A Meta-Analysis of Mathematics and Working Memory: Moderating Effects of Working Memory Domain, Type of Mathematics Skill, and Sample Characteristics

Science.gov (United States)

Peng, Peng; Namkung, Jessica; Barnes, Marcia; Sun, Congying

2016-01-01

The purpose of this meta-analysis was to determine the relation between mathematics and working memory (WM) and to identify possible moderators of this relation including domains of WM, types of mathematics skills, and sample type. A meta-analysis of 110 studies with 829 effect sizes found a significant medium correlation of mathematics and WM, r…

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...

Self-collected versus clinician-collected sampling for sexually transmitted infections: a systematic review and meta-analysis protocol.

Science.gov (United States)

Taylor, Darlene; Lunny, Carole; Wong, Tom; Gilbert, Mark; Li, Neville; Lester, Richard; Krajden, Mel; Hoang, Linda; Ogilvie, Gina

2013-10-10

Three meta-analyses and one systematic review have been conducted on the question of whether self-collected specimens are as accurate as clinician-collected specimens for STI screening. However, these reviews predate 2007 and did not analyze rectal or pharyngeal collection sites. Currently, there is no consensus on which sampling method is the most effective for the diagnosis of genital chlamydia (CT), gonorrhea (GC) or human papillomavirus (HPV) infection. Our meta-analysis aims to be comprehensive in that it will examine the evidence of whether self-collected vaginal, urine, pharyngeal and rectal specimens provide as accurate a clinical diagnosis as clinician-collected samples (reference standard). Eligible studies include both randomized and non-randomized controlled trials, pre- and post-test designs, and controlled observational studies. The databases that will be searched include the Cochrane Database of Systematic Reviews, Web of Science, Database of Abstracts of Reviews of Effects (DARE), EMBASE and PubMed/Medline. Data will be abstracted independently by two reviewers using a standardized pre-tested data abstraction form. Heterogeneity will be assessed using the Q2 test. Sensitivity and specificity estimates with 95% confidence intervals as well as negative and positive likelihood ratios will be pooled and weighted using random effects meta-analysis, if appropriate. A hierarchical summary receiver operating characteristics curve for self-collected specimens will be generated. This synthesis involves a meta-analysis of self-collected samples (urine, vaginal, pharyngeal and rectal swabs) versus clinician-collected samples for the diagnosis of CT, GC and HPV, the most prevalent STIs. Our systematic review will allow patients, clinicians and researchers to determine the diagnostic accuracy of specimens collected by patients compared to those collected by clinicians in the detection of chlamydia, gonorrhea and HPV.

Personality and Cognitive Decline in Older Adults: Data From a Longitudinal Sample and Meta-Analysis

Science.gov (United States)

Terracciano, Antonio; Stephan, Yannick; Sutin, Angelina R.

2016-01-01

Objectives: Personality traits are associated with risk of dementia; less is known about their association with the trajectory of cognitive functioning. This research examines the association between the 5 major dimensions of personality and cognitive function and decline in older adulthood and includes a meta-analysis of published studies. Method: Personality traits, objective and subjective memory, and cognitive status were collected in a large national sample (N = 13,987) with a 4-year follow-up period. For each trait, the meta-analysis pooled results from up to 5 prospective studies to examine personality and change in global cognition. Results: Higher Neuroticism was associated with worse performance on all cognitive measures and greater decline in memory, whereas higher Conscientiousness and Openness were associated with better memory performance concurrently and less decline over time. All traits were associated with subjective memory. Higher Conscientiousness and lower Extraversion were associated with better cognitive status and less decline. Although modest, these associations were generally larger than that of hypertension, diabetes, history of psychological treatment, obesity, smoking, and physical inactivity. The meta-analysis supported the association between Neuroticism and Conscientiousness and cognitive decline. Discussion: Personality is associated with cognitive decline in older adults, with effects comparable to established clinical and lifestyle risk factors. PMID:25583598

Conducting Meta-Analysis Using SAS

CERN Document Server

Arthur, Winfried; Huffcutt, Allen I; Arthur, Winfred

2001-01-01

Conducting Meta-Analysis Using SAS reviews the meta-analysis statistical procedure and shows the reader how to conduct one using SAS. It presents and illustrates the use of the PROC MEANS procedure in SAS to perform the data computations called for by the two most commonly used meta-analytic procedures, the Hunter & Schmidt and Glassian approaches. This book serves as both an operational guide and user's manual by describing and explaining the meta-analysis procedures and then presenting the appropriate SAS program code for computing the pertinent statistics. The practical, step-by-step instru

Causal Meta-Analysis : Methodology and Applications

NARCIS (Netherlands)

Bax, L.J.

2009-01-01

Meta-analysis is a statistical method to summarize research data from multiple studies in a quantitative manner. This dissertation addresses a number of methodological topics in causal meta-analysis and reports the development and validation of meta-analysis software. In the first (methodological)

metaCCA: summary statistics-based multivariate meta-analysis of genome-wide association studies using canonical correlation analysis.

Science.gov (United States)

Cichonska, Anna; Rousu, Juho; Marttinen, Pekka; Kangas, Antti J; Soininen, Pasi; Lehtimäki, Terho; Raitakari, Olli T; Järvelin, Marjo-Riitta; Salomaa, Veikko; Ala-Korpela, Mika; Ripatti, Samuli; Pirinen, Matti

2016-07-01

A dominant approach to genetic association studies is to perform univariate tests between genotype-phenotype pairs. However, analyzing related traits together increases statistical power, and certain complex associations become detectable only when several variants are tested jointly. Currently, modest sample sizes of individual cohorts, and restricted availability of individual-level genotype-phenotype data across the cohorts limit conducting multivariate tests. We introduce metaCCA, a computational framework for summary statistics-based analysis of a single or multiple studies that allows multivariate representation of both genotype and phenotype. It extends the statistical technique of canonical correlation analysis to the setting where original individual-level records are not available, and employs a covariance shrinkage algorithm to achieve robustness.Multivariate meta-analysis of two Finnish studies of nuclear magnetic resonance metabolomics by metaCCA, using standard univariate output from the program SNPTEST, shows an excellent agreement with the pooled individual-level analysis of original data. Motivated by strong multivariate signals in the lipid genes tested, we envision that multivariate association testing using metaCCA has a great potential to provide novel insights from already published summary statistics from high-throughput phenotyping technologies. Code is available at https://github.com/aalto-ics-kepaco anna.cichonska@helsinki.fi or matti.pirinen@helsinki.fi Supplementary data are available at Bioinformatics online. © The Author 2016. Published by Oxford University Press.

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

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.

Meta-analysis a structural equation modeling approach

CERN Document Server

Cheung, Mike W-L

2015-01-01

Presents a novel approach to conducting meta-analysis using structural equation modeling. Structural equation modeling (SEM) and meta-analysis are two powerful statistical methods in the educational, social, behavioral, and medical sciences. They are often treated as two unrelated topics in the literature. This book presents a unified framework on analyzing meta-analytic data within the SEM framework, and illustrates how to conduct meta-analysis using the metaSEM package in the R statistical environment. Meta-Analysis: A Structural Equation Modeling Approach begins by introducing the impo

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

Meta-analysis for evidence synthesis in plant pathology: an overview.

Science.gov (United States)

Madden, L V; Paul, P A

2011-01-01

Meta-analysis is the analysis of the results of multiple studies, which is typically performed in order to synthesize evidence from many possible sources in a formal probabilistic manner. In a simple sense, the outcome of each study becomes a single observation in the meta-analysis of all available studies. The methodology was developed originally in the social sciences by Smith, Glass, Rosenthal, Hunter, and Schmidt, based on earlier pioneering contributions in statistics by Fisher, Pearson, Yates, and Cochran, but this approach to research synthesis has now been embraced within many scientific disciplines. However, only a handful of articles have been published in plant pathology and related fields utilizing meta-analysis. After reviewing basic concepts and approaches, methods for estimating parameters and interpreting results are shown. The advantages of meta-analysis are presented in terms of prediction and risk analysis, and the high statistical power that can be achieved for detecting significant effects of treatments or significant relationships between variables. Based on power considerations, the fallacy of naïve counting of P values in a narrative review is demonstrated. Although there are many advantages to meta-analysis, results can be biased if the analysis is based on a nonrepresentative sample of study outcomes. Therefore, novel approaches for characterizing the upper bound on the bias are discussed, in order to show the robustness of meta-analysis to possible violation of assumptions.

OHBM 2017: Practical intensity based meta-analysis

OpenAIRE

Maumet, Camille

2017-01-01

"Practical intensity-based meta-analysis" slides from my talk in the OHBM 2017 educational talk on Neuroimaging meta-analysis.http://www.humanbrainmapping.org/files/2017/ED Courses/Neuroimaging Meta-Analysis.pdf

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.

Financial liberalization and economic growth : A meta-analysis

NARCIS (Netherlands)

Bumann, Silke; Hermes, Niels; Lensink, Robert

This study provides a systematic analysis of the empirical literature on the relationship between financial liberalization and economic growth by conducting a meta-analysis, based on 441 t-statistics reported in 60 empirical studies. We focus on explaining the heterogeneity of results in our sample

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.

MetaFIND: A feature analysis tool for metabolomics data

Directory of Open Access Journals (Sweden)

Cunningham Pádraig

2008-11-01

Full Text Available Abstract Background Metabolomics, or metabonomics, refers to the quantitative analysis of all metabolites present within a biological sample and is generally carried out using NMR spectroscopy or Mass Spectrometry. Such analysis produces a set of peaks, or features, indicative of the metabolic composition of the sample and may be used as a basis for sample classification. Feature selection may be employed to improve classification accuracy or aid model explanation by establishing a subset of class discriminating features. Factors such as experimental noise, choice of technique and threshold selection may adversely affect the set of selected features retrieved. Furthermore, the high dimensionality and multi-collinearity inherent within metabolomics data may exacerbate discrepancies between the set of features retrieved and those required to provide a complete explanation of metabolite signatures. Given these issues, the latter in particular, we present the MetaFIND application for 'post-feature selection' correlation analysis of metabolomics data. Results In our evaluation we show how MetaFIND may be used to elucidate metabolite signatures from the set of features selected by diverse techniques over two metabolomics datasets. Importantly, we also show how MetaFIND may augment standard feature selection and aid the discovery of additional significant features, including those which represent novel class discriminating metabolites. MetaFIND also supports the discovery of higher level metabolite correlations. Conclusion Standard feature selection techniques may fail to capture the full set of relevant features in the case of high dimensional, multi-collinear metabolomics data. We show that the MetaFIND 'post-feature selection' analysis tool may aid metabolite signature elucidation, feature discovery and inference of metabolic correlations.

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...

Meta-analysis: Problems with Russian Publications.

