesis and study design. Meta-analyses were performed for studies according to the presence of biological flaws. The 15 RCTs identified provide a more comprehensive evidence-base than previous systematic reviews; methodological quality of studies was generally good and methodology was diverse. A meta-analysis of all studies without flaws demonstrated a statistically significant improvement in depression with Vitamin D supplements (+0.78 CI +0.24, +1.27. Studies with biological flaws were mainly inconclusive, with the meta-analysis demonstrating a statistically significant worsening in depression by taking Vitamin D supplements (−1.1 CI −0.7, −1.5. Vitamin D supplementation (≥800 I.U. daily was somewhat favorable in the management of depression in studies that demonstrate a change in vitamin levels, and the effect size was comparable to that of anti-depressant medication.

  13. Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods

    DEFF Research Database (Denmark)

    Jakobsen, Janus Christian; Wetterslev, Jorn; Winkel, Per

    2014-01-01

    BACKGROUND: Thresholds for statistical significance when assessing meta-analysis results are being insufficiently demonstrated by traditional 95% confidence intervals and P-values. Assessment of intervention effects in systematic reviews with meta-analysis deserves greater rigour. METHODS......: Methodologies for assessing statistical and clinical significance of intervention effects in systematic reviews were considered. Balancing simplicity and comprehensiveness, an operational procedure was developed, based mainly on The Cochrane Collaboration methodology and the Grading of Recommendations...... Assessment, Development, and Evaluation (GRADE) guidelines. RESULTS: We propose an eight-step procedure for better validation of meta-analytic results in systematic reviews (1) Obtain the 95% confidence intervals and the P-values from both fixed-effect and random-effects meta-analyses and report the most...

  14. A systematic review and meta-analyses on C-reactive protein in relation to periodontitis.

    Science.gov (United States)

    Paraskevas, Spiros; Huizinga, John D; Loos, Bruno G

    2008-04-01

    Elevated plasma C-reactive protein (CRP) is regarded as a risk predictor for cardiovascular diseases. This systematic review explored the robustness of observations that CRP is elevated in periodontitis. Similarly, the effect of periodontal therapy on CRP levels was investigated. Selection of publications was based on: (1) cross-sectional (case-control) studies; (2) longitudinal (treatment) studies; (3) high-sensitivity CRP measurement; (4) median and/or mean (+/-SD) values presented; and (5) subjects with no systemic disorders. Screening of the initially 448 identified studies and reference checking resulted in 18 suitable papers. The majority of the studies showed that CRP levels are higher in patients than in controls. Often, studies showed that patients had CRP levels >2.1 mg/l. A meta-analysis of 10 cross-sectional studies showed that the weighted mean difference (WMD) of CRP between patients and controls was 1.56 mg/l (pperiodontal therapy. Eligible treatment studies in a meta-analysis demonstrated a WMD of reductions of CRP after therapy of 0.50 mg/L (95% CI 0.08-0.93) (p=0.02). There is strong evidence from cross-sectional studies that plasma CRP in periodontitis is elevated compared with controls. There is modest evidence on the effect of periodontal therapy in lowering the levels of CRP.

  15. Comparison of High, Intermediate, and Low Frequency Shock Wave Lithotripsy for Urinary Tract Stone Disease: Systematic Review and Network Meta-Analysis.

    Science.gov (United States)

    Kang, Dong Hyuk; Cho, Kang Su; Ham, Won Sik; Lee, Hyungmin; Kwon, Jong Kyou; Choi, Young Deuk; Lee, Joo Yong

    2016-01-01

    To perform a systematic review and network meta-analysis of randomized controlled trials (RCTs) to determine the optimal shock wave lithotripsy (SWL) frequency range for treating urinary stones, i.e., high-frequency (100-120 waves/minute), intermediate-frequency (80-90 waves/minute), and low-frequency (60-70 waves/minute) lithotripsy. Relevant RCTs were identified from electronic databases for meta-analysis of SWL success and complication rates. Using pairwise and network meta-analyses, comparisons were made by qualitative and quantitative syntheses. Outcome variables are provided as odds ratios (ORs) with 95% confidence intervals (CIs). Thirteen articles were included in the qualitative and quantitative synthesis using pairwise and network meta-analyses. On pairwise meta-analyses, comparable inter-study heterogeneity was observed for the success rate. On network meta-analyses, the success rates of low- (OR 2.2; 95% CI 1.5-2.6) and intermediate-frequency SWL (OR 2.5; 95% CI 1.3-4.6) were higher than high-frequency SWL. Forest plots from the network meta-analysis showed no significant differences in the success rate between low-frequency SWL versus intermediate-frequency SWL (OR 0.87; 95% CI 0.51-1.7). There were no differences in complication rate across different SWL frequency ranges. By rank-probability testing, intermediate-frequency SWL was ranked highest for success rate, followed by low-frequency and high-frequency SWL. Low-frequency SWL was also ranked highest for low complication rate, with high- and intermediate-frequency SWL ranked lower. Intermediate- and low-frequency SWL have better treatment outcomes than high-frequency SWL when considering both efficacy and complication.

  16. HOW HEALTHY IS THE BEHAVIOR OF YOUNG ATHLETES? A SYSTEMATIC LITERATURE REVIEW AND META-ANALYSES

    Directory of Open Access Journals (Sweden)

    Katharina Diehl

    2012-06-01

    Full Text Available Participation in sports during adolescence is considered a healthy behavior. The extent to which adolescent athletes engage in other healthful (or risky behaviors is less clear, however. We conducted a systematic literature review following the PRISMA Statement to assess the frequency of risky behaviors among athletes in this age group. We searched the PubMed, PsycINFO and SCA Sociological Abstracts databases for observational studies published in English over the last twenty years on the frequency of selected risk behaviors (alcohol consumption, smoking behavior, use of illicit drugs, unhealthy nutrition, and doping in adolescent athletes. Two independent reviewers selected articles following the PRISMA Statement. Behavior frequency was assessed as was comparability of study design and methods. When possible, meta- analyses were performed using data from subgroups of studies in which operational indicators were comparable. Seventy-eight articles met eligibility criteria. Although report of risky behaviors varied across studies, we observed overall, that studies tend to report higher alcohol use, less smoking, less recreational drug use, and more smokeless tobacco use in (high-involved athletes. Considerable heterogeneity was noted in study design, definition of target groups and use of operational indicators (I² ranged from 93.2% to 100%. Especially the higher prevalence of using alcohol and smokeless tobacco needs more attention in interventions targeted to this group. Overall, greater consensus on methods used to assess risky behaviors in adolescent athletes

  17. Meta-analysis of the effectiveness of psychological and medical treatments for binge-eating disorder (MetaBED): study protocol.

    Science.gov (United States)

    Hilbert, Anja; Petroff, David; Herpertz, Stephan; Kersting, Anette; Pietrowsky, Reinhard; Tuschen-Caffier, Brunna; Vocks, Silja; Schmidt, Ricarda

    2017-03-29

    Binge-eating disorder (BED) was included as its own diagnostic entity in the Fifth Edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). An increasing number of treatment studies have been published, but an up-to-date comprehensive meta-analysis on diverse treatment approaches for BED is lacking. In an updated and extension of a previous meta-analysis, the goals of this study are to assess the short-term and long-term effectiveness of psychological and medical treatments for BED. We will search bibliographic databases and study registries, including manual searches for studies published before January 2016. The search strategy will include terms relating to binge eating and diverse forms of psychological and medical interventions. Language will be restricted to English. The studies included will be treatment studies, that is, randomised-controlled trials, and non-randomised and non-controlled studies, for individuals with BED (DSM-IV or DSM-5), and studies that provided a pre-treatment and at least one post-treatment or follow-up assessment of binge eating. The primary outcomes will be the number of binge-eating episodes, abstinence from binge eating and diagnosis of BED at post-treatment and/or follow-up(s), and changes from pre-treatment to post-treatment and/or follow-up(s). Likewise, as secondary outcomes, eating disorder and general psychopathology, quality of life, and body weight will be analysed and adverse events and treatment drop-out will be examined. Study search, selection and data extraction, including risk of bias assessment, will be independently performed by 2 reviewers and consensus will be sought. Moderator analyses will be conducted, and equity aspects will be considered. Sensitivity analyses will be conducted to determine the robustness of the results. Ethical approval is not required for this meta-analysis. Published in a peer-reviewed journal and disseminated electronically and in print, this meta-analysis will form

  18. A critical appraisal of the use of umbilical artery Doppler ultrasound in high-risk pregnancies: use of meta-analyses in evidence-based obstetrics

    DEFF Research Database (Denmark)

    Westergaard, H.B.; Langhoff-Roos, J.; Lingman, G.

    2001-01-01

    Doppler velocimetry; high-risk pregnancy; meta-analysis; intrauterine growth restriction; perinatal mortality; umbilical artery......Doppler velocimetry; high-risk pregnancy; meta-analysis; intrauterine growth restriction; perinatal mortality; umbilical artery...

  19. Simulation-based power calculations for planning a two-stage individual participant data meta-analysis.

    Science.gov (United States)

    Ensor, Joie; Burke, Danielle L; Snell, Kym I E; Hemming, Karla; Riley, Richard D

    2018-05-18

    Researchers and funders should consider the statistical power of planned Individual Participant Data (IPD) meta-analysis projects, as they are often time-consuming and costly. We propose simulation-based power calculations utilising a two-stage framework, and illustrate the approach for a planned IPD meta-analysis of randomised trials with continuous outcomes where the aim is to identify treatment-covariate interactions. The simulation approach has four steps: (i) specify an underlying (data generating) statistical model for trials in the IPD meta-analysis; (ii) use readily available information (e.g. from publications) and prior knowledge (e.g. number of studies promising IPD) to specify model parameter values (e.g. control group mean, intervention effect, treatment-covariate interaction); (iii) simulate an IPD meta-analysis dataset of a particular size from the model, and apply a two-stage IPD meta-analysis to obtain the summary estimate of interest (e.g. interaction effect) and its associated p-value; (iv) repeat the previous step (e.g. thousands of times), then estimate the power to detect a genuine effect by the proportion of summary estimates with a significant p-value. In a planned IPD meta-analysis of lifestyle interventions to reduce weight gain in pregnancy, 14 trials (1183 patients) promised their IPD to examine a treatment-BMI interaction (i.e. whether baseline BMI modifies intervention effect on weight gain). Using our simulation-based approach, a two-stage IPD meta-analysis has meta-analysis was appropriate. Pre-specified adjustment for prognostic factors would increase power further. Incorrect dichotomisation of BMI would reduce power by over 20%, similar to immediately throwing away IPD from ten trials. Simulation-based power calculations could inform the planning and funding of IPD projects, and should be used routinely.

  20. Meta-learning framework applied in bioinformatics inference system design.

    Science.gov (United States)

    Arredondo, Tomás; Ormazábal, Wladimir

    2015-01-01

    This paper describes a meta-learner inference system development framework which is applied and tested in the implementation of bioinformatic inference systems. These inference systems are used for the systematic classification of the best candidates for inclusion in bacterial metabolic pathway maps. This meta-learner-based approach utilises a workflow where the user provides feedback with final classification decisions which are stored in conjunction with analysed genetic sequences for periodic inference system training. The inference systems were trained and tested with three different data sets related to the bacterial degradation of aromatic compounds. The analysis of the meta-learner-based framework involved contrasting several different optimisation methods with various different parameters. The obtained inference systems were also contrasted with other standard classification methods with accurate prediction capabilities observed.

  1. Psychopathology in children with epilepsy: a meta-analysis

    NARCIS (Netherlands)

    Rodenburg, R.; Stams, G.J.; Meijer, A.M.; Aldenkamp, A.P.; Dekovic, M.

    2005-01-01

    Objective To examine the types and severity of psychopathology in children with epilepsy. Methods A series of meta-analyses were conducted to review 46 studies, including 2,434 children with epilepsy. Results Effect sizes were medium to large for comparisons with children from the general

  2. Rhythm vs. rate control of atrial fibrillation meta-analysed by number needed to treat

    OpenAIRE

    Kumana, Cyrus R; Cheung, Bernard M Y; Cheung, Giselle T Y; Ovedal, Tori; Pederson, Bjorn; Lauder, Ian J

    2005-01-01

    Background: Whenever feasible, rhythm control of atrial fibrillation (AF) was generally preferred over rate control, in the belief that it offered better symptomatic relief and quality of life, and eliminated the need for anticoagulation. However, recent trials appear to challenge these assumptions. Aims: To explore the desirability of rhythm vs. rate control of AF by systematic review of pertinent, published, randomized controlled trials (RCTs) and a meta-analysis by number needed to treat (...

  3. Pharmacogenetics of clozapine response and induced weight gain: A comprehensive review and meta-analysis.

    Science.gov (United States)

    Gressier, Florence; Porcelli, Stefano; Calati, Raffaella; Serretti, Alessandro

    2016-02-01

    Clozapine (CLZ) is the prototype atypical antipsychotic and it has many advantages over other antipsychotic drugs. Several data suggest that both CLZ response and induced weight gain are strongly determined by genetic variability. However, results remain mainly inconclusive. We aim to review the literature data about pharmacogenetics studies on CLZ efficacy, focusing on pharmacodynamic genes. Further, we performed meta-analyses on response when at least three studies for each polymorphism were available. Sensitivity analyses were conducted on Caucasian population when feasible. Electronic literature search was performed to identify pertinent studies published until May 2014 using PubMed, ISI Web of Knowledge and PsycINFO databases. For meta-analyses, data were entered and analyzed through RevMan version 5.2 using a random-effect model. Our literature search yielded 9266 articles on CLZ; among these, we identified 59 pertinent pharmacogenetic studies. Genotype data were retrieved for 14 polymorphisms in 9 genes. Among these, we had available data from at least three independent samples for 8 SNPs in 6 genes to perform meta-analyses: DRD2 rs1799732, DRD3 rs6280, HTR2A rs6313, rs6311, rs6314, HTR2C rs6318, HTR3A rs1062613, TNFa rs1800629. Although literature review provided conflicting results, in meta-analyses three genetic variants within serotonin genes resulted associated to CLZ response: rs6313 and rs6314 within HTR2A gene and rs1062613 within HT3A gene. On the other hand, no clear finding emerged for CLZ-induced weight gain. Our results suggest a possible serotonergic modulation of CLZ clinical response. Copyright © 2015 Elsevier B.V. and ECNP. All rights reserved.

  4. Acceptance and commitment therapy - Do we know enough? Cumulative and sequential meta-analyses of randomized controlled trials.

    Science.gov (United States)

    Hacker, Thomas; Stone, Paul; MacBeth, Angus

    2016-01-15

    Acceptance and Commitment Therapy (ACT) has accrued a substantial evidence base. Recent systematic and meta-analytic reviews suggest that ACT is effective compared to control conditions. However, these reviews appraise the efficacy of ACT across a broad range of presenting problems, rather than addressing specific common mental health difficulties. Focussing on depression and anxiety we performed a meta-analysis of trials of ACT. We incorporated sequential meta-analysis (SMA) techniques to critically appraise the sufficiency of the existing evidence base. Findings suggest that ACT demonstrates at least moderate group and pre-post effects for symptom reductions for both anxiety and depression. However using SMA findings are more qualified. There is currently insufficient evidence to confidently conclude that ACT for anxiety is efficacious when compared to active control conditions or as primary treatment for anxiety. Similarly, using SMA, there is currently insufficient evidence to suggest a moderate efficacy of ACT for depression compared to active control conditions. To stimulate further research we offer specific estimates of additional numbers of participants required to reach sufficiency to help inform future studies. We also discuss the appropriate strategies for future research into ACT for anxiety given the current evidence suggests no differential efficacy of ACT in the treatment of anxiety compared to active control conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  5. Aspirin in the Treatment of Cancer: Reductions in Metastatic Spread and in Mortality: A Systematic Review and Meta-Analyses of Published Studies

    Science.gov (United States)

    Elwood, Peter C.

    2016-01-01

    Background Low-dose aspirin has been shown to reduce the incidence of cancer, but its role in the treatment of cancer is uncertain. Objectives We conducted a systematic search of the scientific literature on aspirin taken by patients following a diagnosis of cancer, together with appropriate meta-analyses. Methods Searches were completed in Medline and Embase in December 2015 using a pre-defined search strategy. References and abstracts of all the selected papers were scanned and expert colleagues were contacted for additional studies. Two reviewers applied pre-determined eligibility criteria (cross-sectional, cohort and controlled studies, and aspirin taken after a diagnosis of cancer), assessed study quality and extracted data on cancer cause-specific deaths, overall mortality and incidence of metastases. Random effects meta-analyses and planned sub-group analyses were completed separately for observational and experimental studies. Heterogeneity and publication bias were assessed in sensitivity analyses and appropriate omissions made. Papers were examined for any reference to bleeding and authors of the papers were contacted and questioned. Results Five reports of randomised trials were identified, together with forty two observational studies: sixteen on colorectal cancer, ten on breast and ten on prostate cancer mortality. Pooling of eleven observational reports of the effect of aspirin on cause-specific mortality from colon cancer, after the omission of one report identified on the basis of sensitivity analyses, gave a hazard ratio (HR) of 0.76 (95% CI 0.66, 0.88) with reduced heterogeneity (P = 0.04). The cause specific mortality in five reports of patients with breast cancer showed significant heterogeneity (Paspirin, and in five the effect is statistically significant. There were no significant differences between the pooled HRs for the three main cancers and after the omission of three reports already identified in sensitivity analyses heterogeneity was

  6. Coupling reduction between dipole antenna elements by using a planar meta-surface

    DEFF Research Database (Denmark)

    Saenz, Elena; Ederra, Inigo; Gonzalo, Ramon

    2009-01-01

    The mutual coupling between dipole antenna array elements using a planar meta-surface as superstrate is experimentally investigated. The meta-surface is based on grids of short metal strips and continuous wires. A comparison between the mutual coupling when the dipoles are radiating in free space...... driven dipole is fed and the others are matched with 50 Omega loads. The back-projected field on the aperture and on the E-plane is shown....