Science.gov (United States)

Verbitskaya, E V

2015-01-01

International Journals have built-in tools for saving citations to reference manager software. The majority of articles in Russian journals cannot be captured by citation management systems: they do not have special coding of articles descriptors.c. Some journals still have PDF files of the whole journal issue without dividing it into articles and do not provide any descriptors, making manual time-consuming input of information the only possibility. Moreover the context search of the article content is unavailable for search engines.2) The quality of research. This problem has been discussed for more than twenty years already. Still we have too many publications of poor quality of study design and statistical analysis. With the exception of pharmacological clinical tails, designed and supervised by international Pharma industry, many interventional studies, conducted in Russia, have methodological flaws inferring a high risk of bias:a. Absence of adequate control,b. No standard endpoints, duration of therapy and follow up,c. Absence of randomization and blinding,d. Low power of studies: sample sizes are calculated (if calculated at all) in such a way, that the main goal is to have as small sample size as possible. Very often statisticians have to solve the problem how to substantiate a small number of subjects, that sponsor could afford, instead of calculating the needed sample size to reach enough power.e. No standards of statistical analysis.f. Russian journals do not have standards for description and presentation of study results, in particular, results of statistical analysis (a reader even cannot see what is presented: standard deviation (SD) or standard error of the mean (SEM).We have a long standing experience in analysis of methodological and statistical quality of Russian biomedical publications and have found up to 80% publications with statistical and methodological errors and high risk of bias.In our practice, we had tried to perform two Meta-analyses for two local

Neurological Soft Signs in Schizophrenia: A Meta-analysis

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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

Dyadic Interracial Interactions: A Meta-Analysis

Science.gov (United States)

Toosi, Negin R.; Babbitt, Laura G.; Ambady, Nalini; Sommers, Samuel R.

2012-01-01

This meta-analysis examined over 40 years of research on interracial interactions by exploring 4 types of outcomes: explicit attitudes toward interaction partners, participants' self-reports of their own emotional state, nonverbal or observed behavior, and objective measures of performance. Data were collected from 108 samples (N = 12,463)…

Network meta-analysis: an introduction for pharmacists.

Science.gov (United States)

Xu, Yina; Amiche, Mohamed Amine; Tadrous, Mina

2018-05-21

Network meta-analysis is a new tool used to summarize and compare studies for multiple interventions, irrespective of whether these interventions have been directly evaluated against each other. Network meta-analysis is quickly becoming the standard in conducting therapeutic reviews and clinical guideline development. However, little guidance is available to help pharmacists review network meta-analysis studies in their practice. Major institutions such as the Cochrane Collaboration, Agency for Healthcare Research and Quality, Canadian Agency for Drugs and Technologies in Health, and National Institute for Health and Care Excellence Decision Support Unit have endorsed utilizing network meta-analysis to establish therapeutic evidence and inform decision making. Our objective is to introduce this novel technique to pharmacy practitioners, and highlight key assumptions behind network meta-analysis studies.

Quality of Life in Autism across the Lifespan: A Meta-Analysis

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van Heijst, Barbara F. C.; Geurts, Hilde M.

2015-01-01

Autism is a lifelong neurodevelopmental disorder, with a known impact on quality of life. Yet the developmental trajectory of quality of life is not well understood. First, the effect of age on quality of life was studied with a meta-analysis. Our meta-analysis included 10 studies (published between 2004 and 2012) with a combined sample size of…

Comparison of diagnostic efficacy between CLE, tissue sampling, and CLE combined with tissue sampling for undetermined pancreaticobiliary strictures: a meta-analysis.

Science.gov (United States)

Gao, Ya-Dong; Qu, Ya-Wei; Liu, Hai-Feng

2018-04-01

The accurate diagnosis of undetermined pancreaticobiliary strictures remains challenging. Current ERCP-guided tissue sampling methods are of low sensitivity. Confocal laser endomicroscopy (CLE) is a new procedure and allows real optical biopsies that may improve the diagnosis of undetermined pancreaticobiliary strictures. The aim of this meta-analysis was to determine the diagnostic yield of CLE, tissue sampling, and CLE combined with tissue sampling for undetermined pancreaticobiliary strictures. Pubmed, Embase, and the Cochrane Library database were reviewed for relevant studies. Pooled estimates of sensitivity and specificity with 95% confidence intervals (CIs) were calculated using the random-effects meta-analysis model. The summary receiver-operating characteristic (SROC) curve was constructed, and the area under the receiver operating characteristic curve (AUC) was calculated. Twelve studies involving 591 patients were enrolled in our analysis. The overall sensitivity and the specificity estimate of CLE for discriminating benign and malignant pancreaticobiliary strictures were 87% (95%CI, 83-91%) and 76% (95%CI, 70-81%), respectively. The AUC to assess the diagnostic efficacy was 0.8705. For tissue sampling, the overall sensitivity and the specificity estimate were 64% (95%CI, 57-70%) and 94% (95%CI, 90-97%), respectively. The AUC to assess the diagnostic efficacy was 0.8040. A combination of both methods increased the sensitivity (93%; 95%CI, 88-96%) with a specificity of 82% (95%CI, 74-89%). The AUC to assess the diagnostic efficacy was 0.9377. There was no publication bias by Deeks' Funnel Plot with p = .936. Compared with tissue sampling, CLE may increase the sensitivity for the diagnosis of malignant pancreaticobiliary strictures. A combination of both can effectively diagnose malignant pancreaticobiliary strictures.

MetaEasy: A Meta-Analysis Add-In for Microsoft Excel

Directory of Open Access Journals (Sweden)

Evangelos Kontopantelis

2009-04-01

Full Text Available Meta-analysis is a statistical methodology that combines or integrates the results ofseveral independent clinical trials considered by the analyst to be `combinable' (Huque1988. However, completeness and user-friendliness are uncommon both in specialisedmeta-analysis software packages and in mainstream statistical packages that have to relyon user-written commands. We implemented the meta-analysis methodology in an Mi-crosoft Excel add-in which is freely available and incorporates more meta-analysis models(including the iterative maximum likelihood and prole likelihood than are usually avail-able, while paying particular attention to the user-friendliness of the package.

The potential for meta-analysis to support decision analysis in ecology.

Science.gov (United States)

Mengersen, Kerrie; MacNeil, M Aaron; Caley, M Julian

2015-06-01

Meta-analysis and decision analysis are underpinned by well-developed methods that are commonly applied to a variety of problems and disciplines. While these two fields have been closely linked in some disciplines such as medicine, comparatively little attention has been paid to the potential benefits of linking them in ecology, despite reasonable expectations that benefits would be derived from doing so. Meta-analysis combines information from multiple studies to provide more accurate parameter estimates and to reduce the uncertainty surrounding them. Decision analysis involves selecting among alternative choices using statistical information that helps to shed light on the uncertainties involved. By linking meta-analysis to decision analysis, improved decisions can be made, with quantification of the costs and benefits of alternate decisions supported by a greater density of information. Here, we briefly review concepts of both meta-analysis and decision analysis, illustrating the natural linkage between them and the benefits from explicitly linking one to the other. We discuss some examples in which this linkage has been exploited in the medical arena and how improvements in precision and reduction of structural uncertainty inherent in a meta-analysis can provide substantive improvements to decision analysis outcomes by reducing uncertainty in expected loss and maximising information from across studies. We then argue that these significant benefits could be translated to ecology, in particular to the problem of making optimal ecological decisions in the face of uncertainty. Copyright © 2013 John Wiley & Sons, Ltd.

Meta-Analysis at Middle Age: A Personal History

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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…

Meta-analysis of SNPs involved in variance heterogeneity using Levene's test for equal variances

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Deng, Wei Q; Asma, Senay; Paré, Guillaume

2014-01-01

Meta-analysis is a commonly used approach to increase the sample size for genome-wide association searches when individual studies are otherwise underpowered. Here, we present a meta-analysis procedure to estimate the heterogeneity of the quantitative trait variance attributable to genetic variants using Levene's test without needing to exchange individual-level data. The meta-analysis of Levene's test offers the opportunity to combine the considerable sample size of a genome-wide meta-analysis to identify the genetic basis of phenotypic variability and to prioritize single-nucleotide polymorphisms (SNPs) for gene–gene and gene–environment interactions. The use of Levene's test has several advantages, including robustness to departure from the normality assumption, freedom from the influence of the main effects of SNPs, and no assumption of an additive genetic model. We conducted a meta-analysis of the log-transformed body mass index of 5892 individuals and identified a variant with a highly suggestive Levene's test P-value of 4.28E-06 near the NEGR1 locus known to be associated with extreme obesity. PMID:23921533

Systematic mediastinal lymphadenectomy or mediastinal lymph node sampling in patients with pathological stage I NSCLC: a meta-analysis.

Science.gov (United States)

Dong, Siyuan; Du, Jiang; Li, Wenya; Zhang, Shuguang; Zhong, Xinwen; Zhang, Lin

2015-02-01

To evaluate the evidence comparing systematic mediastinal lymphadenectomy (SML) and mediastinal lymph node sampling (MLS) in the treatment of pathological stage I NSCLC using meta-analytical techniques. A literature search was undertaken until January 2014 to identify the comparative studies evaluating 1-, 3-, and 5-year survival rates. The pooled odds ratios (OR) and the 95 % confidence intervals (95 % CI) were calculated with either the fixed or random effect models. One RCT study and four retrospective studies were included in our meta-analysis. These studies included a total of 711 patients: 317 treated with SML, and 394 treated with MLS. The SML and the MLS did not demonstrate a significant difference in the 1-year survival rate. There were significant statistical differences between the 3-year (P = 0.03) and 5-year survival rates (P = 0.004), which favored SML. This meta-analysis suggests that in pathological stage I NSCLC, the MLS can get the similar outcome to the SML in terms of 1-year survival rate. However, the SML is superior to MLS in terms of 3- and 5-year survival rates.

Digital Simulation-Based Training: A Meta-Analysis

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Gegenfurtner, Andreas; Quesada-Pallarès, Carla; Knogler, Maximilian

2014-01-01

This study examines how design characteristics in digital simulation-based learning environments moderate self-efficacy and transfer of learning. Drawing on social cognitive theory and the cognitive theory of multimedia learning, the meta-analysis psychometrically cumulated k?=?15 studies of 25 years of research with a total sample size of…

Longitudinal analysis of meta-analysis literatures in the database of ISI Web of Science.

Science.gov (United States)

Zhu, Changtai; Jiang, Ting; Cao, Hao; Sun, Wenguang; Chen, Zhong; Liu, Jinming

2015-01-01

The meta-analysis is regarded as an important evidence for making scientific decision. The database of ISI Web of Science collected a great number of high quality literatures including meta-analysis literatures. However, it is significant to understand the general characteristics of meta-analysis literatures to outline the perspective of meta-analysis. In this present study, we summarized and clarified some features on these literatures in the database of ISI Web of Science. We retrieved the meta-analysis literatures in the database of ISI Web of Science including SCI-E, SSCI, A&HCI, CPCI-S, CPCI-SSH, CCR-E, and IC. The annual growth rate, literature category, language, funding, index citation, agencies and countries/territories of the meta-analysis literatures were analyzed, respectively. A total of 95,719 records, which account for 0.38% (99% CI: 0.38%-0.39%) of all literatures, were found in the database. From 1997 to 2012, the annual growth rate of meta-analysis literatures was 18.18%. The literatures involved in many categories, languages, fundings, citations, publication agencies, and countries/territories. Interestingly, the index citation frequencies of the meta-analysis were significantly higher than that of other type literatures such as multi-centre study, randomize controlled trial, cohort study, case control study, and cases report (Panalysis has been becoming more and more prominent in recent years. In future, in order to promote the validity of meta-analysis, the CONSORT and PRISMA standard should be continuously popularized in the field of evidence-based medicine.

dbMDEGA: a database for meta-analysis of differentially expressed genes in autism spectrum disorder.

Science.gov (United States)

Zhang, Shuyun; Deng, Libin; Jia, Qiyue; Huang, Shaoting; Gu, Junwang; Zhou, Fankun; Gao, Meng; Sun, Xinyi; Feng, Chang; Fan, Guangqin

2017-11-16

Autism spectrum disorders (ASD) are hereditary, heterogeneous and biologically complex neurodevelopmental disorders. Individual studies on gene expression in ASD cannot provide clear consensus conclusions. Therefore, a systematic review to synthesize the current findings from brain tissues and a search tool to share the meta-analysis results are urgently needed. Here, we conducted a meta-analysis of brain gene expression profiles in the current reported human ASD expression datasets (with 84 frozen male cortex samples, 17 female cortex samples, 32 cerebellum samples and 4 formalin fixed samples) and knock-out mouse ASD model expression datasets (with 80 collective brain samples). Then, we applied R language software and developed an interactive shared and updated database (dbMDEGA) displaying the results of meta-analysis of data from ASD studies regarding differentially expressed genes (DEGs) in the brain. This database, dbMDEGA ( https://dbmdega.shinyapps.io/dbMDEGA/ ), is a publicly available web-portal for manual annotation and visualization of DEGs in the brain from data from ASD studies. This database uniquely presents meta-analysis values and homologous forest plots of DEGs in brain tissues. Gene entries are annotated with meta-values, statistical values and forest plots of DEGs in brain samples. This database aims to provide searchable meta-analysis results based on the current reported brain gene expression datasets of ASD to help detect candidate genes underlying this disorder. This new analytical tool may provide valuable assistance in the discovery of DEGs and the elucidation of the molecular pathogenicity of ASD. This database model may be replicated to study other disorders.

Bayesian Meta-Analysis of Coefficient Alpha

Science.gov (United States)

Brannick, Michael T.; Zhang, Nanhua

2013-01-01

The current paper describes and illustrates a Bayesian approach to the meta-analysis of coefficient alpha. Alpha is the most commonly used estimate of the reliability or consistency (freedom from measurement error) for educational and psychological measures. The conventional approach to meta-analysis uses inverse variance weights to combine…

A resampling-based meta-analysis for detection of differential gene expression in breast cancer

International Nuclear Information System (INIS)

Gur-Dedeoglu, Bala; Konu, Ozlen; Kir, Serkan; Ozturk, Ahmet Rasit; Bozkurt, Betul; Ergul, Gulusan; Yulug, Isik G

2008-01-01

Accuracy in the diagnosis of breast cancer and classification of cancer subtypes has improved over the years with the development of well-established immunohistopathological criteria. More recently, diagnostic gene-sets at the mRNA expression level have been tested as better predictors of disease state. However, breast cancer is heterogeneous in nature; thus extraction of differentially expressed gene-sets that stably distinguish normal tissue from various pathologies poses challenges. Meta-analysis of high-throughput expression data using a collection of statistical methodologies leads to the identification of robust tumor gene expression signatures. A resampling-based meta-analysis strategy, which involves the use of resampling and application of distribution statistics in combination to assess the degree of significance in differential expression between sample classes, was developed. Two independent microarray datasets that contain normal breast, invasive ductal carcinoma (IDC), and invasive lobular carcinoma (ILC) samples were used for the meta-analysis. Expression of the genes, selected from the gene list for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes were tested on 10 independent primary IDC samples and matched non-tumor controls by real-time qRT-PCR. Other existing breast cancer microarray datasets were used in support of the resampling-based meta-analysis. The two independent microarray studies were found to be comparable, although differing in their experimental methodologies (Pearson correlation coefficient, R = 0.9389 and R = 0.8465 for ductal and lobular samples, respectively). The resampling-based meta-analysis has led to the identification of a highly stable set of genes for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes. The expression results of the selected genes obtained through real-time qRT-PCR supported the meta-analysis results. The

A resampling-based meta-analysis for detection of differential gene expression in breast cancer

Directory of Open Access Journals (Sweden)

Ergul Gulusan

2008-12-01

Full Text Available Abstract Background Accuracy in the diagnosis of breast cancer and classification of cancer subtypes has improved over the years with the development of well-established immunohistopathological criteria. More recently, diagnostic gene-sets at the mRNA expression level have been tested as better predictors of disease state. However, breast cancer is heterogeneous in nature; thus extraction of differentially expressed gene-sets that stably distinguish normal tissue from various pathologies poses challenges. Meta-analysis of high-throughput expression data using a collection of statistical methodologies leads to the identification of robust tumor gene expression signatures. Methods A resampling-based meta-analysis strategy, which involves the use of resampling and application of distribution statistics in combination to assess the degree of significance in differential expression between sample classes, was developed. Two independent microarray datasets that contain normal breast, invasive ductal carcinoma (IDC, and invasive lobular carcinoma (ILC samples were used for the meta-analysis. Expression of the genes, selected from the gene list for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes were tested on 10 independent primary IDC samples and matched non-tumor controls by real-time qRT-PCR. Other existing breast cancer microarray datasets were used in support of the resampling-based meta-analysis. Results The two independent microarray studies were found to be comparable, although differing in their experimental methodologies (Pearson correlation coefficient, R = 0.9389 and R = 0.8465 for ductal and lobular samples, respectively. The resampling-based meta-analysis has led to the identification of a highly stable set of genes for classification of normal breast samples and breast tumors encompassing both the ILC and IDC subtypes. The expression results of the selected genes obtained through real

Meta-Analysis for Primary and Secondary Data Analysis: The Super-Experiment Metaphor.

Science.gov (United States)

Jackson, Sally

1991-01-01

Considers the relation between meta-analysis statistics and analysis of variance statistics. Discusses advantages and disadvantages as a primary data analysis tool. Argues that the two approaches are partial paraphrases of one another. Advocates an integrative approach that introduces the best of meta-analytic thinking into primary analysis…

Trial Sequential Methods for Meta-Analysis

Science.gov (United States)

Kulinskaya, Elena; Wood, John

2014-01-01

Statistical methods for sequential meta-analysis have applications also for the design of new trials. Existing methods are based on group sequential methods developed for single trials and start with the calculation of a required information size. This works satisfactorily within the framework of fixed effects meta-analysis, but conceptual…

Formalizing the definition of meta-analysis in Molecular Ecology.

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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.

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

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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.

Meta-Analysis in Stata Using Gllamm

Science.gov (United States)

Bagos, Pantelis G.

2015-01-01

There are several user-written programs for performing meta-analysis in Stata (Stata Statistical Software: College Station, TX: Stata Corp LP). These include metan, metareg, mvmeta, and glst. However, there are several cases for which these programs do not suffice. For instance, there is no software for performing univariate meta-analysis with…

Self-Concept and Academic Achievement: A Meta-Analysis of Longitudinal Relations

Science.gov (United States)

Huang, Chiungjung

2011-01-01

The relation between self-concept and academic achievement was examined in 39 independent and longitudinal samples through the integration of meta-analysis and path analysis procedures. For relations with more than 3 independent samples, the mean observed correlations ranged from 0.20 to 0.27 between prior self-concept and subsequent academic…

a meta-analysis

Indian Academy of Sciences (India)

Chrissa G. Tsiara

2018-03-13

Mar 13, 2018 ... a meta-analysis of case–control studies was conducted. Univariate and ...... recent hepatitis C virus: potential benefit for ribavirin use in. HCV/HIV ... C/G polymorphism in breast pathologies and in HIV-infected patients.

Natural disasters and economic growth: A meta-analysis

NARCIS (Netherlands)

Klomp, J.G.; Valckx, K.

2014-01-01

Using more than 750 estimates, we perform a meta-regression analysis of studies examining the relationship between economic growth per capita and natural disasters. The studies considered are very different with respect to the type of disasters considered, the sample of countries and time periods

The global prevalence and correlates of skin bleaching: a meta-analysis and meta-regression analysis.

Science.gov (United States)

Sagoe, Dominic; Pallesen, Ståle; Dlova, Ncoza C; Lartey, Margaret; Ezzedine, Khaled; Dadzie, Ophelia

2018-06-11

To estimate and investigate the global lifetime prevalence and correlates of skin bleaching. A meta-analysis and meta-regression analysis was performed based on a systematic and comprehensive literature search conducted in Google Scholar, ISI Web of Science, ProQuest, PsycNET, PubMed, and other relevant websites and reference lists. A total of 68 studies (67,665 participants) providing original data on the lifetime prevalence of skin bleaching were included. Publication bias was corrected using the trim and fill procedure. The pooled (imputed) lifetime prevalence of skin bleaching was 27.7% (95% CI: 19.6-37.5, I 2  = 99.6, P < 0.01). The highest significant prevalences were associated with: males (28.0%), topical corticosteroid use (51.8%), Africa (27.1%), persons aged ≤30 years (55.9%), individuals with only primary school education (31.6%), urban or semiurban residents (74.9%), patients (21.3%), data from 2010-2017 (26.8%), dermatological evaluation and testing-based assessment (24.9%), random sampling methods (29.2%), and moderate quality studies (32.3%). The proportion of females in study samples was significantly related to skin bleaching prevalence. Despite some limitations, our results indicate that the practice of skin bleaching is a serious global public health issue that should be addressed through appropriate public health interventions. © 2018 The International Society of Dermatology.

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

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.

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.

Dividend Policy and Corporate Value (A Meta-Analysis

Directory of Open Access Journals (Sweden)

Tifani Titah Dwi Tyastari

2017-07-01

Full Text Available This study aimed to understand the effect of dividend policy on corporate value, as well as to examine and analyze the variation of result study on corporate value in Indonesia.Dividend Signaling Model was the grand theory used to explain the effect of dividend policy on corporate value. This study used meta-analysis approach with the sample were 70 researches in Indonesia, both the published and unpublished in 2007-2015. The result of this study, meta-analysis strengthens the findings of the previous study which stated that the dividend policy could increase the corporate value. The differences of the previous studies were due to the presence of moderation effect from the measurement model of corporate value and dividend corporate.

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.

Multivariate Methods for Meta-Analysis of Genetic Association Studies.