  7. MetaMeta: integrating metagenome analysis tools to improve taxonomic profiling.

    Science.gov (United States)

    Piro, Vitor C; Matschkowski, Marcel; Renard, Bernhard Y

    2017-08-14

    Many metagenome analysis tools are presently available to classify sequences and profile environmental samples. In particular, taxonomic profiling and binning methods are commonly used for such tasks. Tools available among these two categories make use of several techniques, e.g., read mapping, k-mer alignment, and composition analysis. Variations on the construction of the corresponding reference sequence databases are also common. In addition, different tools provide good results in different datasets and configurations. All this variation creates a complicated scenario to researchers to decide which methods to use. Installation, configuration and execution can also be difficult especially when dealing with multiple datasets and tools. We propose MetaMeta: a pipeline to execute and integrate results from metagenome analysis tools. MetaMeta provides an easy workflow to run multiple tools with multiple samples, producing a single enhanced output profile for each sample. MetaMeta includes a database generation, pre-processing, execution, and integration steps, allowing easy execution and parallelization. The integration relies on the co-occurrence of organisms from different methods as the main feature to improve community profiling while accounting for differences in their databases. In a controlled case with simulated and real data, we show that the integrated profiles of MetaMeta overcome the best single profile. Using the same input data, it provides more sensitive and reliable results with the presence of each organism being supported by several methods. MetaMeta uses Snakemake and has six pre-configured tools, all available at BioConda channel for easy installation (conda install -c bioconda metameta). The MetaMeta pipeline is open-source and can be downloaded at: https://gitlab.com/rki_bioinformatics .

  8. Meta-analysis identifies common and rare variants influencing blood pressure and overlapping with metabolic trait loci

    NARCIS (Netherlands)

    Liu, C. (Chunyu); A. Kraja (Aldi); J.A. Smith (Jennifer A); J. Brody (Jennifer); N. Franceschini (Nora); J.C. Bis (Joshua); K.M. Rice (Kenneth); A.C. Morrison (Alanna); Y. Lu (Yingchang); Weiss, S. (Stefan); X. Guo (Xiuqing); W. Palmas (Walter); L.W. Martin (Lisa); Y.D. Chen (Y.); Surendran, P. (Praveen); F. Drenos (Fotios); Cook, J.P. (James P.); P. Auer (Paul); A.Y. Chu (Audrey); Giri, A. (Ayush); Zhao, W. (Wei); M. Jakobsdottir (Margret); Lin, L.-A. (Li-An); J.M. Stafford (Jeanette M.); N. Amin (Najaf); Mei, H. (Hao); J. Yao (Jiefen); J.M. Voorman (Jeanine); M.G. Larson (Martin); M.L. Grove (Megan); A.V. Smith (Albert Vernon); S.J. Hwang; H. Chen (Han); T. Huan (Tianxiao); Kosova, G. (Gulum); N.O. Stitziel (Nathan); S. Kathiresan (Sekar); N.J. Samani (Nilesh); H. Schunkert (Heribert); P. Deloukas (Panagiotis); M. Li (Man); C. Fuchsberger (Christian); C. Pattaro (Cristian); M. Gorski (Mathias); C. Kooperberg (Charles); G. Papanicolaou (George); Rossouw, J.E. (Jacques E.); J.D. Faul (Jessica D.); S.L.R. Kardia (Sharon); C. Bouchard (Claude); L.J. Raffel (Leslie); Uitterlinden, A.G. (André G.); O.H. Franco (Oscar); R. Vasan (Ramachandran); C.J. O'Donnell (Christopher); K.D. Taylor (Kent); K.Y. Liu; E.P. Bottinger (Erwin); R.F. Gottesman (Rebecca); E.W. Daw (E. Warwick); F. Giulianini (Franco); S.K. Ganesh (Santhi); E. Salfati (Elias); T.B. Harris (Tamara); Launer, L.J. (Lenore J.); M. Dörr (Marcus); S.B. Felix (Stephan); R. Rettig (Rainer); H. Völzke (Henry); E. Kim (Eric); W.-J. Lee (Wen-Jane); I.T. Lee; Sheu, W.H.-H. (Wayne H.-H.); Tsosie, K.S. (Krystal S.); Edwards, D.R.V. (Digna R. Velez); Y. Liu (YongMei); Correa, A. (Adolfo); D.R. Weir (David); U. Völker (Uwe); P.M. Ridker (Paul); E.A. Boerwinkle (Eric); V. Gudnason (Vilmundur); A. Reiner (Alexander); Van Duijn, C.M. (Cornelia M.); I.B. Borecki (Ingrid); T.L. Edwards (Todd L.); A. Chakravarti (Aravinda); Rotter, J.I. (Jerome I.); B.M. Psaty (Bruce); R.J.F. Loos (Ruth); M. Fornage (Myriam); G.B. Ehret (Georg); C. Newton-Cheh (Christopher); D. Levy (Daniel); D.I. Chasman (Daniel)

    2016-01-01

    textabstractMeta-analyses of association results for blood pressure using exome-centric single-variant and gene-based tests identified 31 new loci in a discovery stage among 146,562 individuals, with follow-up and meta-analysis in 180,726 additional individuals (total n = 327,288). These blood

  9. Comparative clinical effectiveness of management strategies for sciatica: systematic review and network meta-analyses.

    Science.gov (United States)

    Lewis, Ruth A; Williams, Nefyn H; Sutton, Alex J; Burton, Kim; Din, Nafees Ud; Matar, Hosam E; Hendry, Maggie; Phillips, Ceri J; Nafees, Sadia; Fitzsimmons, Deborah; Rickard, Ian; Wilkinson, Clare

    2015-06-01

    There are numerous treatment approaches for sciatica. Previous systematic reviews have not compared all these strategies together. To compare the clinical effectiveness of different treatment strategies for sciatica simultaneously. Systematic review and network meta-analysis. We searched 28 electronic databases and online trial registries, along with bibliographies of previous reviews for comparative studies evaluating any intervention to treat sciatica in adults, with outcome data on global effect or pain intensity. Network meta-analysis methods were used to simultaneously compare all treatment strategies and allow indirect comparisons of treatments between studies. The study was funded by the UK National Institute for Health Research Health Technology Assessment program; there are no potential conflict of interests. We identified 122 relevant studies; 90 were randomized controlled trials (RCTs) or quasi-RCTs. Interventions were grouped into 21 treatment strategies. Internal and external validity of included studies was very low. For overall recovery as the outcome, compared with inactive control or conventional care, there was a statistically significant improvement following disc surgery, epidural injections, nonopioid analgesia, manipulation, and acupuncture. Traction, percutaneous discectomy, and exercise therapy were significantly inferior to epidural injections or surgery. For pain as the outcome, epidural injections and biological agents were significantly better than inactive control, but similar findings for disc surgery were not statistically significant. Biological agents were significantly better for pain reduction than bed rest, nonopioids, and opioids. Opioids, education/advice alone, bed rest, and percutaneous discectomy were inferior to most other treatment strategies; although these findings represented large effects, they were statistically equivocal. For the first time, many different treatment strategies for sciatica have been compared in the

  10. The effects of clinical and statistical heterogeneity on the predictive values of results from meta-analyses

    NARCIS (Netherlands)

    Melsen, W G; Rovers, M M; Bonten, M J M; Bootsma, M C J|info:eu-repo/dai/nl/304830305

    Variance between studies in a meta-analysis will exist. This heterogeneity may be of clinical, methodological or statistical origin. The last of these is quantified by the I(2) -statistic. We investigated, using simulated studies, the accuracy of I(2) in the assessment of heterogeneity and the

  11. Suicidality and aggression during antidepressant treatment: systematic review and meta-analyses based on clinical study reports.

    Science.gov (United States)

    Sharma, Tarang; Guski, Louise Schow; Freund, Nanna; Gøtzsche, Peter C

    2016-01-27

    To study serious harms associated with selective serotonin and serotonin-norepinephrine reuptake inhibitors.Design Systematic review and meta-analysis. Mortality and suicidality. Secondary outcomes were aggressive behaviour and akathisia. Clinical study reports for duloxetine, fluoxetine, paroxetine, sertraline, and venlafaxine obtained from the European and UK drug regulators, and summary trial reports for duloxetine and fluoxetine from Eli Lilly's website. Double blind placebo controlled trials that contained any patient narratives or individual patient listings of harms. Two researchers extracted data independently; the outcomes were meta-analysed by Peto's exact method (fixed effect model). We included 70 trials (64,381 pages of clinical study reports) with 18,526 patients. These trials had limitations in the study design and discrepancies in reporting, which may have led to serious under-reporting of harms. For example, some outcomes appeared only in individual patient listings in appendices, which we had for only 32 trials, and we did not have case report forms for any of the trials. Differences in mortality (all deaths were in adults, odds ratio 1.28, 95% confidence interval 0.40 to 4.06), suicidality (1.21, 0.84 to 1.74), and akathisia (2.04, 0.93 to 4.48) were not significant, whereas patients taking antidepressants displayed more aggressive behaviour (1.93, 1.26 to 2.95). For adults, the odds ratios were 0.81 (0.51 to 1.28) for suicidality, 1.09 (0.55 to 2.14) for aggression, and 2.00 (0.79 to 5.04) for akathisia. The corresponding values for children and adolescents were 2.39 (1.31 to 4.33), 2.79 (1.62 to 4.81), and 2.15 (0.48 to 9.65). In the summary trial reports on Eli Lilly's website, almost all deaths were noted, but all suicidal ideation events were missing, and the information on the remaining outcomes was incomplete. Because of the shortcomings identified and having only partial access to appendices with no access to case report forms, the harms

  12. Airway management education: simulation based training versus non-simulation based training-A systematic review and meta-analyses.

    Science.gov (United States)

    Sun, Yanxia; Pan, Chuxiong; Li, Tianzuo; Gan, Tong J

    2017-02-01

    Simulation-based training (SBT) has become a standard for medical education. However, the efficacy of simulation based training in airway management education remains unclear. The aim of this study was to evaluate all published evidence comparing the effectiveness of SBT for airway management versus non-simulation based training (NSBT) on learner and patient outcomes. Systematic review with meta-analyses were used. Data were derived from PubMed, EMBASE, CINAHL, Scopus, the Cochrane Controlled Trials Register and Cochrane Database of Systematic Reviews from inception to May 2016. Published comparative trials that evaluated the effect of SBT on airway management training in compared with NSBT were considered. The effect sizes with 95% confidence intervals (CI) were calculated for outcomes measures. Seventeen eligible studies were included. SBT was associated with improved behavior performance [standardized mean difference (SMD):0.30, 95% CI: 0.06 to 0.54] in comparison with NSBT. However, the benefits of SBT were not seen in time-skill (SMD:-0.13, 95% CI: -0.82 to 0.52), written examination score (SMD: 0.39, 95% CI: -0.09 to 0.86) and success rate of procedure completion on patients [relative risk (RR): 1.26, 95% CI: 0.96 to 1.66]. SBT may be not superior to NSBT on airway management training.

  13. Diagnostic accuracy of dual-energy computed tomography in patients with gout: A meta-analysis.

    Science.gov (United States)

    Lee, Young Ho; Song, Gwan Gyu

    2017-08-01

    This study aimed to evaluate the diagnostic performance of dual-energy computed tomography (DECT) for patients with gout. We searched the Medline, Embase, and Cochrane Library databases, and performed a meta-analysis on the diagnostic accuracy of DECT in patients with gout. A total of eight studies including 510 patients with gout and 268 controls (patients with non-gout inflammatory arthritis) were available for the meta-analysis. The pooled sensitivity and specificity of DECT were 84.7% (95% confidence interval [CI]: 81.3-87.7) and 93.7% (93.0-96.3), respectively. The positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 9.882 (6.122-15.95), 0.163 (0.097-0.272), and 78.10 (31.14-195.84), respectively. The area under the curve of DECT was 0.956 and the Q * index was 0.889, indicating a high diagnostic accuracy. Some between-study heterogeneity was found in the meta-analyses. However, there was no evidence of a threshold effect (Spearman correlation coefficient = 0.419; p = 0.035). In addition, meta-regression showed that the sample size, study design, and diagnostic criteria were not sources of heterogeneity, and subgroup meta-analyses did not change the overall diagnostic accuracy. Our meta-analysis of published studies demonstrates that DECT has a high diagnostic accuracy and plays an important role in the diagnosis of gout. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Riparian plant community responses to increased flooding: a meta-analysis.

    Science.gov (United States)

    Garssen, Annemarie G; Baattrup-Pedersen, Annette; Voesenek, Laurentius A C J; Verhoeven, Jos T A; Soons, Merel B

    2015-08-01

    A future higher risk of severe flooding of streams and rivers has been projected to change riparian plant community composition and species richness, but the extent and direction of the expected change remain uncertain. We conducted a meta-analysis to synthesize globally available experimental evidence and assess the effects of increased flooding on (1) riparian adult plant and seedling survival, (2) riparian plant biomass and (3) riparian plant species composition and richness. We evaluated which plant traits are of key importance for the response of riparian plant species to flooding. We identified and analysed 53 papers from ISI Web of Knowledge which presented quantitative experimental results on flooding treatments and corresponding control situations. Our meta-analysis demonstrated how longer duration of flooding, greater depth of flooding and, particularly, their combination reduce seedling survival of most riparian species. Plant height above water level, ability to elongate shoots and plasticity in root porosity were decisive for adult plant survival and growth during longer periods of flooding. Both 'quiescence' and 'escape' proved to be successful strategies promoting riparian plant survival, which was reflected in the wide variation in survival (full range between 0 and 100%) under fully submerged conditions, while plants that protrude above the water level (>20 cm) almost all survive. Our survey confirmed that the projected increase in the duration and depth of flooding periods is sufficient to result in species shifts. These shifts may lead to increased or decreased riparian species richness depending on the nutrient, climatic and hydrological status of the catchment. Species richness was generally reduced at flooded sites in nutrient-rich catchments and sites that previously experienced relatively stable hydrographs (e.g. rain-fed lowland streams). Species richness usually increased at sites in desert and semi-arid climate regions (e.g. intermittent

  15. Occupational trichloroethylene exposure and kidney cancer risk: a meta-analysis

    NARCIS (Netherlands)

    Karami, S.; Lan, Q.; Rothman, N.; Stewart, P.A.; Lee, K.M.; Vermeulen, R.|info:eu-repo/dai/nl/216532620; Moore, L.E.

    2012-01-01

    OBJECTIVES: Inconsistent epidemiological findings, debate over interpretation, and extrapolation of findings from animal studies to humans have produced uncertainty surrounding the carcinogenicity of trichloroethylene (TCE) exposure in occupational settings. We updated meta-analyses of published

  16. Diverging Conclusions from the Same Meta-Analysis in Drug Safety: Source of Data (Primary Versus Secondary) Takes a Toll.

    Science.gov (United States)

    Prada-Ramallal, Guillermo; Takkouche, Bahi; Figueiras, Adolfo

    2017-04-01

    Meta-analyses of observational studies represent an important tool for assessing efficacy and safety in the pharmacoepidemiologic field. The data from the individual studies are either primary (i.e., collected through interviews or self-administered questionnaires) or secondary (i.e., collected from databases that were established for other purposes). So far, the origin of the data (primary vs. secondary) has not been systematically assessed as a source of heterogeneity in pharmacoepidemiologic meta-analyses. The aim was to assess the impact of considering the source of exposure data as a criterion in sensitivity and subgroup analysis on the conclusions of drug safety meta-analyses. We selected meta-analyses published between 2013 and 2015 in which the intake of frequently used over-the-counter medicines was either the main exposure or a concomitant treatment and the outcome had short latency and induction periods. We stratified the results by origin of data (primary vs. secondary) and compared the new results to those presented originally in the meta-analyses. We used four meta-analyses that fulfilled our criteria of inclusion. The results were selective serotonin reuptake inhibitors and upper gastrointestinal bleeding: original estimate odds ratio (OR) = 1.71 [95% confidence interval (CI) 1.44-2.04], OR primary data = 1.19 (95% CI 0.90-1.58), OR secondary data = 1.81 (95% CI 1.50-2.17); proton pump inhibitors and cardiac events: original estimate hazard ratio (HR) = 1.35 (95% CI 1.18-1.54), HR primary data = 1.05 (95% CI 0.87-1.26), HR secondary data = 1.43 (95% CI 1.23-1.66); non-aspirin non-steroidal anti-inflammatory drugs and myocardial infarction: original estimate risk ratio (RR) = 1.08 (95% CI 0.95-1.22), RR primary data = 0.57 (95% CI 0.34-0.96), RR secondary data = 1.15 (95% CI 1.03-1.28); paracetamol during pregnancy and childhood asthma: original estimate OR = 1.32 (95% CI 1.14-1.52), OR primary data = 1.23 (95% CI 1.06-1.42), OR

  17. Interpreting trial results following use of different intention-to-treat approaches for preventing attrition bias: a meta-epidemiological study protocol.