Science.gov (United States)

Dimou, Niki L; Pantavou, Katerina G; Braliou, Georgia G; Bagos, Pantelis G

2018-01-01

Multivariate meta-analysis of genetic association studies and genome-wide association studies has received a remarkable attention as it improves the precision of the analysis. Here, we review, summarize and present in a unified framework methods for multivariate meta-analysis of genetic association studies and genome-wide association studies. Starting with the statistical methods used for robust analysis and genetic model selection, we present in brief univariate methods for meta-analysis and we then scrutinize multivariate methodologies. Multivariate models of meta-analysis for a single gene-disease association studies, including models for haplotype association studies, multiple linked polymorphisms and multiple outcomes are discussed. The popular Mendelian randomization approach and special cases of meta-analysis addressing issues such as the assumption of the mode of inheritance, deviation from Hardy-Weinberg Equilibrium and gene-environment interactions are also presented. All available methods are enriched with practical applications and methodologies that could be developed in the future are discussed. Links for all available software implementing multivariate meta-analysis methods are also provided.

Achievement Goals and Achievement Emotions: A Meta-Analysis

Science.gov (United States)

Huang, Chiungjung

2011-01-01

This meta-analysis synthesized 93 independent samples (N = 30,003) in 77 studies that reported in 78 articles examining correlations between achievement goals and achievement emotions. Achievement goals were meaningfully associated with different achievement emotions. The correlations of mastery and mastery approach goals with positive achievement…

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

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:.

Moyer's method of mixed dentition analysis: a meta-analysis ...

African Journals Online (AJOL)

The applicability of tables derived from the data Moyer used to other ethnic groups has ... This implies that Moyer's method of prediction may have population variations. ... Key Words: meta-analysis, mixed dentition analysis, Moyer's method

The impact of pneumatic tube system on routine laboratory parameters: a systematic review and meta-analysis.

Science.gov (United States)

Kapoula, Georgia V; Kontou, Panagiota I; Bagos, Pantelis G

2017-10-26

Pneumatic tube system (PTS) is a widely used method of transporting blood samples in hospitals. The aim of this study was to evaluate the effects of the PTS transport in certain routine laboratory parameters as it has been implicated with hemolysis. A systematic review and a meta-analysis were conducted. PubMed and Scopus databases were searched (up until November 2016) to identify prospective studies evaluating the impact of PTS transport in hematological, biochemical and coagulation measurements. The random-effects model was used in the meta-analysis utilizing the mean difference (MD). Heterogeneity was quantitatively assessed using the Cohran's Q and the I2 index. Subgroup analysis, meta-regression analysis, sensitivity analysis, cumulative meta-analysis and assessment of publication bias were performed for all outcomes. From a total of 282 studies identified by the searching procedure, 24 were finally included in the meta-analysis. The meta-analysis yielded statistically significant results for potassium (K) [MD=0.04 mmol/L; 95% confidence interval (CI)=0.015-0.065; p=0.002], lactate dehydrogenase (LDH) (MD=10.343 U/L; 95% CI=6.132-14.554; panalysis and random-effects meta-regression analysis according to the speed and distance of the samples traveled via the PTS revealed that there is relation between the rate and the distance of PTS with the measurements of K, LDH, white blood cells and red blood cells. This meta-analysis suggests that PTS may be associated with alterations in K, LDH and AST measurements. Although these findings may not have any significant clinical effect on laboratory results, it is wise that each hospital validates their PTS.

Meta-analysis in clinical trials revisited.

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DerSimonian, Rebecca; Laird, Nan

2015-11-01

In this paper, we revisit a 1986 article we published in this Journal, Meta-Analysis in Clinical Trials, where we introduced a random-effects model to summarize the evidence about treatment efficacy from a number of related clinical trials. Because of its simplicity and ease of implementation, our approach has been widely used (with more than 12,000 citations to date) and the "DerSimonian and Laird method" is now often referred to as the 'standard approach' or a 'popular' method for meta-analysis in medical and clinical research. The method is especially useful for providing an overall effect estimate and for characterizing the heterogeneity of effects across a series of studies. Here, we review the background that led to the original 1986 article, briefly describe the random-effects approach for meta-analysis, explore its use in various settings and trends over time and recommend a refinement to the method using a robust variance estimator for testing overall effect. We conclude with a discussion of repurposing the method for Big Data meta-analysis and Genome Wide Association Studies for studying the importance of genetic variants in complex diseases. Published by Elsevier Inc.

Procedure-related risk of miscarriage following amniocentesis and chorionic villus sampling: a systematic review and meta-analysis.

Science.gov (United States)

Akolekar, R; Beta, J; Picciarelli, G; Ogilvie, C; D'Antonio, F

2015-01-01

To estimate procedure-related risks of miscarriage following amniocentesis and chorionic villus sampling (CVS) based on a systematic review of the literature and a meta-analysis. A search of MEDLINE, EMBASE, CINHAL and The Cochrane Library (2000-2014) was performed to review relevant citations reporting procedure-related complications of amniocentesis and CVS. Only studies reporting data on more than 1000 procedures were included in this review to minimize the effect of bias from smaller studies. Heterogeneity between studies was estimated using Cochran's Q, the I(2) statistic and Egger bias. Meta-analysis of proportions was used to derive weighted pooled estimates for the risk of miscarriage before 24 weeks' gestation. Incidence-rate difference meta-analysis was used to estimate pooled procedure-related risks. The weighted pooled risks of miscarriage following invasive procedures were estimated from analysis of controlled studies including 324 losses in 42 716 women who underwent amniocentesis and 207 losses in 8899 women who underwent CVS. The risk of miscarriage prior to 24 weeks in women who underwent amniocentesis and CVS was 0.81% (95% CI, 0.58-1.08%) and 2.18% (95% CI, 1.61-2.82%), respectively. The background rates of miscarriage in women from the control group that did not undergo any procedures were 0.67% (95% CI, 0.46-0.91%) for amniocentesis and 1.79% (95% CI, 0.61-3.58%) for CVS. The weighted pooled procedure-related risks of miscarriage for amniocentesis and CVS were 0.11% (95% CI, -0.04 to 0.26%) and 0.22% (95% CI, -0.71 to 1.16%), respectively. The procedure-related risks of miscarriage following amniocentesis and CVS are much lower than are currently quoted. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.

A random effects meta-analysis model with Box-Cox transformation.

Science.gov (United States)

Yamaguchi, Yusuke; Maruo, Kazushi; Partlett, Christopher; Riley, Richard D

2017-07-19

In a random effects meta-analysis model, true treatment effects for each study are routinely assumed to follow a normal distribution. However, normality is a restrictive assumption and the misspecification of the random effects distribution may result in a misleading estimate of overall mean for the treatment effect, an inappropriate quantification of heterogeneity across studies and a wrongly symmetric prediction interval. We focus on problems caused by an inappropriate normality assumption of the random effects distribution, and propose a novel random effects meta-analysis model where a Box-Cox transformation is applied to the observed treatment effect estimates. The proposed model aims to normalise an overall distribution of observed treatment effect estimates, which is sum of the within-study sampling distributions and the random effects distribution. When sampling distributions are approximately normal, non-normality in the overall distribution will be mainly due to the random effects distribution, especially when the between-study variation is large relative to the within-study variation. The Box-Cox transformation addresses this flexibly according to the observed departure from normality. We use a Bayesian approach for estimating parameters in the proposed model, and suggest summarising the meta-analysis results by an overall median, an interquartile range and a prediction interval. The model can be applied for any kind of variables once the treatment effect estimate is defined from the variable. A simulation study suggested that when the overall distribution of treatment effect estimates are skewed, the overall mean and conventional I 2 from the normal random effects model could be inappropriate summaries, and the proposed model helped reduce this issue. We illustrated the proposed model using two examples, which revealed some important differences on summary results, heterogeneity measures and prediction intervals from the normal random effects model. The

A random effects meta-analysis model with Box-Cox transformation

Directory of Open Access Journals (Sweden)

Yusuke Yamaguchi

2017-07-01

Full Text Available Abstract Background In a random effects meta-analysis model, true treatment effects for each study are routinely assumed to follow a normal distribution. However, normality is a restrictive assumption and the misspecification of the random effects distribution may result in a misleading estimate of overall mean for the treatment effect, an inappropriate quantification of heterogeneity across studies and a wrongly symmetric prediction interval. Methods We focus on problems caused by an inappropriate normality assumption of the random effects distribution, and propose a novel random effects meta-analysis model where a Box-Cox transformation is applied to the observed treatment effect estimates. The proposed model aims to normalise an overall distribution of observed treatment effect estimates, which is sum of the within-study sampling distributions and the random effects distribution. When sampling distributions are approximately normal, non-normality in the overall distribution will be mainly due to the random effects distribution, especially when the between-study variation is large relative to the within-study variation. The Box-Cox transformation addresses this flexibly according to the observed departure from normality. We use a Bayesian approach for estimating parameters in the proposed model, and suggest summarising the meta-analysis results by an overall median, an interquartile range and a prediction interval. The model can be applied for any kind of variables once the treatment effect estimate is defined from the variable. Results A simulation study suggested that when the overall distribution of treatment effect estimates are skewed, the overall mean and conventional I 2 from the normal random effects model could be inappropriate summaries, and the proposed model helped reduce this issue. We illustrated the proposed model using two examples, which revealed some important differences on summary results, heterogeneity measures and

DNA adducts and cancer risk in prospective studies: a pooled analysis and a meta-analysis

DEFF Research Database (Denmark)

Veglia, Fabrizio; Loft, Steffen; Matullo, Giuseppe

2008-01-01

in which bulky DNA adducts have been measured in blood samples collected from healthy subjects (N = 1947; average follow-up 51-137 months). In addition, we have performed a meta-analysis by identifying all articles on the same subject published up to the end of 2006, including case-control studies......). The association was evident only in current smokers and was absent in former smokers. Also the meta-analysis, which included both lung and bladder cancers, showed a statistically significant association in current smokers, whereas the results in never smokers were equivocal; in former smokers, no association......Bulky DNA adducts are biomarkers of exposure to aromatic compounds and of the ability of the individual to metabolically activate carcinogens and to repair DNA damage. Their ability to predict cancer onset is uncertain. We have performed a pooled analysis of three prospective studies on cancer risk...

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.

Data analysis with the DIANA meta-scheduling approach

International Nuclear Information System (INIS)

Anjum, A; McClatchey, R; Willers, I

2008-01-01

The concepts, design and evaluation of the Data Intensive and Network Aware (DIANA) meta-scheduling approach for solving the challenges of data analysis being faced by CERN experiments are discussed in this paper. Our results suggest that data analysis can be made robust by employing fault tolerant and decentralized meta-scheduling algorithms supported in our DIANA meta-scheduler. The DIANA meta-scheduler supports data intensive bulk scheduling, is network aware and follows a policy centric meta-scheduling. In this paper, we demonstrate that a decentralized and dynamic meta-scheduling approach is an effective strategy to cope with increasing numbers of users, jobs and datasets. We present 'quality of service' related statistics for physics analysis through the application of a policy centric fair-share scheduling model. The DIANA meta-schedulers create a peer-to-peer hierarchy of schedulers to accomplish resource management that changes with evolving loads and is dynamic and adapts to the volatile nature of the resources

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....

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

Advances in meta-analysis: examples from internal medicine to neurology.