    Science.gov (United States)

    Dossing, Anna; Tarp, Simon; Furst, Daniel E; Gluud, Christian; Beyene, Joseph; Hansen, Bjarke B; Bliddal, Henning; Christensen, Robin

    2014-09-26

    When participants drop out of randomised clinical trials, as frequently happens, the intention-to-treat (ITT) principle does not apply, potentially leading to attrition bias. Data lost from patient dropout/lack of follow-up are statistically addressed by imputing, a procedure prone to bias. Deviations from the original definition of ITT are referred to as modified intention-to-treat (mITT). As yet, the impact of the potential bias associated with mITT has not been assessed. Our objective is to investigate potential bias and disadvantages of performing mITT and evaluate possible concerns when executing different mITT approaches in meta-analyses. Using meta-epidemiology on randomised trials considered less prone to bias (ie, good internal validity) and assessing biological or targeted agents in patients with rheumatoid arthritis, we will meta-analyse data from 10 biological and targeted drugs based on collections of trials that would correspond to 10 individual meta-analyses. This study will enhance transparency for evaluating mITT treatment effects described in meta-analyses. The intended audience will include healthcare researchers, policymakers and clinicians. Results of the study will be disseminated by peer-review publication. In PROSPERO CRD42013006702, 11. December 2013. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. Auto-titrating versus fixed continuous positive airway pressure for the treatment of obstructive sleep apnea: a systematic review with meta-analyses

    Directory of Open Access Journals (Sweden)

    Ip Stanley

    2012-03-01

    Full Text Available Abstract Background Obstructive sleep apnea is a relatively common disorder that can lead to lost productivity and cardiovascular disease. The form of positive airway treatment that should be offered is unclear. Methods MEDLINE and the Cochrane Central Trials registry were searched for English language randomized controlled trials comparing auto-titrating positive airway pressure (APAP with continuous positive airway pressure (CPAP in adults with obstructive sleep apnea (inception through 9/2010. Six researchers extracted information on study design, potential bias, patient characteristics, interventions and outcomes. Data for each study were extracted by one reviewer and confirmed by another. Random effects model meta-analyses were performed for selected outcomes. Results Twenty-four randomized controlled trials met the inclusion criteria. In individual studies, APAP and fixed CPAP resulted in similar changes from baseline in the apnea-hypopnea index, most other sleep study measures and quality of life. By meta-analysis, APAP improved compliance by 11 minutes per night (95% CI, 3 to 19 minutes and reduced sleepiness as measured by the Epworth Sleepiness Scale by 0.5 points (95% CI, 0.8 to 0.2 point reduction compared with fixed CPAP. Fixed CPAP improved minimum oxygen saturation by 1.3% more than APAP (95% CI, 0.4 to 2.2%. Studies had relatively short follow-up and generally excluded patients with significant comorbidities. No study reported on objective clinical outcomes. Conclusions Statistically significant differences were found but clinical importance is unclear. Because the treatment effects are similar between APAP and CPAP, the therapy of choice may depend on other factors such as patient preference, specific reasons for non-compliance and cost.

  19. Parental experiences of providing skin-to-skin care to their newborn infant--part 2: a qualitative meta-synthesis.

    Science.gov (United States)

    Anderzén-Carlsson, Agneta; Lamy, Zeni C; Tingvall, Maria; Eriksson, Mats

    2014-01-01

    To synthesize and interpret qualitative research findings focusing on parental experiences of skin-to-skin care (SSC) for newborn infants. SSC induces many benefits for newborn infants and their parents. Three meta-analyses have been conducted on physiological outcomes, but no previous qualitative meta-synthesis on parental experiences of SSC has been identified. The present meta-synthesis was guided by the methodology described by Paterson and co-workers. Four databases were searched, without year or language limitations, up until December 2013. Manual searches were also performed. The searches and subsequent quality appraisal resulted in the inclusion of 29 original qualitative papers from 9 countries, reporting experiences from 401 mothers and 94 fathers. The meta-synthesis entails a meta-data analysis, analysis of meta-method, and meta-theory in the included primary studies. Based on the three analyses, the meta-synthesis represents a new interpretation of a phenomenon. The results of the meta-data analysis have been presented as a qualitative systematic review in a separate paper. When synthesizing and interpreting the findings from the included analyses, a theoretical model of Becoming a parent under unfamiliar circumstances emerged. Providing SSC seems to be a restorative as well as an energy-draining experience. A supportive environment has been described as facilitating the restorative experience, whereas obstacles in the environment seem to make the provision of SSC energy-draining for parents. When the process is experienced as positive, it facilitates the growth of parental self-esteem and makes the parents ready to assume full responsibility for their child. The results show that SSC can be interpreted not only as a family-including and important health care intervention but also in terms of actually becoming a parent. The process of becoming a parent in this specific situation is influenced by external factors in three different levels; family and

  20. Post-partum depressive symptoms and medically assisted conception: a systematic review and meta-analysis.

    Science.gov (United States)

    Gressier, F; Letranchant, A; Cazas, O; Sutter-Dallay, A L; Falissard, B; Hardy, P

    2015-11-01

    Does medically assisted conception increase the risk of post-partum depressive symptoms? Our literature review and meta-analysis showed no increased risk of post-partum depressive symptoms in women after medically assisted conception. Women who conceive with medically assisted conception, which can be considered as a stressful life event, could face an increased risk of depressive symptoms. However, no previous meta-analysis has been performed on the association between medically assisted conception and post-partum depressive symptoms. A systematic review with electronic searches of PubMed, ISI Web of Knowledge and PsycINFO databases up to December 2014 was conducted to identify articles evaluating post-partum depressive symptoms in women who had benefited from medically assisted conception compared with those with a spontaneous pregnancy. Meta-analyses were also performed on clinically significant post-partum depressive symptoms according to PRISMA guidelines. From 569 references, 492 were excluded on title, 42 on abstract and 17 others on full-text. Therefore, 18 studies were included in the review and 8 in the meta-analysis (2451 women) on clinically significant post-partum depressive symptoms after medically assisted conception compared with a spontaneous pregnancy. A sensitivity meta-analysis on assisted reproductive technologies and spontaneous pregnancy (6 studies, 1773 women) was also performed. The quality of the studies included in the meta-analyses was evaluated using the Strengthening the Reporting of Observational Studies in Epidemiology Statement for observational research. The data were pooled using RevMan software by the Cochrane Collaboration. Heterogeneity between studies was assessed from the results of the χ(2) and I(2) statistics. Biases were assessed with funnel plots and Egger's test. A fixed effects model was used for the meta-analyses because of the low level of heterogeneity between the studies. The systematic review of studies examining

  1. STRUKTUR META TEORI AKUNTANSI KEUANGAN (Sebuah Telaah dan Perbandingan antara FASB dan IASC

    Directory of Open Access Journals (Sweden)

    I Made Narsa

    2007-01-01

    Full Text Available The objectives of this paper is to analyses the structure of meta-theoretical of financial accounting that was used by FASB and IASC to develop the conceptual framework for financial accounting reporting. The discussion of conceptual framework conducted by comparison of the basic different between the FASB and IASC framework, then analyses the constraints to implement IFRS and identify the way out of the constraints faced by the body. Abstract in Bahasa Indonesia : Penelitian ini bertujuan untuk membahas struktur meta teori yang dipergunakan oleh FASB dan IASC dalam mengembangkan rerangka konseptual, menelaah perbedaan-perbedaan mendasar, menganalisis hambatan-hambatan yang dialami serta mengidentifikasi upaya-upaya yang harus dilakukan agar IFRS diterapkan oleh negara-negara anggota. Penelitian ini dilakukan dengan cara membandingkan rerangka dasar yang diatur dalam FASB dan IASC dan kemudian menganalisa hambatan yang timbul dengan adanya penerapan IFRS dan mengidentifikasi bagaimana hambatan tersebut dapat diselesaikan. Kata kunci: globalisasi, harmonisasi, meta teori, FASB dan IASC, kerangka dasar, akuntansi keuangan

  2. Diagnostic accuracy of serological diagnosis of hepatitis C and B using dried blood spot samples (DBS): two systematic reviews and meta-analyses.

    Science.gov (United States)

    Lange, Berit; Cohn, Jennifer; Roberts, Teri; Camp, Johannes; Chauffour, Jeanne; Gummadi, Nina; Ishizaki, Azumi; Nagarathnam, Anupriya; Tuaillon, Edouard; van de Perre, Philippe; Pichler, Christine; Easterbrook, Philippa; Denkinger, Claudia M

    2017-11-01

    Dried blood spots (DBS) are a convenient tool to enable diagnostic testing for viral diseases due to transport, handling and logistical advantages over conventional venous blood sampling. A better understanding of the performance of serological testing for hepatitis C (HCV) and hepatitis B virus (HBV) from DBS is important to enable more widespread use of this sampling approach in resource limited settings, and to inform the 2017 World Health Organization (WHO) guidance on testing for HBV/HCV. We conducted two systematic reviews and meta-analyses on the diagnostic accuracy of HCV antibody (HCV-Ab) and HBV surface antigen (HBsAg) from DBS samples compared to venous blood samples. MEDLINE, EMBASE, Global Health and Cochrane library were searched for studies that assessed diagnostic accuracy with DBS and agreement between DBS and venous sampling. Heterogeneity of results was assessed and where possible a pooled analysis of sensitivity and specificity was performed using a bivariate analysis with maximum likelihood estimate and 95% confidence intervals (95%CI). We conducted a narrative review on the impact of varying storage conditions or limits of detection in subsets of samples. The QUADAS-2 tool was used to assess risk of bias. For the diagnostic accuracy of HBsAg from DBS compared to venous blood, 19 studies were included in a quantitative meta-analysis, and 23 in a narrative review. Pooled sensitivity and specificity were 98% (95%CI:95%-99%) and 100% (95%CI:99-100%), respectively. For the diagnostic accuracy of HCV-Ab from DBS, 19 studies were included in a pooled quantitative meta-analysis, and 23 studies were included in a narrative review. Pooled estimates of sensitivity and specificity were 98% (CI95%:95-99) and 99% (CI95%:98-100), respectively. Overall quality of studies and heterogeneity were rated as moderate in both systematic reviews. HCV-Ab and HBsAg testing using DBS compared to venous blood sampling was associated with excellent diagnostic accuracy

  3. The Retina in Multiple System Atrophy: Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Carlos E. Mendoza-Santiesteban

    2017-05-01

    Full Text Available BackgroundMultiple system atrophy (MSA is a rare, adult-onset, rapidly progressive fatal synucleinopathy that primarily affects oligodendroglial cells in the brain. Patients with MSA only rarely have visual complaints, but recent studies of the retina using optical coherence tomography (OCT showed atrophy of the peripapillary retinal nerve fiber layer (RNFL and to a lesser extent the macular ganglion cell layer (GCL complex.MethodsWe performed a literature review and meta-analysis according to the preferred reporting items for systematic reviews and meta-analyses guidelines for studies published before January 2017, identified through PubMed and Google Scholar databases, which reported OCT-related outcomes in patients with MSA and controls. A random-effects model was constructed.ResultsThe meta-analysis search strategy yielded 15 articles of which 7 met the inclusion criteria. The pooled difference in the average thickness of the RNFL was −5.48 μm (95% CI, −6.23 to −4.73; p < 0.0001, indicating significant thinning in patients with MSA. The pooled results showed significant thinning in all the specific RNFL quadrants, except in the temporal RNFL quadrant, where the thickness in MSA and controls was similar [pooled difference of 1.11 µm (95% CI, −4.03 to 6.26; p = 0.67]. This pattern of retinal damage suggests that MSA patients have preferential loss of retinal ganglion cells projecting to the magnocellular pathway (M-cells, which are mainly located in the peripheral retina and are not essential for visual acuity. Visual acuity, on the other hand, relies mostly on macular ganglion cells projecting to the parvocellular pathway (P-cells through the temporal portion of the RNFL, which are relatively spared in MSA patients.ConclusionThe retinal damage in patients with MSA differs from that observed in patients with Parkinson disease (PD. Patients with MSA have more relative preservation of temporal sector of the RNFL and less

  4. Testing for Questionable Research Practices in a Meta-Analysis: An Example from Experimental Parapsychology.

    Directory of Open Access Journals (Sweden)

    Dick J Bierman

    Full Text Available We describe a method of quantifying the effect of Questionable Research Practices (QRPs on the results of meta-analyses. As an example we simulated a meta-analysis of a controversial telepathy protocol to assess the extent to which these experimental results could be explained by QRPs. Our simulations used the same numbers of studies and trials as the original meta-analysis and the frequencies with which various QRPs were applied in the simulated experiments were based on surveys of experimental psychologists. Results of both the meta-analysis and simulations were characterized by 4 metrics, two describing the trial and mean experiment hit rates (HR of around 31%, where 25% is expected by chance, one the correlation between sample-size and hit-rate, and one the complete P-value distribution of the database. A genetic algorithm optimized the parameters describing the QRPs, and the fitness of the simulated meta-analysis was defined as the sum of the squares of Z-scores for the 4 metrics. Assuming no anomalous effect a good fit to the empirical meta-analysis was found only by using QRPs with unrealistic parameter-values. Restricting the parameter space to ranges observed in studies of QRP occurrence, under the untested assumption that parapsychologists use comparable QRPs, the fit to the published Ganzfeld meta-analysis with no anomalous effect was poor. We allowed for a real anomalous effect, be it unidentified QRPs or a paranormal effect, where the HR ranged from 25% (chance to 31%. With an anomalous HR of 27% the fitness became F = 1.8 (p = 0.47 where F = 0 is a perfect fit. We conclude that the very significant probability cited by the Ganzfeld meta-analysis is likely inflated by QRPs, though results are still significant (p = 0.003 with QRPs. Our study demonstrates that quantitative simulations of QRPs can assess their impact. Since meta-analyses in general might be polluted by QRPs, this method has wide applicability outside the domain of

  5. Testing for Questionable Research Practices in a Meta-Analysis: An Example from Experimental Parapsychology.

    Science.gov (United States)

    Bierman, Dick J; Spottiswoode, James P; Bijl, Aron

    2016-01-01

    We describe a method of quantifying the effect of Questionable Research Practices (QRPs) on the results of meta-analyses. As an example we simulated a meta-analysis of a controversial telepathy protocol to assess the extent to which these experimental results could be explained by QRPs. Our simulations used the same numbers of studies and trials as the original meta-analysis and the frequencies with which various QRPs were applied in the simulated experiments were based on surveys of experimental psychologists. Results of both the meta-analysis and simulations were characterized by 4 metrics, two describing the trial and mean experiment hit rates (HR) of around 31%, where 25% is expected by chance, one the correlation between sample-size and hit-rate, and one the complete P-value distribution of the database. A genetic algorithm optimized the parameters describing the QRPs, and the fitness of the simulated meta-analysis was defined as the sum of the squares of Z-scores for the 4 metrics. Assuming no anomalous effect a good fit to the empirical meta-analysis was found only by using QRPs with unrealistic parameter-values. Restricting the parameter space to ranges observed in studies of QRP occurrence, under the untested assumption that parapsychologists use comparable QRPs, the fit to the published Ganzfeld meta-analysis with no anomalous effect was poor. We allowed for a real anomalous effect, be it unidentified QRPs or a paranormal effect, where the HR ranged from 25% (chance) to 31%. With an anomalous HR of 27% the fitness became F = 1.8 (p = 0.47 where F = 0 is a perfect fit). We conclude that the very significant probability cited by the Ganzfeld meta-analysis is likely inflated by QRPs, though results are still significant (p = 0.003) with QRPs. Our study demonstrates that quantitative simulations of QRPs can assess their impact. Since meta-analyses in general might be polluted by QRPs, this method has wide applicability outside the domain of experimental

  6. An improved method for bivariate meta-analysis when within-study correlations are unknown.

    Science.gov (United States)

    Hong, Chuan; D Riley, Richard; Chen, Yong

    2018-03-01

    Multivariate meta-analysis, which jointly analyzes multiple and possibly correlated outcomes in a single analysis, is becoming increasingly popular in recent years. An attractive feature of the multivariate meta-analysis is its ability to account for the dependence between multiple estimates from the same study. However, standard inference procedures for multivariate meta-analysis require the knowledge of within-study correlations, which are usually unavailable. This limits standard inference approaches in practice. Riley et al proposed a working model and an overall synthesis correlation parameter to account for the marginal correlation between outcomes, where the only data needed are those required for a separate univariate random-effects meta-analysis. As within-study correlations are not required, the Riley method is applicable to a wide variety of evidence synthesis situations. However, the standard variance estimator of the Riley method is not entirely correct under many important settings. As a consequence, the coverage of a function of pooled estimates may not reach the nominal level even when the number of studies in the multivariate meta-analysis is large. In this paper, we improve the Riley method by proposing a robust variance estimator, which is asymptotically correct even when the model is misspecified (ie, when the likelihood function is incorrect). Simulation studies of a bivariate meta-analysis, in a variety of settings, show a function of pooled estimates has improved performance when using the proposed robust variance estimator. In terms of individual pooled estimates themselves, the standard variance estimator and robust variance estimator give similar results to the original method, with appropriate coverage. The proposed robust variance estimator performs well when the number of studies is relatively large. Therefore, we recommend the use of the robust method for meta-analyses with a relatively large number of studies (eg, m≥50). When the

  7. Bleeding and pneumonia in intensive care patients given ranitidine and sucralfate for prevention of stress ulcer: meta-analysis of randomised controlled trials

    Science.gov (United States)

    Messori, A; Trippoli, S; Vaiani, M; Gorini, M; Corrado, A

    2000-01-01

    Objectives To determine the effectiveness of ranitidine and sucralfate in the prevention of stress ulcer in critical patients and to assess if these treatments affect the risk of nosocomial pneumonia. Design Published studies retrieved through Medline and other databases. Five meta-analyses evaluated effectiveness in terms of bleeding rates (A: ranitidine v placebo; B: sucralfate v placebo) and infectious complications in terms of incidence of nosocomial pneumonia (C: ranitidine v placebo; D: sucralfate v placebo; E: ranitidine v sucralfate). Trial quality was determined with an empirical ad hoc procedure. Main outcome measures Rates of clinically important gastrointestinal bleeding and nosocomial pneumonia (compared between the two study arms and expressed with odds ratios specific for individual studies and meta-analytic summary odds ratios). Results Meta-analysis A (five studies) comprised 398 patients; meta-analysis C (three studies) comprised 311 patients; meta-analysis D (two studies) comprised 226 patients: and meta-analysis E (eight studies) comprised 1825 patients. Meta-analysis B was not carried out as the literature search selected only one clinical trial. In meta-analysis A ranitidine was found to have the same effectiveness as placebo (odds ratio of bleeding 0.72, 95% confidence interval 0.30 to 1.70, P=0.46). In placebo controlled studies (meta-analyses C and D) ranitidine and sucralfate had no influence on the incidence of nosocomial pneumonia. In comparison with sucralfate, ranitidine significantly increased the incidence of nosocomial pneumonia (meta-analysis E: 1.35, 1.07 to 1.70, P=0.012). The mean quality score in the four analyses (on a 0 to 10 scale) ranged from 5.6 in meta-analysis E to 6.6 in meta-analysis A. Conclusions Ranitidine is ineffective in the prevention of gastrointestinal bleeding in patients in intensive care and might increase the risk of pneumonia. Studies on sucralfate do not provide conclusive results. These findings are

  8. Consequences of new product development speed : a meta-analysis

    NARCIS (Netherlands)

    Cankurtaran, P.; Langerak, F.; Griffin, A.

    2013-01-01

    Five meta-analyses previously have been published on the topic of new product development involving the concept of new product development speed. Three of these studies have investigated antecedents to new product development success, of which just one was new product development speed. The other

  9. Meta-analysis constrained by data: Recommendations to improve relevance of nutrient management research

    Science.gov (United States)

    Five research teams received funding through the North American 4R Research Fund to conduct meta-analyses of the air and water quality impacts of on-farm 4R nutrient management practices. In compiling or expanding databases for these analyses on environmental and crop production effects, researchers...

  10. Why Do Rape Survivors Volunteer for Face-to-Face Interviews? A Meta-Study of Victims' Reasons for and Concerns about Research Participation

    Science.gov (United States)

    Campbell, Rebecca; Adams, Adrienne E.

    2009-01-01

    There is growing interest in understanding how different research methods are perceived by victims of violence and what survivors will reveal to researchers (termed "meta-research" or "meta-studies"). The purpose of this project was to conduct a qualitative meta-study on why rape survivors chose to participate in community-based, face-to-face…

  11. Anion Binding by Meta Ureido-substituted Thiacalix[4]arenes

    Czech Academy of Sciences Publication Activity Database

    Kundrát, O.; Eigner, V.; Cuřínová, Petra; Kroupa, J.; Lhoták, P.

    2011-01-01

    Roč. 67, č. 43 (2011), s. 8367-8372 ISSN 0040-4020 R&D Projects: GA ČR GA203/09/0691; GA AV ČR IAAX08240901 Institutional support: RVO:67985858 Keywords : calixarene * meta nitration * recognition Subject RIV: CC - Organic Chemistry Impact factor: 3.025, year: 2011

  12. Exploring reasons for the observed inconsistent trial reports on intra-articular injections with hyaluronic acid in the treatment of osteoarthritis: Meta-regression analyses of randomized trials.

    Science.gov (United States)

    Johansen, Mette; Bahrt, Henriette; Altman, Roy D; Bartels, Else M; Juhl, Carsten B; Bliddal, Henning; Lund, Hans; Christensen, Robin

    2016-08-01

    The aim was to identify factors explaining inconsistent observations concerning the efficacy of intra-articular hyaluronic acid compared to intra-articular sham/control, or non-intervention control, in patients with symptomatic osteoarthritis, based on randomized clinical trials (RCTs). A systematic review and meta-regression analyses of available randomized trials were conducted. The outcome, pain, was assessed according to a pre-specified hierarchy of potentially available outcomes. Hedges׳s standardized mean difference [SMD (95% CI)] served as effect size. REstricted Maximum Likelihood (REML) mixed-effects models were used to combine study results, and heterogeneity was calculated and interpreted as Tau-squared and I-squared, respectively. Overall, 99 studies (14,804 patients) met the inclusion criteria: Of these, only 71 studies (72%), including 85 comparisons (11,216 patients), had adequate data available for inclusion in the primary meta-analysis. Overall, compared with placebo, intra-articular hyaluronic acid reduced pain with an effect size of -0.39 [-0.47 to -0.31; P hyaluronic acid. Based on available trial data, intra-articular hyaluronic acid showed a better effect than intra-articular saline on pain reduction in osteoarthritis. Publication bias and the risk of selective outcome reporting suggest only small clinical effect compared to saline. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Handedness, language lateralisation and anatomical asymmetry in schizophrenia - Meta-analysis

    NARCIS (Netherlands)

    Sommer, [No Value; Aleman, A; Ramsey, N; Bouma, A; Kahn, R

    Background Cerebral lateralisation appears to be decreased in schizophrenia. Results of studies investigating this. however, are equivocal. Aims To review quantitatively the literature on decreased lateralisation in schizophrenia. Method Meta-analyses were conducted on 19 studies on handedness. 10

  14. Meta-analysis of organizational skills interventions for children and adolescents with Attention-Deficit/Hyperactivity Disorder

    DEFF Research Database (Denmark)

    Bikic, Aida; Reichow, Brian; A. McCauley, Spencer

    2017-01-01

    Abstract Background: In addition to problems with attention and hyperactivity, children with ADHD present with poor organizational skills required for managing time and materials in academic projects. Organizational skills training (OST) has been increasingly used to address these deficits. We...... conducted a systematic review and meta-analysis of OST in children with ADHD. Objectives: The objective of this study was to systematically review the evidence of the effects of OST for children with ADHD for organizational skills, attention, and academic performance. Methods: We searched 3 electronic......-analyses across six outcomes: teacher- and parent-rated organizational skills, teacher- and parent-rated inattention, teacher-rated academic performance, and grade point average (GPA). Risk of bias was assessed for randomization, allocation concealment, blinding of participants and treatment personnel, blinding...

  15. IAEA coordinated research project (CRP) on 'Analytical and experimental benchmark analyses of accelerator driven systems'

    International Nuclear Information System (INIS)

    Abanades, Alberto; Aliberti, Gerardo; Gohar, Yousry; Talamo, Alberto; Bornos, Victor; Kiyavitskaya, Anna; Carta, Mario; Janczyszyn, Jerzy; Maiorino, Jose; Pyeon, Cheolho; Stanculescu, Alexander; Titarenko, Yury; Westmeier, Wolfram

    2008-01-01

    In December 2005, the International Atomic Energy Agency (IAEA) has started a Coordinated Research Project (CRP) on 'Analytical and Experimental Benchmark Analyses of Accelerator Driven Systems'. The overall objective of the CRP, performed within the framework of the Technical Working Group on Fast Reactors (TWGFR) of IAEA's Nuclear Energy Department, is to increase the capability of interested Member States in developing and applying advanced reactor technologies in the area of long-lived radioactive waste utilization and transmutation. The specific objective of the CRP is to improve the present understanding of the coupling of an external neutron source (e.g. spallation source) with a multiplicative sub-critical core. The participants are performing computational and experimental benchmark analyses using integrated calculation schemes and simulation methods. The CRP aims at integrating some of the planned experimental demonstration projects of the coupling between a sub-critical core and an external neutron source (e.g. YALINA Booster in Belarus, and Kyoto University's Critical Assembly (KUCA)). The objective of these experimental programs is to validate computational methods, obtain high energy nuclear data, characterize the performance of sub-critical assemblies driven by external sources, and to develop and improve techniques for sub-criticality monitoring. The paper summarizes preliminary results obtained to-date for some of the CRP benchmarks. (authors)

  16. A meta-analysis of peripheral blood nerve growth factor levels in patients with schizophrenia.

    Science.gov (United States)

    Qin, X-Y; Wu, H-T; Cao, C; Loh, Y P; Cheng, Y

    2017-09-01

    Neurotrophins particularly brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) are crucial modulators in the neurodevelopment and maintenance of central and peripheral nervous systems. Neurotrophin hypothesis of schizophrenia (SCZ) postulated that the changes in the brains of SCZ patients are the result of disturbances of developing processes involving neurotrophic factors. This hypothesis was mainly supported by the abnormal regulation of BDNF in SCZ, especially the decreased peripheral blood BDNF levels in SCZ patients validated by several meta-analyses. However, the regulation of NGF in SCZ remains unclear because of the inconsistent findings from the clinical studies. Therefore, we undertook, to the best of our knowledge, the first systematic review with a meta-analysis to quantitatively summarize the peripheral blood NGF data in SCZ patients compared with healthy control (HC) subjects. A systematic search of Pubmed, PsycINFO and Web of Science identified 13 articles encompassing a sample of 1693 individuals for the meta-analysis. Random-effects meta-analysis showed that patients with SCZ had significantly decreased peripheral blood levels of NGF when compared with the HC subjects (Hedges's g=-0.633, 95% confidence interval (CI)=-0.948 to -0.318, Pmeta-regression analyses showed that age, gender and sample size had no moderating effects on the outcome of the meta-analysis, whereas disease severity might be a confounding factor for the meta-analysis. These results demonstrated that patients with SCZ are accompanied by the decreased peripheral blood NGF levels, strengthening the clinical evidence of an abnormal neurotrophin profile in the patients with SCZ.

  17. Examining the central and peripheral processes of written word production through meta-analysis

    Directory of Open Access Journals (Sweden)

    Jeremy ePurcell

    2011-10-01

    Full Text Available Producing written words requires central cognitive processes (such as orthographic long-term and working memory as well as more peripheral processes responsible for generating the motor actions needed for producing written words in a variety of formats (handwriting, typing, etc.. In recent years, various functional neuroimaging studies have examined the neural substrates underlying the central and peripheral processes of written word production. This study provides the first quantitative meta-analysis of these studies by applying Activation Likelihood Estimation methods (Turkeltaub et al., 2002. For alphabet languages, we identified 11 studies (with a total of 17 experimental contrasts that had been designed to isolate central and/or peripheral processes of word spelling (total number of participants = 146. Three ALE meta-analyses were carried out. One involved the complete set of 17 contrasts; two others were applied to subsets of contrasts to distinguish the neural substrates of central from peripheral processes. These analyses identified a network of brain regions reliably associated with the central and peripheral processes of word spelling. Among the many significant results, is the finding that the regions with the greatest correspondence across studies were in the left inferior temporal/fusiform gyri and left inferior frontal gyrus. Furthermore, although the angular gyrus has traditionally been identified as a key site within the written word production network, none of the meta-analyses found it to be a consistent site of activation, identifying instead a region just superior/medial to the left angular gyrus in the left posterior intraparietal sulcus. In general these meta-analyses and the discussion of results provide a valuable foundation upon which future studies that examine the neural basis of written word production can build.

  18. Individual-based versus aggregate meta-analysis in multi-database studies of pregnancy outcomes

    DEFF Research Database (Denmark)

    Selmer, Randi; Haglund, Bengt; Furu, Kari

    2016-01-01

    Purpose: Compare analyses of a pooled data set on the individual level with aggregate meta-analysis in a multi-database study. Methods: We reanalysed data on 2.3 million births in a Nordic register based cohort study. We compared estimated odds ratios (OR) for the effect of selective serotonin...... covariates in the pooled data set, and 1.53 (1.19–1.96) after country-optimized adjustment. Country-specific adjusted analyses at the substance level were not possible for RVOTO. Conclusion: Results of fixed effects meta-analysis and individual-based analyses of a pooled dataset were similar in this study...... reuptake inhibitors (SSRI) and venlafaxine use in pregnancy on any cardiovascular birth defect and the rare outcome right ventricular outflow tract obstructions (RVOTO). Common covariates included maternal age, calendar year, birth order, maternal diabetes, and co-medication. Additional covariates were...

  19. A Meta-Analysis of Prosocial Media on Prosocial Behavior, Aggression, and Empathic Concern: A Multidimensional Approach

    Science.gov (United States)

    Coyne, Sarah M.; Padilla-Walker, Laura M.; Holmgren, Hailey G.; Davis, Emilie J.; Collier, Kevin M.; Memmott-Elison, Madison K.; Hawkins, Alan J.

    2018-01-01

    Studies examining the effects of exposure to prosocial media on positive outcomes are increasing in number and strength. However, existing meta-analyses use a broad definition of prosocial media that does not recognize the multidimensionality of prosocial behavior. The aim of the current study is to conduct a meta-analysis on the effects of…

  20. Executive Function and Reading Comprehension: A Meta-Analytic Review

    Science.gov (United States)

    Follmer, D. Jake

    2018-01-01

    This article presents a meta-analytic review of the relation between executive function and reading comprehension. Results (N = 6,673) supported a moderate positive association between executive function and reading comprehension (r = 0.36). Moderator analyses suggested that correlations between executive function and reading comprehension did not…

  1. Macroeconomics of natural disasters : Meta-analysis and policy options

    NARCIS (Netherlands)

    P.A.G. van Bergeijk (Peter); S. Lazzaroni (Sara)

    2013-01-01

    textabstractWe use the case of the impact of natural disasters to analyse strengths and weaknesses of meta-analysis in an emerging research field. Macroeconomists have published on this issue since 2002 (we identified 22 studies to date). The results of the studies are contradictory and

  2. Selecting Suicide Ideation Assessment Instruments: A Meta-Analytic Review

    Science.gov (United States)

    Erford, Bradley T.; Jackson, Jessica; Bardhoshi, Gerta; Duncan, Kelly; Atalay, Zumra

    2018-01-01

    Psychometric meta-analyses and reviews were provided for four commonly used suicidal ideation instruments: the Beck Scale for Suicide Ideation, the Suicide Ideation Questionnaire, the Suicide Probability Scale, and Columbia--Suicide Severity Rating Scale. Practical and technical issues and best use recommendations for screening and outcome…

  3. Meta-analyse van observationeel onderzoek ; Mogelijkheden en beperkingen bij toepassingen ten behoeve van het kwantificeren van gezondheidsrisico's

    NARCIS (Netherlands)

    Hollander AEM de; Preller EA; Heisterkamp SH; Jansen J; CCM

    1996-01-01

    In this report the applicability of meta-analysis is evaluated as a tool for quantitative review of observational (non-experimental) studies involving risk factors and health effects. These quantitative reviews are required for the assessment of the effectiveness of preventive policies that will be

  4. Occupational exposure to hexavalent chromium and cancers of the gastrointestinal tract: a meta-analysis.

    Science.gov (United States)

    Gatto, Nicole M; Kelsh, Michael A; Mai, Diem Ha; Suh, Mina; Proctor, Deborah M

    2010-08-01

    We conducted a systematic literature review and meta-analysis of oral cavity, esophageal, stomach, small intestine, colon, and rectal cancers among workers occupationally exposed to Cr(VI). Using PubMed, studies published from 1950 to 2009 evaluating the relationship between Cr(VI) exposure and GI cancers were identified. Measures of effect and variability were extracted from 32 studies meeting specific inclusion criteria, and meta-analysis summary relative risk measures were calculated using random effects models and inverse variance weighting methods. Meta-standardized mortality ratios (SMRs) were, for cancer of the: oral cavity [1.02 (95% CI=0.77-1.34)]; esophagus [1.17 (95% CI=0.90-1.51)]; stomach [1.09 (95% CI=0.93-1.28)]; colon [0.89 (95% CI=0.70-1.12)]; and rectum [1.17 (95% CI=0.98-1.39)]. Analyses of more highly exposed subgroups included in the studies or subgroups based on geographic region or by industry with recognized Cr(VI) exposures (welding, chrome plating, chromate production, and pigment production) did not result in elevated meta-SMRs except for esophageal cancer among US cohorts [meta-SMR=1.49 (95% CI=1.06-2.09)]. However, that finding was based on a subgroup of only four studies, one of which was a PMR study. Potential confounding by socioeconomic status (SES), diet and/or smoking, or limitations due to the healthy-worker effect (HWE) were evaluated, and while smoking, diet and SES may be important factors that may have upwardly biased the meta-SMRs, HWE is not likely to have significantly affected the summary results. None of three studies reporting small intestine cancers observed a statistically significant increased risk. These meta-analyses and literature review indicate that Cr(VI)-exposed workers are not at a greater risk of GI cancers than the general population.

  5. Coffee drinking and pancreatic cancer risk: a meta-analysis of cohort studies.

    Science.gov (United States)

    Dong, Jie; Zou, Jian; Yu, Xiao-Feng

    2011-03-07

    To quantitatively assess the relationship between coffee consumption and incidence of pancreatic cancer in a meta-analysis of cohort studies. We searched MEDLINE, EMBASE, Science Citation Index Expanded and bibliographies of retrieved articles. Studies were included if they reported relative risks (RRs) and corresponding 95% CIs of pancreatic cancer with respect to frequency of coffee intake. We performed random-effects meta-analyses and meta-regressions of study-specific incremental estimates to determine the risk of pancreatic cancer associated with a 1 cup/d increment in coffee consumption. Fourteen studies met the inclusion criteria, which included 671,080 individuals (1496 cancer events) with an average follow-up of 14.9 years. Compared with individuals who did not drink or seldom drank coffee per day, the pooled RR of pancreatic cancer was 0.82 (95% CI: 0.69-0.95) for regular coffee drinkers, 0.86 (0.76-0.96) for low to moderate coffee drinkers, and 0.68 (0.51-0.84) for high drinkers. In subgroup analyses, we noted that, coffee drinking was associated with a reduced risk of pancreatic cancer in men, while this association was not seen in women. These associations were also similar in studies from North America, Europe, and the Asia-Pacific region. Findings from this meta-analysis suggest that there is an inverse relationship between coffee drinking and risk of pancreatic cancer.