Science.gov (United States)

Copetti, Massimiliano; Fontana, Andrea; Graziano, Giusi; Veneziani, Federica; Siena, Federica; Scardapane, Marco; Lucisano, Giuseppe; Pellegrini, Fabio

2014-01-01

We review the state of the art in meta-analysis and data pooling following the evolution of the statistical models employed. Starting from a classic definition of meta-analysis of published data, a set of apparent antinomies which characterized the development of the meta-analytic tools are reconciled in dichotomies where the second term represents a possible generalization of the first one. Particular attention is given to the generalized linear mixed models as an overall framework for meta-analysis. Bayesian meta-analysis is discussed as a further possibility of generalization for sensitivity analysis and the use of priors as a data augmentation approach. We provide relevant examples to underline how the need for adequate methods to solve practical issues in specific areas of research have guided the development of advanced methods in meta-analysis. We show how all the advances in meta-analysis naturally merge into the unified framework of generalized linear mixed models and reconcile apparently conflicting approaches. All these complex models can be easily implemented with the standard commercial software available. © 2013 S. Karger AG, Basel.

Natural funnel asymmetries. A simulation analysis of the three basic tools of meta analysis

DEFF Research Database (Denmark)

Callot, Laurent Abdelkader Francois; Paldam, Martin

Meta-analysis studies a set of estimates of one parameter with three basic tools: The funnel diagram is the distribution of the estimates as a function of their precision; the funnel asymmetry test, FAT; and the meta average, where PET is an estimate. The FAT-PET MRA is a meta regression analysis...

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

Improved score statistics for meta-analysis in single-variant and gene-level association studies.

Science.gov (United States)

Yang, Jingjing; Chen, Sai; Abecasis, Gonçalo

2018-06-01

Meta-analysis is now an essential tool for genetic association studies, allowing them to combine large studies and greatly accelerating the pace of genetic discovery. Although the standard meta-analysis methods perform equivalently as the more cumbersome joint analysis under ideal settings, they result in substantial power loss under unbalanced settings with various case-control ratios. Here, we investigate the power loss problem by the standard meta-analysis methods for unbalanced studies, and further propose novel meta-analysis methods performing equivalently to the joint analysis under both balanced and unbalanced settings. We derive improved meta-score-statistics that can accurately approximate the joint-score-statistics with combined individual-level data, for both linear and logistic regression models, with and without covariates. In addition, we propose a novel approach to adjust for population stratification by correcting for known population structures through minor allele frequencies. In the simulated gene-level association studies under unbalanced settings, our method recovered up to 85% power loss caused by the standard methods. We further showed the power gain of our methods in gene-level tests with 26 unbalanced studies of age-related macular degeneration . In addition, we took the meta-analysis of three unbalanced studies of type 2 diabetes as an example to discuss the challenges of meta-analyzing multi-ethnic samples. In summary, our improved meta-score-statistics with corrections for population stratification can be used to construct both single-variant and gene-level association studies, providing a useful framework for ensuring well-powered, convenient, cross-study analyses. © 2018 WILEY PERIODICALS, INC.

Multivariate meta-analysis: Potential and promise

Science.gov (United States)

Jackson, Dan; Riley, Richard; White, Ian R

2011-01-01

The multivariate random effects model is a generalization of the standard univariate model. Multivariate meta-analysis is becoming more commonly used and the techniques and related computer software, although continually under development, are now in place. In order to raise awareness of the multivariate methods, and discuss their advantages and disadvantages, we organized a one day ‘Multivariate meta-analysis’ event at the Royal Statistical Society. In addition to disseminating the most recent developments, we also received an abundance of comments, concerns, insights, critiques and encouragement. This article provides a balanced account of the day's discourse. By giving others the opportunity to respond to our assessment, we hope to ensure that the various view points and opinions are aired before multivariate meta-analysis simply becomes another widely used de facto method without any proper consideration of it by the medical statistics community. We describe the areas of application that multivariate meta-analysis has found, the methods available, the difficulties typically encountered and the arguments for and against the multivariate methods, using four representative but contrasting examples. We conclude that the multivariate methods can be useful, and in particular can provide estimates with better statistical properties, but also that these benefits come at the price of making more assumptions which do not result in better inference in every case. Although there is evidence that multivariate meta-analysis has considerable potential, it must be even more carefully applied than its univariate counterpart in practice. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21268052

The Economic Value of Mangroves: A Meta-Analysis

Science.gov (United States)

Marwa Salem; D. Evan Mercer

2012-01-01

This paper presents a synthesis of the mangrove ecosystem valuation literature through a meta-regression analysis. The main contribution of this study is that it is the first meta-analysis focusing solely on mangrove forests, whereas previous studies have included different types of wetlands. The number of studies included in the regression analysis is 44 for a total...

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.

Meta-STEPP: subpopulation treatment effect pattern plot for individual patient data meta-analysis.

Science.gov (United States)

Wang, Xin Victoria; Cole, Bernard; Bonetti, Marco; Gelber, Richard D

2016-09-20

We have developed a method, called Meta-STEPP (subpopulation treatment effect pattern plot for meta-analysis), to explore treatment effect heterogeneity across covariate values in the meta-analysis setting for time-to-event data when the covariate of interest is continuous. Meta-STEPP forms overlapping subpopulations from individual patient data containing similar numbers of events with increasing covariate values, estimates subpopulation treatment effects using standard fixed-effects meta-analysis methodology, displays the estimated subpopulation treatment effect as a function of the covariate values, and provides a statistical test to detect possibly complex treatment-covariate interactions. Simulation studies show that this test has adequate type-I error rate recovery as well as power when reasonable window sizes are chosen. When applied to eight breast cancer trials, Meta-STEPP suggests that chemotherapy is less effective for tumors with high estrogen receptor expression compared with those with low expression. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

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

Meta-analysis of individual registry results enhances international registry collaboration.

Science.gov (United States)

Paxton, Elizabeth W; Mohaddes, Maziar; Laaksonen, Inari; Lorimer, Michelle; Graves, Stephen E; Malchau, Henrik; Namba, Robert S; Kärrholm, John; Rolfson, Ola; Cafri, Guy

2018-03-28

Background and purpose - Although common in medical research, meta-analysis has not been widely adopted in registry collaborations. A meta-analytic approach in which each registry conducts a standardized analysis on its own data followed by a meta-analysis to calculate a weighted average of the estimates allows collaboration without sharing patient-level data. The value of meta-analysis as an alternative to individual patient data analysis is illustrated in this study by comparing the risk of revision of porous tantalum cups versus other uncemented cups in primary total hip arthroplasties from Sweden, Australia, and a US registry (2003-2015). Patients and methods - For both individual patient data analysis and meta-analysis approaches a Cox proportional hazard model was fit for time to revision, comparing porous tantalum (n = 23,201) with other uncemented cups (n = 128,321). Covariates included age, sex, diagnosis, head size, and stem fixation. In the meta-analysis approach, treatment effect size (i.e., Cox model hazard ratio) was calculated within each registry and a weighted average for the individual registries' estimates was calculated. Results - Patient-level data analysis and meta-analytic approaches yielded the same results with the porous tantalum cups having a higher risk of revision than other uncemented cups (HR (95% CI) 1.6 (1.4-1.7) and HR (95% CI) 1.5 (1.4-1.7), respectively). Adding the US cohort to the meta-analysis led to greater generalizability, increased precision of the treatment effect, and similar findings (HR (95% CI) 1.6 (1.4-1.7)) with increased risk of porous tantalum cups. Interpretation - The meta-analytic technique is a viable option to address privacy, security, and data ownership concerns allowing more expansive registry collaboration, greater generalizability, and increased precision of treatment effects.

Systematic review with meta-analysis

DEFF Research Database (Denmark)

Roda, G; Narula, N; Pinotti, R

2017-01-01

and meta-analysis of epidemiological studies reporting on extension of ulcerative colitis to determine frequency of disease extension in patients with limited ulcerative colitis at diagnosis. METHODS: We performed a systematic literature search to identify studies on disease extension of ulcerative colitis...... (UC) and predictors of disease progression. RESULTS: Overall, 41 studies were eligible for systematic review but only 30 for meta-analysis. The overall pooled frequency of UC extension was 22.8% with colonic extension being 17.8% at 5 years and 31% at 10 years. Extension was 17.8% (95% CI 11...... in patients from North America (37.8%) than from Europe (19.6%) (Pmeta-analysis, approximately one quarter of patients with limited UC extend over time with most extension occurring during the first 10 years. Rate of extension depends on age at diagnosis and geographic origin...

Meta-analysis of Gaussian individual patient data: Two-stage or not two-stage?

Science.gov (United States)

Morris, Tim P; Fisher, David J; Kenward, Michael G; Carpenter, James R

2018-04-30

Quantitative evidence synthesis through meta-analysis is central to evidence-based medicine. For well-documented reasons, the meta-analysis of individual patient data is held in higher regard than aggregate data. With access to individual patient data, the analysis is not restricted to a "two-stage" approach (combining estimates and standard errors) but can estimate parameters of interest by fitting a single model to all of the data, a so-called "one-stage" analysis. There has been debate about the merits of one- and two-stage analysis. Arguments for one-stage analysis have typically noted that a wider range of models can be fitted and overall estimates may be more precise. The two-stage side has emphasised that the models that can be fitted in two stages are sufficient to answer the relevant questions, with less scope for mistakes because there are fewer modelling choices to be made in the two-stage approach. For Gaussian data, we consider the statistical arguments for flexibility and precision in small-sample settings. Regarding flexibility, several of the models that can be fitted only in one stage may not be of serious interest to most meta-analysis practitioners. Regarding precision, we consider fixed- and random-effects meta-analysis and see that, for a model making certain assumptions, the number of stages used to fit this model is irrelevant; the precision will be approximately equal. Meta-analysts should choose modelling assumptions carefully. Sometimes relevant models can only be fitted in one stage. Otherwise, meta-analysts are free to use whichever procedure is most convenient to fit the identified model. © 2018 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Genetic Polymorphism of Angiotensin-Converting Enzyme and Chronic Obstructive Pulmonary Disease Risk: An Updated Meta-Analysis

Directory of Open Access Journals (Sweden)

Sang Wook Kang

2016-01-01

Full Text Available The relationship between polymorphism of the angiotensin I converting enzyme (ACE gene and chronic obstructive pulmonary disease (COPD has been examined in many previous studies. However, their results were controversial. Therefore, we performed a meta-analysis to evaluate the relationship between the ACE gene and the risk of COPD. Fourteen case-control studies were included in this meta-analysis. The pooled p value, odds ratio (OR, and 95% confidence interval (95% CI were used to investigate the strength of the association. The meta-analysis was performed using comprehensive meta-analysis software. Our meta-analysis results revealed that ACE polymorphisms were not related to the risk of COPD (p>0.05 in each model. In further analyses based on ethnicity, we observed an association between insertion/deletion polymorphism of the ACE gene and risk of COPD in the Asian population (codominant 2, OR = 3.126, 95% CI = 1.919–5.093, p0.05 in each model. In conclusion, the present meta-analysis indicated that the insertion/deletion polymorphism of the ACE gene may be associated with susceptibility to COPD in the Asian population but not in the Caucasian population. However, the results of the present meta-analysis need to be confirmed in a larger sample.