  6. Lipoprotein (a) as a risk factor for ischemic stroke: a meta-analysis.

    Science.gov (United States)

    Nave, Alexander H; Lange, Kristin S; Leonards, Christopher O; Siegerink, Bob; Doehner, Wolfram; Landmesser, Ulf; Steinhagen-Thiessen, Elisabeth; Endres, Matthias; Ebinger, Martin

    2015-10-01

    Lipoprotein (a) [Lp(a)] harbors atherogenic potential but its role as a risk factor for ischemic stroke remains controversial. We conducted a meta-analysis to determine the relative strength of the association between Lp(a) and ischemic stroke and identify potential subgroup-specific risk differences. A systematic search using the MeSH terms "lipoproteins" OR "lipoprotein a" AND "stroke" was performed in PubMed and ScienceDirect for case-control studies from June 2006 and prospective cohort studies from April 2009 until December 20th 2014. Data from eligible papers published before these dates were reviewed and extracted from previous meta-analyses. Studies that assessed the relationship between Lp(a) levels and ischemic stroke and reported generic data-i.e. odds ratio [OR], hazard ratio, or risk ratio [RR]-were eligible for inclusion. Studies that not distinguish between ischemic and hemorrhagic stroke and transient ischemic attack were excluded. Random effects meta-analyses with mixed-effects meta-regression were performed by pooling adjusted OR or RR. A total of 20 articles comprising 90,904 subjects and 5029 stroke events were eligible for the meta-analysis. Comparing high with low Lp(a) levels, the pooled estimated OR was 1.41 (95% CI, 1.26-1.57) for case-control studies (n = 11) and the pooled estimated RR was 1.29 (95% CI, 1.06-1.58) for prospective studies (n = 9). Sex-specific differences in RR were inconsistent between case-control and prospective studies. Study populations with a mean age of ≤55 years had an increased RR compared to older study populations. Reported Lp(a) contrast levels and ischemic stroke subtype significantly contributed to the heterogeneity observed in the analyses. Elevated Lp(a) is an independent risk factor for ischemic stroke and may be especially relevant for young stroke patients. Sex-specific risk differences remain conflicting. Further studies in these subgroups may be warranted. Copyright © 2015 Elsevier Ireland Ltd. All

  7. Automatic incrementalization of Prolog based static analyses

    DEFF Research Database (Denmark)

    Eichberg, Michael; Kahl, Matthias; Saha, Diptikalyan

    2007-01-01

    Modem development environments integrate various static analyses into the build process. Analyses that analyze the whole project whenever the project changes are impractical in this context. We present an approach to automatic incrementalization of analyses that are specified as tabled logic prog...

  8. MetaGenyo: a web tool for meta-analysis of genetic association studies.

    Science.gov (United States)

    Martorell-Marugan, Jordi; Toro-Dominguez, Daniel; Alarcon-Riquelme, Marta E; Carmona-Saez, Pedro

    2017-12-16

    Genetic association studies (GAS) aims to evaluate the association between genetic variants and phenotypes. In the last few years, the number of this type of study has increased exponentially, but the results are not always reproducible due to experimental designs, low sample sizes and other methodological errors. In this field, meta-analysis techniques are becoming very popular tools to combine results across studies to increase statistical power and to resolve discrepancies in genetic association studies. A meta-analysis summarizes research findings, increases statistical power and enables the identification of genuine associations between genotypes and phenotypes. Meta-analysis techniques are increasingly used in GAS, but it is also increasing the amount of published meta-analysis containing different errors. Although there are several software packages that implement meta-analysis, none of them are specifically designed for genetic association studies and in most cases their use requires advanced programming or scripting expertise. We have developed MetaGenyo, a web tool for meta-analysis in GAS. MetaGenyo implements a complete and comprehensive workflow that can be executed in an easy-to-use environment without programming knowledge. MetaGenyo has been developed to guide users through the main steps of a GAS meta-analysis, covering Hardy-Weinberg test, statistical association for different genetic models, analysis of heterogeneity, testing for publication bias, subgroup analysis and robustness testing of the results. MetaGenyo is a useful tool to conduct comprehensive genetic association meta-analysis. The application is freely available at http://bioinfo.genyo.es/metagenyo/ .

  9. Safety analyses for sodium-cooled fast reactors with pelletized and sphere-pac oxide fuels within the FP-7 European project PELGRIMM - 15386

    International Nuclear Information System (INIS)

    Maschek, W.; Andriolo, L.; Matzerath-Boccaccini, C.; Delage, F.; Parisi, C.; Del Nevo, A.; Abbate, G.; Schmitt, D.

    2015-01-01

    The European FP-7 project PELGRIMM addresses the development of Minor-Actinide (MA) bearing oxide fuel for Sodium-cooled Fast Reactors. Optionally, both MA homogeneous recycling and heterogeneous recycling is investigated with pellet and sphere-pac fuel. A first safety assessment of sphere-pac fuelled cores should be given in the Work Package 4 of the project. This assessment is in continuity with the former FP-7 CP-ESFR project. Within the CP-ESFR project the CONF2 core design has been developed characterized by a core with a large upper sodium plenum to reduce the coolant void worth. This optimized core has been chosen for the safety analyses in PELGRIMM. The task within the PELGRIMM project is thus a safety assessment of the CONF2 core loaded either with pellets or with sphere-pac fuel. The investigations started with the design of the CONF2 core with sphere-pac fuel and the determination of core safety parameters and burn-up behavior. The neutronic analyses have been performed with the MCNPX code. Variants of the CONF2 core contain up to 4% Am in the fuel. The results revealed an extended void worth (core + upper plenum) for an Am free core of 1 up to 3 dollars for the 4% Am core. Thermal-hydraulic design analyses have been performed by RELAP5-3D. The accident simulations should be performed by different codes, some of which focus on the initiation phase of the accident, as SAS4A, BELLA and the MAT5DYN code, whereas the SIMMER-III code will also deal with the later accident phases and a potential whole core melting. The codes had to be adapted to the specifics of the sphere-pac fuel, in particular to the thermal conductivity and gap conditions. Analyses showed that the safety assessment has to take into account two main phases. Starting up the core, the green fuel shows a reduced fuel thermal conductivity. After restructuring within a couple of hours, the thermal conductivity recovers and the fuel temperature decreases. The main objective of the safety analyses

  10. Meta-analyses of Theory use in Medication Adherence Intervention Research

    Science.gov (United States)

    Conn, Vicki S.; Enriquez, Maithe; Ruppar, Todd M.; Chan, Keith C.

    2016-01-01

    Objective This systematic review applied meta-analytic procedures to integrate primary research that examined theory- or model-linked medication adherence interventions. Methods Extensive literature searching strategies were used to locate trials testing interventions with medication adherence behavior outcomes measured by electronic event monitoring, pharmacy refills, pill counts, and self-reports. Random-effects model analysis was used to calculate standardized mean difference effect sizes for medication adherence outcomes. Results Codable data were extracted from 146 comparisons with 19,348 participants. The most common theories and models were social cognitive theory and motivational interviewing. The overall weighted effect size for all interventions comparing treatment and control participants was 0.294. The effect size for interventions based on single-theories was 0.323 and for multiple-theory interventions was 0.214. Effect sizes for individual theories and models ranged from 0.041 to 0.447. The largest effect sizes were for interventions based on the health belief model (0.477) and adult learning theory (0.443). The smallest effect sizes were for interventions based on PRECEDE (0.041) and self-regulation (0.118). Conclusion These findings suggest that theory- and model-linked interventions have a significant but modest effect on medication adherence outcomes. PMID:26931748

  11. Comparative efficacy and acceptability of psychotherapies for depression in children and adolescents: a systematic review and network meta-analysis

    NARCIS (Netherlands)

    Zhou, X.; Hetrick, S.E.; Cuijpers, P.; Qin, B.; Barth, J.; Whittington, C.J.; Cohen, D.; del Giovane, C.; Liu, Y.; Micheal, K.D.; Zhang, Y.; Weisz, J.R.; Xie, P.

    2015-01-01

    Previous meta-analyses of psychotherapies for child and adolescent depression were limited because of the small number of trials with direct comparisons between two treatments. A network meta-analysis, a novel approach that integrates direct and indirect evidence from randomized controlled studies,

  12. Meta-analysis of high-latitude nitrogen-addition and warming studies imply ecological mechanisms overlooked by land models

    Science.gov (United States)

    Bouskill, N. J.; Riley, W. J.; Tang, J.

    2014-08-01

    Accurate representation of ecosystem processes in land models is crucial for reducing predictive uncertainty in energy and greenhouse gas feedbacks with the atmosphere. Here we describe an observational and modeling meta-analysis approach to benchmark land models, and apply the method to the land model CLM4.5 with two versions of belowground biogeochemistry. We focused our analysis on the above and belowground high-latitude ecosystem responses to warming and nitrogen addition, and identified mechanisms absent, or poorly parameterized in CLM4.5. While the two model versions predicted similar trajectories for soil carbon stocks following both types of perturbation, other variables (e.g., belowground respiration) differed from the observations in both magnitude and direction, indicating the underlying mechanisms are inadequate for representing high-latitude ecosystems. The observational synthesis attribute these differences to missing representations of microbial dynamics, characterization of above and belowground functional processes, and nutrient competition. We use the observational meta-analyses to discuss potential approaches to improving the current models (e.g., the inclusion of dynamic vegetation or different microbial functional guilds), however, we also raise a cautionary note on the selection of data sets and experiments to be included in a meta-analysis. For example, the concentrations of nitrogen applied in the synthesized field experiments (average =72 kg ha-1 yr-1) are many times higher than projected soil nitrogen concentrations (from nitrogen deposition and release during mineralization), which preclude a rigorous evaluation of the model responses to nitrogen perturbation. Overall, we demonstrate here that elucidating ecological mechanisms via meta-analysis can identify deficiencies in both ecosystem models and empirical experiments.

  13. Clinical Research That Matters: Designing Outcome-Based Research for Older Adults to Qualify for Systematic Reviews and Meta-Analyses.

    Science.gov (United States)

    Lee, Jeannie K; Fosnight, Susan M; Estus, Erica L; Evans, Paula J; Pho, Victoria B; Reidt, Shannon; Reist, Jeffrey C; Ruby, Christine M; Sibicky, Stephanie L; Wheeler, Janel B

    2018-01-01

    Though older adults are more sensitive to the effects of medications than their younger counterparts, they are often excluded from manufacturer-based clinical studies. Practice-based research is a practical method to identify medication-related effects in older patients. This research also highlights the role of a pharmacist in improving care in this population. A single study rarely has strong enough evidence to change geriatric practice, unless it is a large-scale, multisite, randomized controlled trial that specifically targets older adults. It is important to design studies that may be used in systematic reviews or meta-analyses that build a stronger evidence base. Recent literature has documented a gap in advanced pharmacist training pertaining to research skills. In this paper, we hope to fill some of the educational gaps related to research in older adults. We define best practices when deciding on the type of study, inclusion and exclusion criteria, design of the intervention, how outcomes are measured, and how results are reported. Well-designed studies increase the pool of available data to further document the important role that pharmacists have in optimizing care of older patients.

  14. Meta-analysis: Problems with Russian Publications.

    Science.gov (United States)

    Verbitskaya, E V

    2015-01-01

    Meta-analysis is a powerful tool to identify Evidence Based medical technologies (interventions) for use in every day practice. Meta-analysis uses statistical approaches to combine results from multiple studies in an effort to increase power (over individual studies), improve estimates of the size of the effect and/or to resolve uncertainty when reports disagree. Meta-analysis is a quantitative, formal study design used to systematically assess previous research studies to derive conclusions from this research. Meta-analysis may provide more precise estimate of the effect of treatment or risk factor for a disease, or other outcomes, than any individual study contributing to the pooled analysis.We have quite a substantial number of Russian medical publications, but not so many Meta-Analyses published in Russian. Russian publications are cited in English language papers not so often. A total of 90% of clinical studies included in published Meta-Analyses incorporate only English language papers. International studies or papers with Russian co-authors are published in English language. The main question is: what is the problem with inclusion of Russian medical publications in Meta-Analysis? The main reasons for this are the following: 1) It is difficult to find Russian papers, difficult to work with them and to work with Russian journals:a. There are single Russian Biomedical Journals, which are translated into English and are included in databases (PubMed, Scopus and other), despite the fact that all of them have English language abstracts.b. The majority the meta-analyses authors use in their work different citation management software such as the Mendeley, Reference Manager, ProCite, EndNote, and others. These citation management systems allow scientists to organize their own literature databases with internet searches and have adds-on for the Office programs what makes process of literature citation very convenient. The Internet sites of the majority of

  15. Resurrecting Brinley Plots for a Novel Use: Meta-Analyses of Functional Brain Imaging Data in Older Adults

    Directory of Open Access Journals (Sweden)

    Ann M. Peiffer

    2008-01-01

    Full Text Available By plotting response times of young and older adults across a variety of tasks, Brinley spurred investigation and debate into the theory of general cognitive slowing. Though controversial, Brinley plots can assess between-task differences, the impact of increasing task demand, and the relationship between responses in two groups of subjects. Since a relationship exists between response times and the blood-oxygen level dependent (BOLD signal of functional MRI (fMRI, Brinley's plotting method could be applied as a meta-analysis tool in fMRI studies of aging. Here, fledgling “Peiffer plots” are discussed for their potential impact on understanding general cognitive brain activity in aging. Preliminary results suggest that general cognitive slowing may be localized at the sensorimotor transformation in the precentral gyrus. Although this meta-analysis method is naturally used with imaging studies of aging, theoretically it may be applied to other study pairs (e.g., schizophrenic versus normal or imaging datasets (e.g., PET.

  16. Depression as a risk factor for the onset of type 2 diabetes mellitus. A meta-analysis

    DEFF Research Database (Denmark)

    Knol, M J; Twisk, Jos W R; Beekman, Aartjan T F

    2006-01-01

    the latter association by reviewing the literature and conducting a meta-analysis of longitudinal studies on this topic. METHODS: Medline and PsycInfo were searched for articles published up to January 2005. All studies that examined the relationship between depression and the onset of type 2 diabetes were...... included. Pooled relative risks were calculated using fixed and random effects models. To explore sources of heterogeneity between studies, subgroup analyses and meta-regression analyses were performed. RESULTS: Nine studies met our inclusion criteria for this meta-analysis. The pooled relative risk was 1......AIMS/HYPOTHESIS: Evidence strongly suggests that depression and type 2 diabetes are associated, but the direction of the association is still unclear. Depression may occur as a consequence of having diabetes, but may also be a risk factor for the onset of type 2 diabetes. This study examined...

  17. Disruptions in foster care: A review and meta-analysis

    NARCIS (Netherlands)

    Oosterman, M.; Schuengel, C.; Slot, N.W.; Bullens, R.A.R.; Doreleijers, T.A.H.

    2007-01-01

    This review examined risk and protective factors associated with placement breakdown across k = 26 studies of 20,650 children in foster families. A series of meta-analyses were performed to assess the average effect sizes across multiple studies on the same factors. Older age at placement (k = 15),

  18. Meta-analysis with R

    CERN Document Server

    Schwarzer, Guido; Rücker, Gerta

    2015-01-01

    This book provides a comprehensive introduction to performing meta-analysis using the statistical software R. It is intended for quantitative researchers and students in the medical and social sciences who wish to learn how to perform meta-analysis with R. As such, the book introduces the key concepts and models used in meta-analysis. It also includes chapters on the following advanced topics: publication bias and small study effects; missing data; multivariate meta-analysis, network meta-analysis; and meta-analysis of diagnostic studies.  .

  19. Meniscal allograft transplantation: a meta-analysis

    Directory of Open Access Journals (Sweden)

    De Bruycker Manolito

    2017-01-01

    Full Text Available Purpose: This meta-analysis evaluates the mid- to long-term survival outcome of MAT (meniscal allograft transplantation. Potential prognosticators, with particular focus on chondral status and age of the patient at the time of transplantation, were also analysed. Study design: Meta-analysis. Methods: An online database search was performed using following search string: “meniscal allograft transplantation” and “outcome”. A total of 65 articles were analysed for a total of 3157 performed MAT with a mean follow-up of 5.4 years. Subjective and clinical data was analysed. Results: The subjective and objective results of 2977 patients (3157 allografts were analysed; 70% were male, 30% were female. Thirty-eight percent received an isolated MAT. All other patients underwent at least one concomitant procedure. Lysholm, Knee injury and Osteoarthritis Outcome (KOOS, International Knee Documentation Committee (IKDC and Visual Analogue Scale (VAS scores were analysed. All scores showed a good patient satisfaction at long-term follow-up. The mean overall survival rate was 80.9%. Complication rates were comparable to standard meniscal repair surgery. There was a degenerative evolution in osteoarthritis with at least one grade in 1760 radiographically analysed patients. Concomitant procedures seem to have no effect on the outcome. Age at transplantation is a negative prognosticator. The body mass index (BMI of the patient shows a slightly negative correlation with the outcome of MAT. Conclusions: MAT is a viable solution for the younger patient with chronic pain in the meniscectomised knee joint. The complications are not severe and comparable to meniscal repair. The overall failure rate at final follow-up is acceptable and the allograft heals well in most cases, but MAT cannot be seen as a definitive solution for post-meniscectomy pain. The correct approach to the chronic painful total meniscectomised knee joint thus requires consideration of all

  20. Meta-synthesis on learners' experience of aggression in secondary ...

    African Journals Online (AJOL)

    This meta-synthesis is on research conducted by different researchers in a team research project on learners' experience of aggression in secondary schools in South Africa. The objective was to obtain a broader understanding of their experience of aggression in different contexts in South Africa, as well as possible ways to ...

  1. CSNI Project for Fracture Analyses of Large-Scale International Reference Experiments (Project FALSIRE)

    International Nuclear Information System (INIS)

    Bass, B.R.; Pugh, C.E.; Keeney-Walker, J.; Schulz, H.; Sievers, J.

    1993-06-01

    This report summarizes the recently completed Phase I of the Project for Fracture Analysis of Large-Scale International Reference Experiments (Project FALSIRE). Project FALSIRE was created by the Fracture Assessment Group (FAG) of Principal Working Group No. 3 (PWG/3) of the Organization for Economic Cooperation and Development (OECD)/Nuclear Energy Agency's (NEA's) Committee on the Safety of Nuclear Installations (CSNI). Motivation for the project was derived from recognition by the CSNI-PWG/3 that inconsistencies were being revealed in predictive capabilities of a variety of fracture assessment methods, especially in ductile fracture applications. As a consequence, the CSNI/FAG was formed to evaluate fracture prediction capabilities currently used in safety assessments of nuclear components. Members are from laboratories and research organizations in Western Europe, Japan, and the United States of America (USA). On behalf of the CSNI/FAG, the US Nuclear Regulatory Commission's (NRC's) Heavy-Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory (ORNL) and the Gesellschaft fuer Anlagen--und Reaktorsicherheit (GRS), Koeln, Federal Republic of Germany (FRG) had responsibility for organization arrangements related to Project FALSIRE. The group is chaired by H. Schulz from GRS, Koeln, FRG

  2. CSNI Project for Fracture Analyses of Large-Scale International Reference Experiments (Project FALSIRE)

    Energy Technology Data Exchange (ETDEWEB)

    Bass, B.R.; Pugh, C.E.; Keeney-Walker, J. [Oak Ridge National Lab., TN (United States); Schulz, H.; Sievers, J. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Koeln (Gemany)

    1993-06-01

    This report summarizes the recently completed Phase I of the Project for Fracture Analysis of Large-Scale International Reference Experiments (Project FALSIRE). Project FALSIRE was created by the Fracture Assessment Group (FAG) of Principal Working Group No. 3 (PWG/3) of the Organization for Economic Cooperation and Development (OECD)/Nuclear Energy Agency`s (NEA`s) Committee on the Safety of Nuclear Installations (CSNI). Motivation for the project was derived from recognition by the CSNI-PWG/3 that inconsistencies were being revealed in predictive capabilities of a variety of fracture assessment methods, especially in ductile fracture applications. As a consequence, the CSNI/FAG was formed to evaluate fracture prediction capabilities currently used in safety assessments of nuclear components. Members are from laboratories and research organizations in Western Europe, Japan, and the United States of America (USA). On behalf of the CSNI/FAG, the US Nuclear Regulatory Commission`s (NRC`s) Heavy-Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory (ORNL) and the Gesellschaft fuer Anlagen--und Reaktorsicherheit (GRS), Koeln, Federal Republic of Germany (FRG) had responsibility for organization arrangements related to Project FALSIRE. The group is chaired by H. Schulz from GRS, Koeln, FRG.

  3. Meta-analysis of the effect of road safety campaigns on accidents.

    Science.gov (United States)

    Phillips, Ross Owen; Ulleberg, Pål; Vaa, Truls

    2011-05-01

    A meta-analysis of 67 studies evaluating the effect of road safety campaigns on accidents is reported. A total of 119 results were extracted from the studies, which were reported in 12 different countries between 1975 and 2007. After allowing for publication bias and heterogeneity of effects, the weighted average effect of road safety campaigns is a 9% reduction in accidents (with 95% confidence that the weighted average is between -12 and -6%). To account for the variability of effects measured across studies, data were collected to characterise aspects of the campaign and evaluation design associated with each effect, and analysed to identify a model of seven campaign factors for testing by meta-regression. The model was tested using both fixed and random effect meta-regression, and dependency among effects was accounted for by aggregation. These analyses suggest positive associations between accident reduction and the use of personal communication or roadside media as part of a campaign delivery strategy. Campaigns with a drink-driving theme were also associated with greater accident reductions, while some of the analyses suggested that accompanying enforcement and short campaign duration (less than one month) are beneficial. Overall the results are consistent with the idea that campaigns can be more effective in the short term if the message is delivered with personal communication in a way that is proximal in space and time to the behaviour targeted by the campaign. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Parental experiences of providing skin-to-skin care to their newborn infant—Part 2: A qualitative meta-synthesis

    Directory of Open Access Journals (Sweden)

    Agneta Anderzén-Carlsson

    2014-10-01

    Full Text Available Aim: To synthesize and interpret qualitative research findings focusing on parental experiences of skin-to-skin care (SSC for newborn infants. Background: SSC induces many benefits for newborn infants and their parents. Three meta-analyses have been conducted on physiological outcomes, but no previous qualitative meta-synthesis on parental experiences of SSC has been identified. Design: The present meta-synthesis was guided by the methodology described by Paterson and co-workers. Data sources: Four databases were searched, without year or language limitations, up until December 2013. Manual searches were also performed. The searches and subsequent quality appraisal resulted in the inclusion of 29 original qualitative papers from 9 countries, reporting experiences from 401 mothers and 94 fathers. Review methods: The meta-synthesis entails a meta-data analysis, analysis of meta-method, and meta-theory in the included primary studies. Based on the three analyses, the meta-synthesis represents a new interpretation of a phenomenon. The results of the meta-data analysis have been presented as a qualitative systematic review in a separate paper. Results: When synthesizing and interpreting the findings from the included analyses, a theoretical model of Becoming a parent under unfamiliar circumstances emerged. Providing SSC seems to be a restorative as well as an energy-draining experience. A supportive environment has been described as facilitating the restorative experience, whereas obstacles in the environment seem to make the provision of SSC energy-draining for parents. When the process is experienced as positive, it facilitates the growth of parental self-esteem and makes the parents ready to assume full responsibility for their child. Conclusion: The results show that SSC can be interpreted not only as a family-including and important health care intervention but also in terms of actually becoming a parent. The process of becoming a parent in this

  5. MTLRP genetic polymorphism (214C>A) was associated with Type 2 diabetes in Caucasian population: a meta-analysis

    OpenAIRE

    Chen, Li-Li; Han, Song-Mei; Tang, Fei-Fei; Li, Qiang

    2014-01-01

    Background Previous studies reported the relation between MTLRP genetic polymorphism and type 2 diabetes, however, the conclusion were conflicting. In the present study, we performed a meta-analysis to reveal this association. Methods Literature retrieval, selection and assessment, data extraction, and meta-analyses were performed according to the RevMan 5.0 guidelines. In the meta-analysis, we utilized random-effect model or fixed-effect model to pool the Odds ratio (OR) according to the tes...

  6. Intrinsic motivation and extrinsic incentives jointly predict performance: a 40-year meta-analysis.

    Science.gov (United States)

    Cerasoli, Christopher P; Nicklin, Jessica M; Ford, Michael T

    2014-07-01

    More than 4 decades of research and 9 meta-analyses have focused on the undermining effect: namely, the debate over whether the provision of extrinsic incentives erodes intrinsic motivation. This review and meta-analysis builds on such previous reviews by focusing on the interrelationship among intrinsic motivation, extrinsic incentives, and performance, with reference to 2 moderators: performance type (quality vs. quantity) and incentive contingency (directly performance-salient vs. indirectly performance-salient), which have not been systematically reviewed to date. Based on random-effects meta-analytic methods, findings from school, work, and physical domains (k = 183, N = 212,468) indicate that intrinsic motivation is a medium to strong predictor of performance (ρ = .21-45). The importance of intrinsic motivation to performance remained in place whether incentives were presented. In addition, incentive salience influenced the predictive validity of intrinsic motivation for performance: In a "crowding out" fashion, intrinsic motivation was less important to performance when incentives were directly tied to performance and was more important when incentives were indirectly tied to performance. Considered simultaneously through meta-analytic regression, intrinsic motivation predicted more unique variance in quality of performance, whereas incentives were a better predictor of quantity of performance. With respect to performance, incentives and intrinsic motivation are not necessarily antagonistic and are best considered simultaneously. Future research should consider using nonperformance criteria (e.g., well-being, job satisfaction) as well as applying the percent-of-maximum-possible (POMP) method in meta-analyses. PsycINFO Database Record (c) 2014 APA, all rights reserved.

  7. Voxelwise meta-analysis of gray matter abnormalities in dementia with Lewy bodies

    International Nuclear Information System (INIS)

    Zhong, JianGuo; Pan, PingLei; Dai, ZhenYu; Shi, HaiCun

    2014-01-01

    Highlights: • We first report the meta-analyses of GM anomalies by VBM studies in DLB. • Lateral temporal/insular and lenticular nucleus/insular cortex atrophy were detected. • A characteristic pattern of GM changes underpinned DLB. - Abstract: Background: Increasing neuroimaging studies have revealed brain gray matter (GM) atrophy by voxel-based morphometry (VBM) studies in patients with dementia with Lewy bodies (DLB) relative to healthy controls. However, the spatial localization of GM abnormalities reported in the existing studies is heterogeneous. Here, we aimed to investigate concurrence across VBM studies to help clarify the structural abnormalities underpinning this condition. Methods: A systematic search for VBM studies of DLB patients and healthy controls published in PubMed database from January 2000 to March 2014 was conducted. A quantitative meta-analysis of whole-brain VBM studies in DLB patients and healthy controls was performed by means of Anisotropic Effect Size version of Signed Differential Mapping (AES-SDM) software package. Results: Seven studies comprising 218 DLB patients and 219 healthy controls were included in the present study. Compared to healthy subjects, the patients group showed consistent decreased GM in right lateral temporal/insular cortex and left lenticular nucleus/insular cortex. The results remained largely unchanged in the following jackknife sensitivity analyses. Meta-regression analysis indicated an increased probability of finding brain atrophy in left superior temporal gyrus in patients with lower MMSE scores. Conclusions: The present meta-analysis quantitatively demonstrates a characteristic pattern of GM alternations that contributed to the understanding of pathophysiology underlying DLB. Future studies will benefit from employing meta-analytical comparisons to other dementia subtypes with solid evidence to extend these findings.

  8. Voxelwise meta-analysis of gray matter abnormalities in dementia with Lewy bodies

    Energy Technology Data Exchange (ETDEWEB)

    Zhong, JianGuo; Pan, PingLei [Department of Neurology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China); Dai, ZhenYu [Department of Radiology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China); Shi, HaiCun, E-mail: yc3yhcshi@gmail.com [Department of Neurology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China)

    2014-10-15

    Highlights: • We first report the meta-analyses of GM anomalies by VBM studies in DLB. • Lateral temporal/insular and lenticular nucleus/insular cortex atrophy were detected. • A characteristic pattern of GM changes underpinned DLB. - Abstract: Background: Increasing neuroimaging studies have revealed brain gray matter (GM) atrophy by voxel-based morphometry (VBM) studies in patients with dementia with Lewy bodies (DLB) relative to healthy controls. However, the spatial localization of GM abnormalities reported in the existing studies is heterogeneous. Here, we aimed to investigate concurrence across VBM studies to help clarify the structural abnormalities underpinning this condition. Methods: A systematic search for VBM studies of DLB patients and healthy controls published in PubMed database from January 2000 to March 2014 was conducted. A quantitative meta-analysis of whole-brain VBM studies in DLB patients and healthy controls was performed by means of Anisotropic Effect Size version of Signed Differential Mapping (AES-SDM) software package. Results: Seven studies comprising 218 DLB patients and 219 healthy controls were included in the present study. Compared to healthy subjects, the patients group showed consistent decreased GM in right lateral temporal/insular cortex and left lenticular nucleus/insular cortex. The results remained largely unchanged in the following jackknife sensitivity analyses. Meta-regression analysis indicated an increased probability of finding brain atrophy in left superior temporal gyrus in patients with lower MMSE scores. Conclusions: The present meta-analysis quantitatively demonstrates a characteristic pattern of GM alternations that contributed to the understanding of pathophysiology underlying DLB. Future studies will benefit from employing meta-analytical comparisons to other dementia subtypes with solid evidence to extend these findings.

  9. Options for a health system researcher to choose in Meta Review (MR approaches-Meta Narrative (MN and Meta Triangulation (MT

    Directory of Open Access Journals (Sweden)

    Sanjeev Davey

    2015-01-01

    Full Text Available Two new approaches in systematic reviewing i.e. Meta-narrative review(MNR (which a health researcher can use for topics which are differently conceptualized and studied by different types of researchers for policy decisions and Meta-triangulation review(MTR (done to build theory for studying multifaceted phenomena characterized by expansive and contested research domains are ready for penetration in an arena of health system research. So critical look at which approach in Meta-review is better i.e. Meta-narrative review or Meta-triangulation review, can give new insights to a health system researcher. A systematic review on 2 key words-"meta-narrative review" and "meta-triangulation review" in health system research, were searched from key search engines, such as Pubmed, Cochrane library, Bio-med Central and Google Scholar etc till 21st March 2014 since last 20 years. Studies from both developed and developing world were included in any form and scope to draw final conclusions. However unpublished data from thesis was not included in systematic review. Meta-narrative review is a type of systematic review which can be used for a wide range of topics and questions involving making judgments and inferences in public health. On the other hand Meta-triangulation review is a three-phased, qualitative meta-analysis process which can be used to explore variations in the assumptions of alternative paradigms, gain insights into these multiple paradigms at one point of time and addresses emerging themes and the resulting theories.

  10. Novel non-HLA-susceptible regions determined by meta-analysis of ...

    Indian Academy of Sciences (India)

    We identified novel non-HLA-susceptible regions for ankylosing spondylitis (AS) by applying the genome-search-meta-analysis (GSMA) method to combine the previous four AS genomewide scan studies including 479 families with 1175 affected individuals. Three original genomescans were mainly analysed for Caucasian ...

  11. A meta-analysis of social networking online and social capital

    NARCIS (Netherlands)

    Liu, Dong; Ainsworth, Sarah E.; Baumeister, Roy F.

    2016-01-01

    Social networking sites offer new avenues for interpersonal communication that may enable people to build social capital. The meta-analyses reported in this paper evaluated the relationship between social network site (SNS) use and 2 types of social capital: bridging social capital and bonding

  12. Alcohol Consumption Increases Post-Operative Infection but Not Mortality: A Systematic Review and Meta-Analysis.

    Science.gov (United States)

    Shabanzadeh, Daniel Mønsted; Sørensen, Lars Tue

    2015-12-01

    Alcohol consumption causes multiple comorbidities with potentially negative outcome after operations. The aims are to study the association between alcohol consumption and post-operative non-surgical site infections and mortality and to determine the impact of peri-operative interventions. MEDLINE, Embase, and The Cochrane Library were searched systematically. Observational studies reporting patients with a defined amount of alcohol consumption and randomized controlled trials (RCTs) aimed at reducing outcomes were included. Meta-analyses were performed separately for observational studies and RCTs. Thirteen observational studies and five RCTs were identified. Meta-analyses of observational studies showed more infections in those consuming more than two units of alcohol per day compared with drinking less in both unadjusted and adjusted data. No association between alcohol consumption and mortality was found. Meta-analyses of RCTs showed that interventions reduce infections but not mortality in patients with alcohol abuse. Consumption of more than two units of alcohol per day increases post-operative non-surgical site infections. Alcohol-refraining interventions in patients with high daily alcohol consumption appear to reduce infections. The impact in patients with lesser intake is unknown. Further studies are needed.

  13. Primary molar pulpotomy: a systematic review and network meta-analysis.

    Science.gov (United States)

    Lin, Po-Yen; Chen, Hsueh-Szu; Wang, Yu-Hsiang; Tu, Yu-Kang

    2014-09-01

    Pulpotomy is a common procedure to treat asymptomatic reversible pulpitis in primary molars. The aim of this study is to undertake a systematic review and a network meta-analysis to compare the clinical and radiographic outcomes of different pulpotomy procedures in primary molars. Three authors performed data extraction independently and in duplicate using data collection forms. Disagreements were resolved by discussion. An electronic literature search was performed within MEDLINE (via PubMed), ScienceDirect, Web of Science, Cochrane, and ClinicalKey databases until December 2012. Medications for pulpotomy including formocresol, ferric sulfate, calcium hydroxide, and mineral trioxide aggregate (MTA), and laser pulpotomy are compared using Bayesian network meta-analyses. The outcome is the odds ratio for clinical and radiographic failure including premature tooth loss at 12 and 24 months after treatments amongst different treatment procedures. 37 studies were included in the systematic review, and 22 of them in the final network meta-analyses. After 18-24 months, in terms of treatment failure, the odds ratio for calcium hydroxide vs. formocresol was 1.94 [95% credible interval (CI): 1.11, 3.25]; 3.38 (95% CI: 1.37, 8.61) for lasers vs. formocresol; 2.16 (95% CI: 1.12, 4.31) for calcium hydroxide vs. ferric sulfate; 3.73 (95% CI: 1.27, 11.67) for lasers vs. ferric sulfate; 0.47 (95% CI: 0.26, 0.83) for MTA vs. calcium hydroxide; 3.76 (95% CI: 1.39, 10.08) for lasers vs. After 18-24 months, formocresol, ferric sulfate, and MTA showed significantly better clinical and radiographic outcomes than calcium hydroxide and laser therapies in primary molar pulpotomies. The network meta-analyses showed that MTA is the first choice for primary molar pulpotomies. However, if treatment cost is an issue, especially when the treated primary molars are going to be replaced by permanent teeth, ferric sulfate may be the choice. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Conventional vs. e-learning in nursing education: A systematic review and meta-analysis.

    Science.gov (United States)

    Voutilainen, Ari; Saaranen, Terhi; Sormunen, Marjorita

    2017-03-01

    By and large, in health professions training, the direction of the effect of e-learning, positive or negative, strongly depends on the learning outcome in question as well as on learning methods which e-learning is compared to. In nursing education, meta-analytically generated knowledge regarding the comparisons between conventional and e-learning is scarce. The aim of this review is to discover the size of the effect of e-learning on learning outcomes in nursing education and to assess the quality of studies in which e-learning has been compared to conventional learning. A systematic search of six electronic databases, PubMed, Ovid MEDLINE®, CINAHL (EBSCOhost), Cochrane Library, PsycINFO, and ERIC, was conducted in order to identify relevant peer-reviewed English language articles published between 2011 and 2015. The quality of the studies included as well as the risk of bias in each study was assessed. A random-effects meta-analysis was performed to generate a pooled mean difference in the learning outcome. Altogether, 10 studies were eligible for the quality assessment and meta-analysis. Nine studies were evaluated as good quality studies, but not without a risk of bias. Performance bias caused a high risk in nearly all the studies. In the meta-analysis, an e-learning method resulted in test scores that were, on average, five points higher than a conventional method on a 0-100 scale. Heterogeneity between the studies was very large. The size and direction of the effect of a learning method on learning outcomes appeared to be strongly situational. We suggest that meta-regressions should be performed instead of basic meta-analyses in order to reveal factors that cause variation in the learning outcomes of nursing education. It might be necessary to perform separate meta-analyses between e-learning interventions aimed at improving nursing knowledge and those aimed at improving nursing skills. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Chemotherapy in advanced ovarian cancer: four systematic meta-analyses of individual patient data from 37 randomized trials. Advanced Ovarian Cancer Trialists' Group.