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.

Mass meta-analysis in Talairach space

DEFF Research Database (Denmark)

Nielsen, Finn Årup

2004-01-01

We provide a method for mass meta-analysis in a neuroinformatics database containing stereotaxic Talairach coordinates from neuroimaging experiments. Database labels are used to group the individual experiments, e.g., according to cognitive function, and the consistent pattern of the experiments...... of experiments, and the distances to the null hypotheses are used to sort the voxels across groups of experiments. This allows for mass meta-analysis, with the construction of a list with the most prominent associations between brain areas and group labels. Furthermore, the method can be used for functional...

Methodology Series Module 6: Systematic Reviews and Meta-analysis.

Science.gov (United States)

Setia, Maninder Singh

2016-01-01

Systematic reviews and meta-analysis have become an important of biomedical literature, and they provide the "highest level of evidence" for various clinical questions. There are a lot of studies - sometimes with contradictory conclusions - on a particular topic in literature. Hence, as a clinician, which results will you believe? What will you tell your patient? Which drug is better? A systematic review or a meta-analysis may help us answer these questions. In addition, it may also help us understand the quality of the articles in literature or the type of studies that have been conducted and published (example, randomized trials or observational studies). The first step it to identify a research question for systematic review or meta-analysis. The next step is to identify the articles that will be included in the study. This will be done by searching various databases; it is important that the researcher should search for articles in more than one database. It will also be useful to form a group of researchers and statisticians that have expertise in conducting systematic reviews and meta-analysis before initiating them. We strongly encourage the readers to register their proposed review/meta-analysis with PROSPERO. Finally, these studies should be reported according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis checklist.

Citation analysis of meta-analysis articles on posttraumatic stress disorder.

Science.gov (United States)

Liao, Xi-Ming; Chen, Ping-Yan

2011-04-01

In the past two decades enormously scientific researches on posttraumatic stress disorder (PTSD) have been undertaken and many related meta-analyses have been published. Citation analysis was used to get comprehensive perspectives of meta-analysis articles (MA articles) on PTSD for the purpose of facilitating the researchers, physicians and policy-makers to understand the PTSD. MA articles on PTSD in any languages from January 1980 to March 2009 were included if they presented meta-analytical methods and received at least one citation recorded in the Web of Science (WoS). Whereas studies, in which any effect sizes of PTSD were not distinguished from other psychological disorders, were excluded. Citations to and by identified MA articles were documented basing on records in WoS. Citation analysis was used to examine distribution patterns of characteristics and citation impact of MA articles on PTSD. Canonical analysis was used to explore the relationship between the characteristics of MA articles and citation impact. Thirty-four MA articles published during 1998 and 2008 were identified and revealed multiple study topics on PTSD: 10 (29.4%) were about epidemiology, 13 (38.2%) about treatment or intervention, 6 (17.6%) about pathophysiology or neurophysiology or neuroendocrine, 3 (8.8%) about childhood and 2 (5.9%) about psychosocial adversity. Two articles cited most frequently with 456 and 145 counts were published in Journal of Consulting and Clinical Psychology by Brewin (2000) and Psychological Bulletin by Ozer (2003), respectively. Mean cited count was 7.48 ± 10.56 and mean age (year 2009 minus article publication year) was (4.24 ± 2.91) years. They had been cited approximately by 67 disciplines and by authors from 42 countries or territories. Characteristics of meta-analysis highly correlated with citation impact and reflected by canonical correlation of 0.899 (P < 0.000 01). The age of MA articles predicted their citation impact. Citation analysis would

Occupational and environmental scleroderma. Systematic review and meta-analysis.

Science.gov (United States)

Rubio-Rivas, Manuel; Moreno, Rafael; Corbella, Xavier

2017-03-01

The etiology of systemic sclerosis (SSc) remains unknown; however, several occupational and environmental factors have been implicated. Our objective was to perform a meta-analysis of all studies published on SSc associated with occupational and environmental exposure. The review was undertaken by means of MEDLINE and SCOPUS from 1960 to 2014 and using the terms: "systemic," "scleroderma," or "systemic sclerosis/chemically induced" [MesH]. The Newcastle-Ottawa Scale was used for the qualifying assessment. The inverse variance-weighted method was performed. The meta-analysis of silica exposure included 15 case-control studies [overall OR 2.81 (95%CI 1.86-4.23; p < 0.001)] and 4 cohort studies [overall RR 17.52 (95%CI 5.98-51.37; p < 0.001)]; the meta-analysis of solvents exposure included 13 case-control studies (overall OR 2.00 [95%CI 1.32-3.02; p = 0.001); the meta-analysis of breast implants exposure included 4 case-control studies (overall OR 1.68 (95%CI 1.65-1.71; p < 0.001)) and 6 cohort studies (overall RR 2.13 (95%CI 0.86-5.27; p = 0.10)); the meta-analysis of epoxy resins exposure included 4 case-control studies (overall OR 2.97 (95%CI 2.31-3.83; p < 0.001)), the meta-analysis of pesticides exposure included 3 case-control studies (overall OR 1.02 (95%CI 0.78-1.32; p = 0.90)) and, finally, the meta-analysis of welding fumes exposure included 4 studies (overall OR 1.29 (95%CI 0.44-3.74; p = 0.64)). Not enough studies citing risks related to hair dyes have been published to perform an accurate meta-analysis. Silica and solvents were the two most likely substances related to the pathogenesis of SSc. While silica is involved in particular jobs, solvents are widespread and more people are at risk of having incidental contact with them.

Hostile attribution of intent and aggressive behavior: A meta-analysis

NARCIS (Netherlands)

Orobio de Castro, B.; Veerman, J.W.; Koops, W.; Bosch, J.D.; Monshouwer, H.J.

2002-01-01

A meta-analytic review was conducted to explain divergent findings on the relation between children's aggressive behavior and hostile attribution of intent to peers. Forty-one studies with 6,017 participants were included in the analysis. Ten studies concerned representative samples from the general

Graphical augmentations to the funnel plot assess the impact of additional evidence on a meta-analysis.

Science.gov (United States)

Langan, Dean; Higgins, Julian P T; Gregory, Walter; Sutton, Alexander J

2012-05-01

We aim to illustrate the potential impact of a new study on a meta-analysis, which gives an indication of the robustness of the meta-analysis. A number of augmentations are proposed to one of the most widely used of graphical displays, the funnel plot. Namely, 1) statistical significance contours, which define regions of the funnel plot in which a new study would have to be located to change the statistical significance of the meta-analysis; and 2) heterogeneity contours, which show how a new study would affect the extent of heterogeneity in a given meta-analysis. Several other features are also described, and the use of multiple features simultaneously is considered. The statistical significance contours suggest that one additional study, no matter how large, may have a very limited impact on the statistical significance of a meta-analysis. The heterogeneity contours illustrate that one outlying study can increase the level of heterogeneity dramatically. The additional features of the funnel plot have applications including 1) informing sample size calculations for the design of future studies eligible for inclusion in the meta-analysis; and 2) informing the updating prioritization of a portfolio of meta-analyses such as those prepared by the Cochrane Collaboration. Copyright © 2012 Elsevier Inc. All rights reserved.

Curcuminoids Lower Plasma Leptin Concentrations: A Meta-analysis.

Science.gov (United States)

Atkin, Stephen L; Katsiki, Niki; Derosa, Giuseppe; Maffioli, Pamela; Sahebkar, Amirhossein

2017-12-01

Curcumin is a naturally occurring polyphenol that has been suggested to improve several metabolic diseases. Leptin is an adipokine involved in metabolic status and appetite, with marked crosstalk with other systems. Available data suggest that curcumin may affect leptin levels; therefore, this meta-analysis was performed to evaluate this. A systematic review and meta-analysis were undertaken on all randomized controlled trials of curcumin studies that included the measurement of leptin. The search included PubMed-Medline, Scopus, ISI Web of Knowledge, and Google Scholar databases. Quantitative data synthesis was performed by using a random-effects model, with standardized mean difference and 95% confidence interval as summary statistics. A funnel plot, Begg's rank correlation, and Egger's weighted regression tests assessed the presence of publication bias. Four eligible articles comprising five treatment arms were selected for the meta-analysis. Meta-analysis showed a significant decrease in plasma leptin concentrations following curcumin treatment (standardized mean difference: -0.69, 95% confidence interval: -1.16, -0.23, p = 0.003; I 2  = 76.53%). There was no evidence of publication bias. This meta-analysis showed that curcumin supplementation is associated with a decrease in leptin levels that may be regarded as a potential mechanism for the metabolic effects of curcumin. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

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

Comparing Active Pediatric Obesity Treatments Using Meta-Analysis

Science.gov (United States)

Gilles, Allyson; Cassano, Michael; Shepherd, Elizabeth J.; Higgins, Diana; Hecker, Jeffrey E.; Nangle, Douglas W.

2008-01-01

The current meta-analysis reviews research on the treatment of pediatric obesity focusing on studies that have been published since 1994. Eleven studies (22 comparisons, 115 effect sizes, N = 447) were included in the present meta-analysis. Results indicated that comprehensive behavioral interventions may be improved in at least two ways:…

Sensitivity analysis for publication bias in meta-analysis of diagnostic studies for a continuous biomarker.

Science.gov (United States)

Hattori, Satoshi; Zhou, Xiao-Hua

2018-02-10

Publication bias is one of the most important issues in meta-analysis. For standard meta-analyses to examine intervention effects, the funnel plot and the trim-and-fill method are simple and widely used techniques for assessing and adjusting for the influence of publication bias, respectively. However, their use may be subjective and can then produce misleading insights. To make a more objective inference for publication bias, various sensitivity analysis methods have been proposed, including the Copas selection model. For meta-analysis of diagnostic studies evaluating a continuous biomarker, the summary receiver operating characteristic (sROC) curve is a very useful method in the presence of heterogeneous cutoff values. To our best knowledge, no methods are available for evaluation of influence of publication bias on estimation of the sROC curve. In this paper, we introduce a Copas-type selection model for meta-analysis of diagnostic studies and propose a sensitivity analysis method for publication bias. Our method enables us to assess the influence of publication bias on the estimation of the sROC curve and then judge whether the result of the meta-analysis is sufficiently confident or should be interpreted with much caution. We illustrate our proposed method with real data. Copyright © 2017 John Wiley & Sons, Ltd.

Statistical methodology for estimating the mean difference in a meta-analysis without study-specific variance information.

Science.gov (United States)

Sangnawakij, Patarawan; Böhning, Dankmar; Adams, Stephen; Stanton, Michael; Holling, Heinz

2017-04-30

Statistical inference for analyzing the results from several independent studies on the same quantity of interest has been investigated frequently in recent decades. Typically, any meta-analytic inference requires that the quantity of interest is available from each study together with an estimate of its variability. The current work is motivated by a meta-analysis on comparing two treatments (thoracoscopic and open) of congenital lung malformations in young children. Quantities of interest include continuous end-points such as length of operation or number of chest tube days. As studies only report mean values (and no standard errors or confidence intervals), the question arises how meta-analytic inference can be developed. We suggest two methods to estimate study-specific variances in such a meta-analysis, where only sample means and sample sizes are available in the treatment arms. A general likelihood ratio test is derived for testing equality of variances in two groups. By means of simulation studies, the bias and estimated standard error of the overall mean difference from both methodologies are evaluated and compared with two existing approaches: complete study analysis only and partial variance information. The performance of the test is evaluated in terms of type I error. Additionally, we illustrate these methods in the meta-analysis on comparing thoracoscopic and open surgery for congenital lung malformations and in a meta-analysis on the change in renal function after kidney donation. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

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.