    Science.gov (United States)

    Aabo, K.; Adams, M.; Adnitt, P.; Alberts, D. S.; Athanazziou, A.; Barley, V.; Bell, D. R.; Bianchi, U.; Bolis, G.; Brady, M. F.; Brodovsky, H. S.; Bruckner, H.; Buyse, M.; Canetta, R.; Chylak, V.; Cohen, C. J.; Colombo, N.; Conte, P. F.; Crowther, D.; Edmonson, J. H.; Gennatas, C.; Gilbey, E.; Gore, M.; Guthrie, D.; Yeap, B. Y.

    1998-01-01

    The purpose of this systematic study was to provide an up to date and reliable quantitative summary of the relative benefits of various types of chemotherapy (non-platinum vs platinum, single-agent vs combination and carboplatin vs cisplatin) in the treatment of advanced ovarian cancer. Also, to investigate whether well-defined patient subgroups benefit more or less from cisplatin- or carboplatin-based therapy. Meta-analyses were based on updated individual patient data from all available randomized controlled trials (published and unpublished), including 37 trials, 5667 patients and 4664 deaths. The results suggest that platinum-based chemotherapy is better than non-platinum therapy, show a trend in favour of platinum combinations over single-agent platinum, and suggest that cisplatin and carboplatin are equally effective. There is no good evidence that cisplatin is more or less effective than carboplatin in any particular subgroup of patients. Images Figure 1 Figure 2 Figure 3 PMID:9836481

  16. Understanding large social-ecological systems: introducing the SESMAD project

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    Michael Cox

    2014-08-01

    Full Text Available This article introduces the Social-ecological systems meta-analysis database (SESMAD project, which is the project behind the case studies and synthetic articles contained in this special issue of the International Journal of the Commons. SESMAD is an internationally collaborative meta-analysis project that builds on previous seminally synthetic work on small-scale common-pool resource systems conducted at the Workshop in Political Theory and Policy Analysis at Indiana University. This project is guided by the following research question: can the variables found to be important in explaining outcomes on small-scale systems be scaled up to explain outcomes in large-scale environmental governance? In this special issue we report on our findings thus far through a set of case studies of large-scale environmental governance, a paper that describes our conceptual advances, and a paper that compares these five case studies to further examine our central research question.

  17. A Bayesian approach to meta-analysis of plant pathology studies.

    Science.gov (United States)

    Mila, A L; Ngugi, H K

    2011-01-01

    Bayesian statistical methods are used for meta-analysis in many disciplines, including medicine, molecular biology, and engineering, but have not yet been applied for quantitative synthesis of plant pathology studies. In this paper, we illustrate the key concepts of Bayesian statistics and outline the differences between Bayesian and classical (frequentist) methods in the way parameters describing population attributes are considered. We then describe a Bayesian approach to meta-analysis and present a plant pathological example based on studies evaluating the efficacy of plant protection products that induce systemic acquired resistance for the management of fire blight of apple. In a simple random-effects model assuming a normal distribution of effect sizes and no prior information (i.e., a noninformative prior), the results of the Bayesian meta-analysis are similar to those obtained with classical methods. Implementing the same model with a Student's t distribution and a noninformative prior for the effect sizes, instead of a normal distribution, yields similar results for all but acibenzolar-S-methyl (Actigard) which was evaluated only in seven studies in this example. Whereas both the classical (P = 0.28) and the Bayesian analysis with a noninformative prior (95% credibility interval [CRI] for the log response ratio: -0.63 to 0.08) indicate a nonsignificant effect for Actigard, specifying a t distribution resulted in a significant, albeit variable, effect for this product (CRI: -0.73 to -0.10). These results confirm the sensitivity of the analytical outcome (i.e., the posterior distribution) to the choice of prior in Bayesian meta-analyses involving a limited number of studies. We review some pertinent literature on more advanced topics, including modeling of among-study heterogeneity, publication bias, analyses involving a limited number of studies, and methods for dealing with missing data, and show how these issues can be approached in a Bayesian framework

  18. Dealing with missing standard deviation and mean values in meta-analysis of continuous outcomes: a systematic review.

    Science.gov (United States)

    Weir, Christopher J; Butcher, Isabella; Assi, Valentina; Lewis, Stephanie C; Murray, Gordon D; Langhorne, Peter; Brady, Marian C

    2018-03-07

    Rigorous, informative meta-analyses rely on availability of appropriate summary statistics or individual participant data. For continuous outcomes, especially those with naturally skewed distributions, summary information on the mean or variability often goes unreported. While full reporting of original trial data is the ideal, we sought to identify methods for handling unreported mean or variability summary statistics in meta-analysis. We undertook two systematic literature reviews to identify methodological approaches used to deal with missing mean or variability summary statistics. Five electronic databases were searched, in addition to the Cochrane Colloquium abstract books and the Cochrane Statistics Methods Group mailing list archive. We also conducted cited reference searching and emailed topic experts to identify recent methodological developments. Details recorded included the description of the method, the information required to implement the method, any underlying assumptions and whether the method could be readily applied in standard statistical software. We provided a summary description of the methods identified, illustrating selected methods in example meta-analysis scenarios. For missing standard deviations (SDs), following screening of 503 articles, fifteen methods were identified in addition to those reported in a previous review. These included Bayesian hierarchical modelling at the meta-analysis level; summary statistic level imputation based on observed SD values from other trials in the meta-analysis; a practical approximation based on the range; and algebraic estimation of the SD based on other summary statistics. Following screening of 1124 articles for methods estimating the mean, one approximate Bayesian computation approach and three papers based on alternative summary statistics were identified. Illustrative meta-analyses showed that when replacing a missing SD the approximation using the range minimised loss of precision and generally

  19. Clinical effects of pre-adjusted edgewise orthodontic brackets: a systematic review and meta-analysis.

    Science.gov (United States)

    Papageorgiou, Spyridon N; Konstantinidis, Ioannis; Papadopoulou, Konstantina; Jäger, Andreas; Bourauel, Christoph

    2014-06-01

    Fixed-appliance treatment is a major part of orthodontic treatment, but clinical evidence remains scarce. Objective of this systematic review was to investigate how the therapeutic effects and side-effects of brackets used during the fixed-appliance orthodontic treatment are affected by their characteristics. SEARCH METHODS AND SELECTION CRITERIA: We searched MEDLINE and 18 other databases through April 2012 without restrictions for randomized controlled trials and quasi-randomized controlled trials investigating any bracket characteristic. After duplicate selection and extraction procedures, risk of bias was assessed also in duplicate according to Cochrane guidelines and quality of evidence according to the Grades of Recommendation. Assessment, Development and Evaluation approach. Random-effects meta-analyses, subgroup analyses, and sensitivity analyses were performed with the corresponding 95 per cent confidence intervals (CI) and 95 per cent prediction intervals (PI). We included 25 trials on 1321 patients, with most comparing self-ligated (SL) and conventional brackets. Based on the meta-analyses, the duration of orthodontic treatment was on average 2.01 months longer among patients with SL brackets (95 per cent CI: 0.45 to 3.57). The 95 per cent PIs for a future trial indicated that the difference could be considerable (-1.46 to 5.47 months). Treatment characteristics, outcomes, and side-effects were clinically similar between SL and conventional brackets. For most bracket characteristics, evidence is insufficient. Some meta-analyses included trials with high risk of bias, but sensitivity analyses indicated robustness. Based on existing evidence, no clinical recommendation can be made regarding the bracket material or different ligation modules. For SL brackets, no conclusive benefits could be proven, while their use was associated with longer treatment durations.

  20. Insomnia From Drug Treatments: Evidence From Meta-analyses of Randomized Trials and Concordance With Prescribing Information.

    Science.gov (United States)

    Doufas, Anthony G; Panagiotou, Orestis A; Panousis, Periklis; Wong, Shane Shucheng; Ioannidis, John P A

    2017-01-01

    To determine whether drugs used to treat diverse conditions cause insomnia symptoms and whether their prescription information is concordant with this evidence. We conducted a survey of meta-analyses (Cochrane Database of Systematic Reviews) and comparisons with package inserts compiled in the Physicians' Desk Reference (PDR). We identified randomized controlled trials (RCTs) in which any drug had been evaluated vs placebo and sleep had been assessed. We collectively referred to insomnia-related outcomes as sleep disturbance. We also searched the PDR to identify any insomnia symptoms listed for drugs with RCT evidence available. Seventy-four Cochrane systematic reviews corresponding to 274 RCTs assessed 88 drugs in 27 different conditions, providing evidence on 109 drug-condition pairs. Of these 88 drugs, 5 decreased sleep problems and 19 increased sleep problems; 64 drugs had no nominally statistically significant effect on sleep. Acetylcholinesterase inhibitors, dopamine agonists, and selective serotonin reuptake inhibitors were the drug classes most importantly associated with sleep disturbance. Of 35 drugs that included disturbed sleep as an adverse effect in the PDR, only 14 had RCT evidence supporting such effect, and 2 had evidence of increasing and decreasing sleep problems in RCTs, although this was not shown in the PDR. We identified weak concordance between the PDR and RCTs (weighted κ=0.31; P<.001). The RCTs offer substantial evidence about the common effects of drugs on the risk of sleep disturbance; currently, prescription information only partially agrees with the available randomized evidence. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  1. Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

    Science.gov (United States)

    Kuiper, Jisca S; Zuidersma, Marij; Zuidema, Sytse U; Burgerhof, Johannes Gm; Stolk, Ronald P; Oude Voshaar, Richard C; Smidt, Nynke

    2016-08-01

    Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  2. Maternal Diabetes and the Risk of Autism Spectrum Disorders in the Offspring: A Systematic Review and Meta-Analysis

    Science.gov (United States)

    Xu, Guifeng; Jing, Jin; Bowers, Katherine; Liu, Buyun; Bao, Wei

    2014-01-01

    We performed a systematic literature search regarding maternal diabetes before and during pregnancy and the risk of autism spectrum disorders (ASD) in the offspring. Of the 178 potentially relevant articles, 12 articles including three cohort studies and nine case-control studies were included in the meta-analysis. Both the meta-analyses of cohort…

  3. D-cycloserine augmentation in behavioral therapy for obsessive-compulsive disorder: a meta-analysis

    Directory of Open Access Journals (Sweden)

    Xia J

    2015-04-01

    Full Text Available Jing Xia,1 Yanqiu Du,2 Jiyang Han,1 Guo Liu,1 Xumei Wang11Department of Psychiatry, Shengjing Hospital of China Medical University, Heping District Shenyang, Liaoning, People’s Republic of China; 2Department of Medicine, Shenyang Ninth People’s Hospital, Tiexi District, Shenyang, Liaoning, People’s Republic of ChinaObjective: To evaluate the overall effect of D-cycloserine (DCS augmentation on exposure and response prevention (ERP therapy for obsessive-compulsive disorder (OCD.Methods: Clinical studies on the effect of DCS augmentation on ERP therapy for OCD compared to placebo were included for meta analysis. The primary outcome was the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS. Meta-analyses were performed with a random-effect model or a fixed-effect model using the Cochrane Review Manager (RevMan, version 5.2 to calculate the odds ratio and the mean difference, with their corresponding 95% confidence intervals.Results: A total of six studies was included in the current meta-analyses, and their data were extracted. Among them, four were for analyses of DCS and Y-BOCS at midtreatment, six for analysis at posttreatment, and four at 3-month follow-up. Besides, three of the six eligible studies were included in the meta-analysis of the DCS and Clinical Global Impression – Severity Scale at posttreatment, and three in the meta-analysis of DCS and proportions of treatment responders and of subjects attaining clinical remission status criteria at posttreatment. Our meta-analyses do not reveal a significant effect of DCS augmentation in ERP therapy for OCD patients, except when measured at midtreatment. Compared to the placebo group, DCS augmentation did show a trend toward significantly lower/decreased Y-BOCS; when measured at posttreatment and in the subpopulation of DCS taken before some of the ERP sessions, DCS augmentation showed a trend toward significantly lower/decreased Y-BOCS.Conclusion: Our result suggested that with the careful

  4. MADAM - An open source meta-analysis toolbox for R and Bioconductor

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    Graber Armin

    2010-03-01

    Full Text Available Abstract Background Meta-analysis is a major theme in biomedical research. In the present paper we introduce a package for R and Bioconductor that provides useful tools for performing this type of work. One idea behind the development of MADAM was that many meta-analysis methods, which are available in R, are not able to use the capacities of parallel computing yet. In this first version, we implemented one meta-analysis method in such a parallel manner. Additionally, we provide tools for combining the results from a set of methods in an ensemble approach. Functionality for visualization of results is also provided. Results The presented package enables the carrying out of meta-analysis either by providing functions directly or by wrapping them to existing implementations. Overall, five different meta-analysis methods are now usable through MADAM, along with another three methods for combining the corresponding results. Visualizing the results is eased by three included functions. For developing and testing meta-analysis methods, a mock up data generator is integrated. Conclusions The use of MADAM enables a user to focus on one package, in turn enabling them to work with the same data types across a set of methods. By making use of the snow package, MADAM can be made compatible with an existing parallel computing infrastructure. MADAM is open source and freely available within CRAN http://cran.r-project.org.

  5. Hydropower externalities: A meta-analysis

    International Nuclear Information System (INIS)

    Mattmann, Matteo; Logar, Ivana; Brouwer, Roy

    2016-01-01

    This paper presents a meta-analysis of existing research related to the economic valuation of the external effects of hydropower. A database consisting of 81 observations derived from 29 studies valuing the non-market impacts of hydropower electricity generation is constructed with the main aim to quantify and explain the economic values for positive and negative hydropower externalities. Different meta-regression model specifications are used to test the robustness of significant determinants of non-market values, including different types of hydropower impacts. The explanatory and predictive power of the estimated models is relatively high. Whilst controlling for sample and study characteristics, we find significant evidence for public aversion towards deteriorations of landscape, vegetation and wildlife caused by hydropower projects. There is however only weak evidence of willingness to pay for mitigating these effects. The main positive externality of hydropower generation, the avoidance of greenhouse gas emission, positively influences welfare estimates when combined with the share of hydropower in national energy production. Sensitivity to scope is detected, but not linked to specific externalities or non-market valuation methods. - Highlights: • A global meta-analysis of valuation studies of hydropower externalities is presented. • Positive and negative externalities are distinguished. • Welfare losses due to environmental deteriorations outweigh gains of GHG reductions. • There is only weak evidence of public WTP for mitigating negative externalities. • The non-market values of hydropower externalities are sensitive to scope.

  6. A framework for the meta-analysis of Bland-Altman studies based on a limits of agreement approach.

    Science.gov (United States)

    Tipton, Elizabeth; Shuster, Jonathan

    2017-10-15

    Bland-Altman method comparison studies are common in the medical sciences and are used to compare a new measure to a gold-standard (often costlier or more invasive) measure. The distribution of these differences is summarized by two statistics, the 'bias' and standard deviation, and these measures are combined to provide estimates of the limits of agreement (LoA). When these LoA are within the bounds of clinically insignificant differences, the new non-invasive measure is preferred. Very often, multiple Bland-Altman studies have been conducted comparing the same two measures, and random-effects meta-analysis provides a means to pool these estimates. We provide a framework for the meta-analysis of Bland-Altman studies, including methods for estimating the LoA and measures of uncertainty (i.e., confidence intervals). Importantly, these LoA are likely to be wider than those typically reported in Bland-Altman meta-analyses. Frequently, Bland-Altman studies report results based on repeated measures designs but do not properly adjust for this design in the analysis. Meta-analyses of Bland-Altman studies frequently exclude these studies for this reason. We provide a meta-analytic approach that allows inclusion of estimates from these studies. This includes adjustments to the estimate of the standard deviation and a method for pooling the estimates based upon robust variance estimation. An example is included based on a previously published meta-analysis. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  7. The NOVA project: maximizing beam time efficiency through synergistic analyses of SRμCT data

    Science.gov (United States)

    Schmelzle, Sebastian; Heethoff, Michael; Heuveline, Vincent; Lösel, Philipp; Becker, Jürgen; Beckmann, Felix; Schluenzen, Frank; Hammel, Jörg U.; Kopmann, Andreas; Mexner, Wolfgang; Vogelgesang, Matthias; Jerome, Nicholas Tan; Betz, Oliver; Beutel, Rolf; Wipfler, Benjamin; Blanke, Alexander; Harzsch, Steffen; Hörnig, Marie; Baumbach, Tilo; van de Kamp, Thomas

    2017-09-01

    Beamtime and resulting SRμCT data are a valuable resource for researchers of a broad scientific community in life sciences. Most research groups, however, are only interested in a specific organ and use only a fraction of their data. The rest of the data usually remains untapped. By using a new collaborative approach, the NOVA project (Network for Online Visualization and synergistic Analysis of tomographic data) aims to demonstrate, that more efficient use of the valuable beam time is possible by coordinated research on different organ systems. The biological partners in the project cover different scientific aspects and thus serve as model community for the collaborative approach. As proof of principle, different aspects of insect head morphology will be investigated (e.g., biomechanics of the mouthparts, and neurobiology with the topology of sensory areas). This effort is accomplished by development of advanced analysis tools for the ever-increasing quantity of tomographic datasets. In the preceding project ASTOR, we already successfully demonstrated considerable progress in semi-automatic segmentation and classification of internal structures. Further improvement of these methods is essential for an efficient use of beam time and will be refined in the current NOVAproject. Significant enhancements are also planned at PETRA III beamline p05 to provide all possible contrast modalities in x-ray imaging optimized to biological samples, on the reconstruction algorithms, and the tools for subsequent analyses and management of the data. All improvements made on key technologies within this project will in the long-term be equally beneficial for all users of tomography instrumentations.