International Entrepreneurship: A Meta-Analysis on the Internationalization and Performance Relationship

NARCIS (Netherlands)

Schwens, Christian; Zapkau, F.B.; Bierwerth, Michael; Isidor, Rodrigo; Knight, Gary; Kabst, Rüdiger

2018-01-01

The article conducts a meta-analysis on the relationship between internationalization and firm performance in international entrepreneurship. Empirical evidence from 15,648 internationalizing entrepreneurial firms nested in 43 independent samples reveals a positive relationship between degree and

Road safety effects of roundabouts: A meta-analysis.

Science.gov (United States)

Elvik, Rune

2017-02-01

This paper presents a meta-analysis of the road safety effects of converting junctions to roundabouts. 44 studies containing a total of 154 estimates of effect were included. Based on a meta-regression analysis, converting junctions to roundabouts is associated with a reduction of fatal accidents of about 65% and a reduction of injury accidents of about 40%. The mean effect on property-damage-only accidents is ambiguous. Summary estimates of effect are robust for fatal and injury accidents, but vary depending on the model of meta-analysis and the treatment of outlying data points for property-damage-only accidents. A trim-and-fill analysis suggests a weak tendency for publication bias, with modest influence on summary estimates of effect. It is concluded that roundabouts are very effective in reducing traffic fatalities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Beta-binomial model for meta-analysis of odds ratios.

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Bakbergenuly, Ilyas; Kulinskaya, Elena

2017-05-20

In meta-analysis of odds ratios (ORs), heterogeneity between the studies is usually modelled via the additive random effects model (REM). An alternative, multiplicative REM for ORs uses overdispersion. The multiplicative factor in this overdispersion model (ODM) can be interpreted as an intra-class correlation (ICC) parameter. This model naturally arises when the probabilities of an event in one or both arms of a comparative study are themselves beta-distributed, resulting in beta-binomial distributions. We propose two new estimators of the ICC for meta-analysis in this setting. One is based on the inverted Breslow-Day test, and the other on the improved gamma approximation by Kulinskaya and Dollinger (2015, p. 26) to the distribution of Cochran's Q. The performance of these and several other estimators of ICC on bias and coverage is studied by simulation. Additionally, the Mantel-Haenszel approach to estimation of ORs is extended to the beta-binomial model, and we study performance of various ICC estimators when used in the Mantel-Haenszel or the inverse-variance method to combine ORs in meta-analysis. The results of the simulations show that the improved gamma-based estimator of ICC is superior for small sample sizes, and the Breslow-Day-based estimator is the best for n⩾100. The Mantel-Haenszel-based estimator of OR is very biased and is not recommended. The inverse-variance approach is also somewhat biased for ORs≠1, but this bias is not very large in practical settings. Developed methods and R programs, provided in the Web Appendix, make the beta-binomial model a feasible alternative to the standard REM for meta-analysis of ORs. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd. © 2017 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

Steep discounting of delayed monetary and food rewards in obesity: a meta-analysis.

Science.gov (United States)

Amlung, M; Petker, T; Jackson, J; Balodis, I; MacKillop, J

2016-08-01

An increasing number of studies have investigated delay discounting (DD) in relation to obesity, but with mixed findings. This meta-analysis synthesized the literature on the relationship between monetary and food DD and obesity, with three objectives: (1) to characterize the relationship between DD and obesity in both case-control comparisons and continuous designs; (2) to examine potential moderators, including case-control v. continuous design, money v. food rewards, sample sex distribution, and sample age (18 years); and (3) to evaluate publication bias. From 134 candidate articles, 39 independent investigations yielded 29 case-control and 30 continuous comparisons (total n = 10 278). Random-effects meta-analysis was conducted using Cohen's d as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger tests, meta-regression of publication year and effect size, and imputation of missing studies. The primary analysis revealed a medium effect size across studies that was highly statistically significant (d = 0.43, p food rewards and child/adolescent samples. Limited evidence of publication bias was present, although the Begg-Mazumdar test and meta-regression suggested a slightly diminishing effect size over time. Steep DD of food and money appears to be a robust feature of obesity that is relatively consistent across the DD assessment methodologies and study designs examined. These findings are discussed in the context of research on DD in drug addiction, the neural bases of DD in obesity, and potential clinical applications.

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

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

Scientists Admitting to Plagiarism: A Meta-analysis of Surveys.

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Pupovac, Vanja; Fanelli, Daniele

2015-10-01

We conducted a systematic review and meta-analysis of anonymous surveys asking scientists whether they ever committed various forms of plagiarism. From May to December 2011 we searched 35 bibliographic databases, five grey literature databases and hand searched nine journals for potentially relevant studies. We included surveys that asked scientists if, in a given recall period, they had committed or knew of a colleague who committed plagiarism, and from each survey extracted the proportion of those who reported at least one case. Studies that focused on academic (i.e. student) plagiarism were excluded. Literature searches returned 12,460 titles from which 17 relevant survey studies were identified. Meta-analysis of studies reporting committed (N = 7) and witnessed (N = 11) plagiarism yielded a pooled estimate of, respectively, 1.7% (95% CI 1.2-2.4) and 30% (95% CI 17-46). Basic methodological factors, including sample size, year of survey, delivery method and whether survey questions were explicit rather than indirect made a significant difference on survey results. Even after controlling for these methodological factors, between-study differences in admission rates were significantly above those expected by sampling error alone and remained largely unexplained. Despite several limitations of the data and of this meta-analysis, we draw three robust conclusions: (1) The rate at which scientists report knowing a colleague who committed plagiarism is higher than for data fabrication and falsification; (2) The rate at which scientists report knowing a colleague who committed plagiarism is correlated to that of fabrication and falsification; (3) The rate at which scientists admit having committed either form of misconduct (i.e. fabrication, falsification and plagiarism) in surveys has declined over time.

Energy efficiency in Germany - a meta-analysis. Analysis and recommendations

International Nuclear Information System (INIS)

Bauernhansl, Thomas

2014-01-01

The Stuttgart Institute of energy efficiency in production compiled the first meta-analysis ''Energy Efficiency in Germany''.It provides facts and figures on the development atatus and knowledge level of energy efficiency in Germany. The study shows the contribution have been made by individual measures and the potentials which are known, but have not yet been lifted. For this meta-analysis more than 250 items available from research institutions, government departments, professional and industry associations have been identified with the main topic of energy efficiency and evaluated. It provides an overview of the status of development and is an important reference work for industry, associations and politics. [de

Meta-analysis of workplace physical activity interventions.

Science.gov (United States)

Conn, Vicki S; Hafdahl, Adam R; Cooper, Pamela S; Brown, Lori M; Lusk, Sally L

2009-10-01

Most adults do not achieve adequate physical activity levels. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from such programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21); fitness (0.57); lipids (0.13); anthropometric measures (0.08); work attendance (0.19); and job stress (0.33). The significant effect size for diabetes risk (0.98) is less robust given small sample sizes. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on VO2max of 3.5 mL/kg/min; for lipids, -0.2 on the ratio of total cholesterol to high-density lipoprotein; and for diabetes risk, -12.6 mg/dL on fasting glucose. These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity.

Hypothyroidism and carpal tunnel syndrome: a meta-analysis.

Science.gov (United States)

Shiri, Rahman

2014-12-01

This study aimed to assess the magnitude of the association between hypothyroidism and carpal tunnel syndrome (CTS). Eighteen studies were included in a random-effects meta-analysis. A meta-analysis of the studies that did not control their estimates for any confounder showed an association between a thyroid disease (hypo- or hyperthyroidism) and CTS (N = 9,573, effect size [ES] = 1.32 (95% confidence interval [CI], 1.04-1.68) and between hypothyroidism and CTS (N = 64,531, ES = 2.15 [95% CI, 1.64-2.83]). When a meta-analysis limited to the studies that controlled their estimates for some potential confounders, the association between a thyroid disease and CTS disappeared (N = 4,799, ES = 1.17 [95% CI, 0.71-1.92], I(2) = 0%), and the effect size for hypothyroidism largely attenuated (N = 71,133, ES = 1.44 [95% CI, 1.27-1.63], I(2) = 0%). Moreover, there was evidence of publication bias. This meta-analysis found only a modest association between hypothyroidism and CTS. Confounding and publication bias may still account for part of the remaining excess risk. © 2014 Wiley Periodicals, Inc.

Systematic reviews with meta-analysis: Why, when, and how?

NARCIS (Netherlands)

Crocetti, E.

2016-01-01

Systematic reviews with meta-analysis represent the gold standard for conducting reliable and transparent reviews of the literature. The purpose of this article is threefold: (a) to address why and when it is worthwhile to conduct a systematic review with meta-analysis, covering advantages of this

CrossFit Overview: Systematic Review and Meta-analysis.

Science.gov (United States)

Claudino, João Gustavo; Gabbett, Tim J; Bourgeois, Frank; Souza, Helton de Sá; Miranda, Rafael Chagas; Mezêncio, Bruno; Soncin, Rafael; Cardoso Filho, Carlos Alberto; Bottaro, Martim; Hernandez, Arnaldo Jose; Amadio, Alberto Carlos; Serrão, Julio Cerca

2018-02-26

CrossFit is recognized as one of the fastest growing high-intensity functional training modes in the world. However, scientific data regarding the practice of CrossFit is sparse. Therefore, the objective of this study is to analyze the findings of scientific literature related to CrossFit via systematic review and meta-analysis. Systematic searches of the PubMed, Web of Science, Scopus, Bireme/MedLine, and SciELO online databases were conducted for articles reporting the effects of CrossFit training. The systematic review followed the PRISMA guidelines. The Oxford Levels of Evidence was used for all included articles, and only studies that investigated the effects of CrossFit as a training program were included in the meta-analysis. For the meta-analysis, effect sizes (ESs) with 95% confidence interval (CI) were calculated and heterogeneity was assessed using a random-effects model. Thirty-one articles were included in the systematic review and four were included in the meta-analysis. However, only two studies had a high level of evidence at low risk of bias. Scientific literature related to CrossFit has reported on body composition, psycho-physiological parameters, musculoskeletal injury risk, life and health aspects, and psycho-social behavior. In the meta-analysis, significant results were not found for any variables. The current scientific literature related to CrossFit has few studies with high level of evidence at low risk of bias. However, preliminary data has suggested that CrossFit practice is associated with higher levels of sense of community, satisfaction, and motivation.