  8. Meta-Analyses of Association Between BRAFV600E Mutation and Clinicopathological Features of Papillary Thyroid Carcinoma

    Directory of Open Access Journals (Sweden)

    Qing Zhang

    2016-02-01

    Full Text Available Background/Aims: The function of BRAF V600E as a prognostic biomarker continues controversial by reason of conflicting results in the published articles. Methods: A systematical literature search for relevant articles was performed in PubMed, Cochrane Library, Google Scholar, Medline and Embase updated to August 5, 2015. The Chi-square test and I2 were employed to examine statistical heterogeneity. Pooled ORs with their corresponding 95% confidence intervals (95%CIs were calculated to assess the relationship between clinicopathological features and BRAFV600E mutation. Subgroup analyses by ethnicity were also performed to explore the potential sources of heterogeneity. Furthermore, publication bias was detected using the funnel plot and all statistical analyses were conducted by the software of R 3.12. Results: Of 25,241 cases with PTC, 15,290 (60.6% were positive for BRAF mutation and 9,951 (39.4% were tested negative for BRAF mutation. Negative status of BRAFV600E mutation negative was significantly associated with gender (OR = 0.90, 95%CI = 0.83-0.97 and concomitant hashimoto thyroiditis (OR = 0.53, 95%CI = 0.43-0.64. By contrast, positive status of BRAFV600E mutation was a significant predictor of multifocality (OR = 1.23; 95%CI = 1.14-1.32, extrathyroidal extension (OR = 2.23; 95%CI = 1.90-2.63, TNM stage (OR = 1.67; 95%CI = 1.53-1.81, lymph node metastasis (OR = 1.67; 95%CI = 1.45-1.93, vascular invasion (OR = 1.47; 95%CI = 1.22-1.79 and recurrence/persistence (OR = 2.33; 95%CI = 1.71-3.18. However, there was no significant association between BRAFV600E mutation and factors including age > 45 (OR = 0.98; 95%CI = 0.89-1.07, tumor size (OR = 0.84; 95%CI = 0.64-1.09 and distant metastasis (OR = 1.23; 95%CI = 0.67-2.27. Conclusion: This meta-analysis confirmed significant associations between BRAFV600E mutation and female gender, multifocality, ETE, LNM, TNM stage, concomitant hashimoto thyroiditis, vascular invasion and recurrence

  9. How Efficacious is Danshen (Salvia miltiorrhiza) Dripping Pill in Treating Angina Pectoris? Evidence Assessment for Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Jia, Yongliang; Leung, Siu-Wai

    2017-09-01

    More than 230 randomized controlled trials (RCTs) of danshen dripping pill (DSP) and isosorbide dinitrate (ISDN) in treating angina pectoris after the first preferred reporting items for systematic reviews and meta-analyses-compliant comprehensive meta-analysis were published in 2010. Other meta-analyses had flaws in study selection, statistical meta-analysis, and evidence assessment. This study completed the meta-analysis with an extensive assessment of the evidence. RCTs published from 1994 to 2016 on DSP and ISDN in treating angina pectoris for at least 4 weeks were included. The risk of bias (RoB) of included RCTs was assessed with the Cochrane's tool for assessing RoB. Meta-analyses based on a random-effects model were performed on two outcome measures: symptomatic (SYM) and electrocardiography (ECG) improvements. Subgroup analysis, sensitivity analysis, metaregression, and publication bias analysis were also conducted. The evidence strength was evaluated with the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) method. Among the included 109 RCTs with 11,973 participants, 49 RCTs and 5042 participants were new (after 2010). The RoB of included RCTs was high in randomization and blinding. Overall effect sizes in odds ratios for DSP over ISDN were 2.94 (95% confidence interval [CI]: 2.53-3.41) on SYM (n = 108) and 2.37 (95% CI: 2.08-2.69) by ECG (n = 81) with significant heterogeneities (I 2  = 41%, p < 0.0001 on SYM and I 2  = 44%, p < 0.0001 on ECG). Subgroup, sensitivity, and metaregression analyses showed consistent results without publication bias. However, the evidence strength was low in GRADE. The efficacy of DSP was still better than ISDN in treating angina pectoris, but the confidence decreased due to high RoB and heterogeneities.

  10. Can statistic adjustment of OR minimize the potential confounding bias for meta-analysis of case-control study? A secondary data analysis.

    Science.gov (United States)

    Liu, Tianyi; Nie, Xiaolu; Wu, Zehao; Zhang, Ying; Feng, Guoshuang; Cai, Siyu; Lv, Yaqi; Peng, Xiaoxia

    2017-12-29

    Different confounder adjustment strategies were used to estimate odds ratios (ORs) in case-control study, i.e. how many confounders original studies adjusted and what the variables are. This secondary data analysis is aimed to detect whether there are potential biases caused by difference of confounding factor adjustment strategies in case-control study, and whether such bias would impact the summary effect size of meta-analysis. We included all meta-analyses that focused on the association between breast cancer and passive smoking among non-smoking women, as well as each original case-control studies included in these meta-analyses. The relative deviations (RDs) of each original study were calculated to detect how magnitude the adjustment would impact the estimation of ORs, compared with crude ORs. At the same time, a scatter diagram was sketched to describe the distribution of adjusted ORs with different number of adjusted confounders. Substantial inconsistency existed in meta-analysis of case-control studies, which would influence the precision of the summary effect size. First, mixed unadjusted and adjusted ORs were used to combine individual OR in majority of meta-analysis. Second, original studies with different adjustment strategies of confounders were combined, i.e. the number of adjusted confounders and different factors being adjusted in each original study. Third, adjustment did not make the effect size of original studies trend to constringency, which suggested that model fitting might have failed to correct the systematic error caused by confounding. The heterogeneity of confounder adjustment strategies in case-control studies may lead to further bias for summary effect size in meta-analyses, especially for weak or medium associations so that the direction of causal inference would be even reversed. Therefore, further methodological researches are needed, referring to the assessment of confounder adjustment strategies, as well as how to take this kind

  11. MetaMetaDB: a database and analytic system for investigating microbial habitability.

    Directory of Open Access Journals (Sweden)

    Ching-chia Yang

    Full Text Available MetaMetaDB (http://mmdb.aori.u-tokyo.ac.jp/ is a database and analytic system for investigating microbial habitability, i.e., how a prokaryotic group can inhabit different environments. The interaction between prokaryotes and the environment is a key issue in microbiology because distinct prokaryotic communities maintain distinct ecosystems. Because 16S ribosomal RNA (rRNA sequences play pivotal roles in identifying prokaryotic species, a system that comprehensively links diverse environments to 16S rRNA sequences of the inhabitant prokaryotes is necessary for the systematic understanding of the microbial habitability. However, existing databases are biased to culturable prokaryotes and exhibit limitations in the comprehensiveness of the data because most prokaryotes are unculturable. Recently, metagenomic and 16S rRNA amplicon sequencing approaches have generated abundant 16S rRNA sequence data that encompass unculturable prokaryotes across diverse environments; however, these data are usually buried in large databases and are difficult to access. In this study, we developed MetaMetaDB (Meta-Metagenomic DataBase, which comprehensively and compactly covers 16S rRNA sequences retrieved from public datasets. Using MetaMetaDB, users can quickly generate hypotheses regarding the types of environments a prokaryotic group may be adapted to. We anticipate that MetaMetaDB will improve our understanding of the diversity and evolution of prokaryotes.

  12. MetaMetaDB: a database and analytic system for investigating microbial habitability.

    Science.gov (United States)

    Yang, Ching-chia; Iwasaki, Wataru

    2014-01-01

    MetaMetaDB (http://mmdb.aori.u-tokyo.ac.jp/) is a database and analytic system for investigating microbial habitability, i.e., how a prokaryotic group can inhabit different environments. The interaction between prokaryotes and the environment is a key issue in microbiology because distinct prokaryotic communities maintain distinct ecosystems. Because 16S ribosomal RNA (rRNA) sequences play pivotal roles in identifying prokaryotic species, a system that comprehensively links diverse environments to 16S rRNA sequences of the inhabitant prokaryotes is necessary for the systematic understanding of the microbial habitability. However, existing databases are biased to culturable prokaryotes and exhibit limitations in the comprehensiveness of the data because most prokaryotes are unculturable. Recently, metagenomic and 16S rRNA amplicon sequencing approaches have generated abundant 16S rRNA sequence data that encompass unculturable prokaryotes across diverse environments; however, these data are usually buried in large databases and are difficult to access. In this study, we developed MetaMetaDB (Meta-Metagenomic DataBase), which comprehensively and compactly covers 16S rRNA sequences retrieved from public datasets. Using MetaMetaDB, users can quickly generate hypotheses regarding the types of environments a prokaryotic group may be adapted to. We anticipate that MetaMetaDB will improve our understanding of the diversity and evolution of prokaryotes.

  13. Circulating Resistin Levels and Risk of Colorectal Cancer: A Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Gui Yang

    2016-01-01

    Full Text Available Objectives. Published data on resistin levels in patients with colorectal cancer (CRC were conflicting and heterogeneous. We conducted a meta-analysis of observational studies to examine the association of circulating resistin levels with carcinogenesis of the CRC. Methods. Potentially eligible studies published up to November 2015 were searched through MEDLINE, EMBASE, Science Citation Index Expanded database, CNKI, and WanFang database. The pooled weighted mean differences (WMDs with 95% confidence intervals (CIs calculated by fixed- or random-effect model were used to estimate the effects. Results. A total of 11 studies involving 965 patients were admitted in our meta-analysis. The pooled effects indicated that resistin levels were higher in CRC patients compared to healthy controls (WMD: 1.47 ng/mL; 95% CI: 0.78 to 2.16, with significant heterogeneity across the studies (I2=72%, p<0.0001. Subgroup analyses and sensitivity analyses revealed that study quality, design, sample type, and resistin assays may account for this heterogeneity. No publication bias was observed. Conclusions. Our meta-analysis suggests that increased circulating resistin levels are associated with greater risk of colorectal cancer. Given the limited number of available studies and significant heterogeneity, larger well-designed randomized studies are warranted.

  14. Memory and Obstructive Sleep Apnea: A Meta-Analysis

    Science.gov (United States)

    Wallace, Anna; Bucks, Romola S.

    2013-01-01

    Study Objectives: To examine episodic memory performance in individuals with obstructive sleep apnea (OSA). Design Meta-analysis was used to synthesize results from individual studies examining the impact of OSA on episodic memory performance. The performance of individuals with OSA was compared to healthy controls or normative data. Participants Forty-two studies were included, comprising 2,294 adults with untreated OSA and 1,364 healthy controls. Studies that recorded information about participants at baseline prior to treatment interventions were included in the analysis. Measurements Participants were assessed with tasks that included a measure of episodic memory: immediate recall, delayed recall, learning, and/or recognition memory. Results: The results of the meta-analyses provide evidence that individuals with OSA are significantly impaired when compared to healthy controls on verbal episodic memory (immediate recall, delayed recall, learning, and recognition) and visuo-spatial episodic memory (immediate and delayed recall), but not visual immediate recall or visuo-spatial learning. When patients were compared to norms, negative effects of OSA were found only in verbal immediate and delayed recall. Conclusions: This meta-analysis contributes to understanding of the nature of episodic memory deficits in individuals with OSA. Impairments to episodic memory are likely to affect the daily functioning of individuals with OSA. Citation Wallace A; Bucks RS. Memory and obstructive sleep apnea: a meta-analysis. SLEEP 2013;36(2):203-220. PMID:23372268

  15. Neurological Soft Signs in Schizophrenia: A Meta-analysis

    Science.gov (United States)

    Chan, Raymond C. K.; Xu, Ting; Heinrichs, R. Walter; Yu, Yue; Wang, Ya

    2010-01-01

    Background: Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups. Method: A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms. Results: A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%–10% of their variance with NSS. Conclusions: NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness. PMID:19377058

  16. Understanding new product project performance : A meta-analysis

    NARCIS (Netherlands)

    Commandeur, H.R.; Pattikawa, L.H.; Verwaal, E.

    2006-01-01

    Purpose: The purpose of this paper is to summarize the accumulated body of knowledge on the performance of new product projects and provide directions for further research. Design/methodology/approach: Using a refined classification of antecedents of new product project performance the research

  17. Clinical Effectiveness of Occupational Therapy in Mental Health: A Meta-Analysis.

    Science.gov (United States)

    Ikiugu, Moses N; Nissen, Ranelle M; Bellar, Cali; Maassen, Alexya; Van Peursem, Katlin

    The purpose of this study was to estimate the effectiveness of theory-based occupational therapy interventions in improving occupational performance and well-being among people with a mental health diagnosis. The meta-analysis included 11 randomized controlled trials with a total of 520 adult participants with a mental health diagnosis. Outcomes were occupational performance, well-being, or both. We conducted meta-analyses using Comprehensive Meta-Analysis software (Version 3.0) with occupational performance and well-being as the dependent variables. Results indicated a medium effect of intervention on improving occupational performance (mean Hedge's g = 0.50, Z = 4.05, p occupational therapy interventions may be effective in improving occupational performance and well-being among people with a mental health diagnosis and should be an integral part of rehabilitation services in mental health. Copyright © 2017 by the American Occupational Therapy Association, Inc.

  18. Autogenic training: a meta-analysis of clinical outcome studies.

    Science.gov (United States)

    Stetter, Friedhelm; Kupper, Sirko

    2002-03-01

    Autogenic training (AT) is a self-relaxation procedure by which a psychophysiological determined relaxation response is elicited. A meta-analysis was performed to evaluate the clinical effectiveness of AT. Seventy-three controlled outcome studies were found (published 1952-99). Sixty studies (35 randomized controlled trials [RCT]) qualified for inclusion in the meta-analysis. Medium-to-large effect sizes (ES) occurred for pre-post comparisons of disease-specific AT-effects, with the RCTs showing larger ES. When AT was compared to real control conditions, medium ES were found. Comparisons of AT versus other psychological treatment mostly resulted in no effects or small negative ES. This pattern of results was stable at follow-up. Unspecific AT-effects (i.e., effects on mood, cognitive performance, quality of life, and physiological variables) tended to be even larger than main effects. Separate meta-analyses for different disorders revealed a significant reduction of the heterogeneity of ES. Positive effects (medium range) of AT and of AT versus control in the meta-analysis of at least 3 studies were found for tension headache/migraine, mild-to-moderate essential hypertension, coronary heart disease, asthma bronchiale, somatoform pain disorder (unspecified type), Raynaud's disease, anxiety disorders, mild-to-moderate depression/dysthymia, and functional sleep disorders.

  19. Association of Helicobacter pylori infection with chronic atrophic gastritis: Meta-analyses according to type of disease definition.

    Science.gov (United States)

    Weck, Melanie N; Brenner, Hermann

    2008-08-15

    Helicobacter pylori is a major risk factor for chronic atrophic gastritis (CAG). A large variety of definitions of CAG have been used in epidemiologic studies in the past. The aim of this work was to systematically review and summarize estimates of the association between H. pylori infection and CAG according to the various definitions of CAG. Articles on the association between H. pylori infection and CAG published until July 2007 were identified. Separate meta-analyses were carried out for studies defining CAG based on gastroscopy with biopsy, serum pepsinogen I (PG I) only, the pepsinogen I/pepsinogen II ratio (PG I/PG II ratio) only, or a combination of PG I and the PG I/PG II ratio. Numbers of identified studies and summary odds ratios (OR) (95% confidence intervals) were as follows: gastroscopy with biopsy: n = 34, OR = 6.4 (4.0-10.1); PG I only: n = 13, OR = 0.9 (0.7-1.2); PG I/PG II ratio: n = 8, OR = 7.2 (3.1-16.8); combination of PG I and the PG I/PG II ratio: n = 20, OR = 5.7 (4.4-7.5). Studies with CAG definitions based on gastroscopy with biopsy or the PG I/PG II ratio (alone or in combination with PG I) yield similarly strong associations of H. pylori with CAG. The association is missed entirely in studies where CAG is defined by PG I only. (c) 2008 Wiley-Liss, Inc.

  20. Can simply answering research questions change behaviour? Systematic review and meta analyses of brief alcohol intervention trials.

    Directory of Open Access Journals (Sweden)

    Jim McCambridge

    Full Text Available Participant reports of their own behaviour are critical for the provision and evaluation of behavioural interventions. Recent developments in brief alcohol intervention trials provide an opportunity to evaluate longstanding concerns that answering questions on behaviour as part of research assessments may inadvertently influence it and produce bias. The study objective was to evaluate the size and nature of effects observed in randomized manipulations of the effects of answering questions on drinking behaviour in brief intervention trials.Multiple methods were used to identify primary studies. Between-group differences in total weekly alcohol consumption, quantity per drinking day and AUDIT scores were evaluated in random effects meta-analyses. Ten trials were included in this review, of which two did not provide findings for quantitative study, in which three outcomes were evaluated. Between-group differences were of the magnitude of 13.7 (-0.17 to 27.6 grams of alcohol per week (approximately 1.5 U.K. units or 1 standard U.S. drink and 1 point (0.1 to 1.9 in AUDIT score. There was no difference in quantity per drinking day.Answering questions on drinking in brief intervention trials appears to alter subsequent self-reported behaviour. This potentially generates bias by exposing non-intervention control groups to an integral component of the intervention. The effects of brief alcohol interventions may thus have been consistently under-estimated. These findings are relevant to evaluations of any interventions to alter behaviours which involve participant self-report.