Self-Informant Agreement in Well-Being Ratings: A Meta-Analysis

Science.gov (United States)

Schneider, Leann; Schimmack, Ulrich

2009-01-01

A meta-analysis of published studies that reported correlations between self-ratings and informant ratings of well-being (life-satisfaction, happiness, positive affect, negative affect) was performed. The average self-informant correlation based on 44 independent samples and 81 correlations for a total of 8,897 participants was r = 0.42 [99%…

L2 Reading Comprehension and Its Correlates: A Meta-Analysis

Science.gov (United States)

Jeon, Eun Hee; Yamashita, Junko

2014-01-01

The present meta-analysis examined the overall average correlation (weighted for sample size and corrected for measurement error) between passage-level second language (L2) reading comprehension and 10 key reading component variables investigated in the research domain. Four high-evidence correlates (with 18 or more accumulated effect sizes: L2…

Efficiency enhancement of optimized Latin hypercube sampling strategies: Application to Monte Carlo uncertainty analysis and meta-modeling

Science.gov (United States)

Rajabi, Mohammad Mahdi; Ataie-Ashtiani, Behzad; Janssen, Hans

2015-02-01

The majority of literature regarding optimized Latin hypercube sampling (OLHS) is devoted to increasing the efficiency of these sampling strategies through the development of new algorithms based on the combination of innovative space-filling criteria and specialized optimization schemes. However, little attention has been given to the impact of the initial design that is fed into the optimization algorithm, on the efficiency of OLHS strategies. Previous studies, as well as codes developed for OLHS, have relied on one of the following two approaches for the selection of the initial design in OLHS: (1) the use of random points in the hypercube intervals (random LHS), and (2) the use of midpoints in the hypercube intervals (midpoint LHS). Both approaches have been extensively used, but no attempt has been previously made to compare the efficiency and robustness of their resulting sample designs. In this study we compare the two approaches and show that the space-filling characteristics of OLHS designs are sensitive to the initial design that is fed into the optimization algorithm. It is also illustrated that the space-filling characteristics of OLHS designs based on midpoint LHS are significantly better those based on random LHS. The two approaches are compared by incorporating their resulting sample designs in Monte Carlo simulation (MCS) for uncertainty propagation analysis, and then, by employing the sample designs in the selection of the training set for constructing non-intrusive polynomial chaos expansion (NIPCE) meta-models which subsequently replace the original full model in MCSs. The analysis is based on two case studies involving numerical simulation of density dependent flow and solute transport in porous media within the context of seawater intrusion in coastal aquifers. We show that the use of midpoint LHS as the initial design increases the efficiency and robustness of the resulting MCSs and NIPCE meta-models. The study also illustrates that this

MicroRNA meta-signature of oral cancer: evidence from a meta-analysis.

Science.gov (United States)

Zeljic, Katarina; Jovanovic, Ivan; Jovanovic, Jasmina; Magic, Zvonko; Stankovic, Aleksandra; Supic, Gordana

2018-03-01

It was the aim of the study to identify commonly deregulated miRNAs in oral cancer patients by performing a meta-analysis of previously published miRNA expression profiles in cancer and matched normal non-cancerous tissue in such patients. Meta-analysis included seven independent studies analyzed by a vote-counting method followed by bioinformatic enrichment analysis. Amongst seven independent studies included in the meta-analysis, 20 miRNAs were found to be deregulated in oral cancer when compared with non-cancerous tissue. Eleven miRNAs were consistently up-regulated in three or more studies (miR-21-5p, miR-31-5p, miR-135b-5p, miR-31-3p, miR-93-5p, miR-34b-5p, miR-424-5p, miR-18a-5p, miR-455-3p, miR-450a-5p, miR-21-3p), and nine were down-regulated (miR-139-5p, miR-30a-3p, miR-376c-3p, miR-885-5p, miR-375, miR-486-5p, miR-411-5p, miR-133a-3p, miR-30a-5p). The meta-signature of identified miRNAs was functionally characterized by KEGG enrichment analysis. Twenty-four KEGG pathways were significantly enriched, and TGF-beta signaling was the most enriched signaling pathway. The highest number of meta-signature miRNAs was involved in the sphingolipid signaling pathway. Natural killer cell-mediated cytotoxicity was the pathway with most genes regulated by identified miRNAs. The rest of the enriched pathways in our miRNA list describe different malignancies and signaling. The identified miRNA meta-signature might be considered as a potential battery of biomarkers when distinguishing oral cancer tissue from normal, non-cancerous tissue. Further mechanistic studies are warranted in order to confirm and fully elucidate the role of deregulated miRNAs in oral cancer.

Meta-analysis in a nutshell: Techniques and general findings

DEFF Research Database (Denmark)

Paldam, Martin

2015-01-01

The purpose of this article is to introduce the technique and main findings of meta-analysis to the reader, who is unfamiliar with the field and has the usual objections. A meta-analysis is a quantitative survey of a literature reporting estimates of the same parameter. The funnel showing...

Does chocolate reduce blood pressure? A meta-analysis

Directory of Open Access Journals (Sweden)

Ried Karin

2010-06-01

Full Text Available Abstract Background Dark chocolate and flavanol-rich cocoa products have attracted interest as an alternative treatment option for hypertension, a known risk factor for cardiovascular disease. Previous meta-analyses concluded that cocoa-rich foods may reduce blood pressure. Recently, several additional trials have been conducted with conflicting results. Our study summarises current evidence on the effect of flavanol-rich cocoa products on blood pressure in hypertensive and normotensive individuals. Methods We searched Medline, Cochrane and international trial registries between 1955 and 2009 for randomised controlled trials investigating the effect of cocoa as food or drink compared with placebo on systolic and diastolic blood pressure (SBP/DBP for a minimum duration of 2 weeks. We conducted random effects meta-analysis of all studies fitting the inclusion criteria, as well as subgroup analysis by baseline blood pressure (hypertensive/normotensive. Meta-regression analysis explored the association between type of treatment, dosage, duration or baseline blood pressure and blood pressure outcome. Statistical significance was set at P Results Fifteen trial arms of 13 assessed studies met the inclusion criteria. Pooled meta-analysis of all trials revealed a significant blood pressure-reducing effect of cocoa-chocolate compared with control (mean BP change ± SE: SBP: -3.2 ± 1.9 mmHg, P = 0.001; DBP: -2.0 ± 1.3 mmHg, P = 0.003. However, subgroup meta-analysis was significant only for the hypertensive or prehypertensive subgroups (SBP: -5.0 ± 3.0 mmHg; P = 0.0009; DBP: -2.7 ± 2.2 mm Hg, P = 0.01, while BP was not significantly reduced in the normotensive subgroups (SBP: -1.6 ± 2.3 mmHg, P = 0.17; DBP: -1.3 ± 1.6 mmHg, P = 0.12. Nine trials used chocolate containing 50% to 70% cocoa compared with white chocolate or other cocoa-free controls, while six trials compared high- with low-flavanol cocoa products. Daily flavanol dosages ranged from 30

The relationship between nature connectedness and happiness: a meta-analysis

Directory of Open Access Journals (Sweden)

Colin A. Capaldi

2014-09-01

Full Text Available Research suggests that contact with nature can be beneficial, for example leading to improvements in mood, cognition, and health. A distinct but related idea is the personality construct of subjective nature connectedness, a stable individual difference in cognitive, affective, and experiential connection with the natural environment. Subjective nature connectedness is a strong predictor of pro-environmental attitudes and behaviours that may also be positively associated with subjective well-being. This meta-analysis was conducted to examine the relationship between nature connectedness and happiness. Based on 30 samples (n = 8,523, a fixed-effect meta-analysis found a small but significant effect size (r = .19. Those who are more connected to nature tended to experience more positive affect, vitality, and life satisfaction compared to those less connected to nature. Publication status, year, average age, and percentage of females in the sample were not significant moderators. Vitality had the strongest relationship with nature connectedness (r = .24, followed by positive affect (r = .22 and life satisfaction (r = .17. In terms of specific nature connectedness measures, associations were the strongest between happiness and inclusion of nature in self (r = .27, compared to nature relatedness (r = .18 and connectedness to nature (r = .18. This research highlights the importance of considering personality when examining the psychological benefits of nature. The results suggest that closer human-nature relationships do not have to come at the expense of happiness. Rather, this meta-analysis shows that being connected to nature and feeling happy are, in fact, connected.

Forecasting urban water demand: A meta-regression analysis.

Science.gov (United States)

Sebri, Maamar

2016-12-01

Water managers and planners require accurate water demand forecasts over the short-, medium- and long-term for many purposes. These range from assessing water supply needs over spatial and temporal patterns to optimizing future investments and planning future allocations across competing sectors. This study surveys the empirical literature on the urban water demand forecasting using the meta-analytical approach. Specifically, using more than 600 estimates, a meta-regression analysis is conducted to identify explanations of cross-studies variation in accuracy of urban water demand forecasting. Our study finds that accuracy depends significantly on study characteristics, including demand periodicity, modeling method, forecasting horizon, model specification and sample size. The meta-regression results remain robust to different estimators employed as well as to a series of sensitivity checks performed. The importance of these findings lies in the conclusions and implications drawn out for regulators and policymakers and for academics alike. Copyright © 2016. Published by Elsevier Ltd.

Graphics and Statistics for Cardiology: Data visualisation for meta-analysis.

Science.gov (United States)

Kiran, Amit; Crespillo, Abel Pérez; Rahimi, Kazem

2017-01-01

Graphical displays play a pivotal role in understanding data sets and disseminating results. For meta-analysis, they are instrumental in presenting findings from multiple studies. This report presents guidance to authors wishing to submit graphical displays as part of their meta-analysis to a clinical cardiology journal, such as HeartWhen using graphical displays for meta-analysis, we recommend the following: Use a flow diagram to describe the number of studies returned from the initial search, the inclusion/exclusion criteria applied and the final number of studies used in the meta-analysis.Present results from the meta-analysis using a figure that incorporates a forest plot and underlying (tabulated) statistics, including test for heterogeneity.Use displays such as funnel plot (minimum 10 studies) and Galbraith plot to visually present distribution of effect sizes or associations in order to evaluate small-study effects and publication bias).For meta-regression, the bubble plot is a useful display for assessing associations by study-level factors.Final checks on graphs, such as appropriate use of axis scale, line pattern, text size and graph resolution, should always be performed. 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/.

Meta-analysis of expression and function of neprilysin in Alzheimer's disease.

Science.gov (United States)

Zhang, Huifeng; Liu, Dan; Wang, Yixing; Huang, Huanhuan; Zhao, Yujia; Zhou, Hui

2017-09-14

Neprilysin (NEP) is one of the most important Aβ-degrading enzymes, and its expression and activity in Alzheimer's brain have been widely reported, but the results remain debatable. Thus, the meta-analysis was performed to elucidate the role of NEP in Alzheimer's disease (AD). The relevant case-control or cohort studies were retrieved according to our inclusion/exclusion criteria. Six studies with 123 controls and 141 AD cases, seven studies with 102 controls and 90 AD cases, and four studies with 93 controls and 132 AD cases were included in meta-analysis of NEP's protein, mRNA, and enzyme activity respectively. We conducted Meta regression to detect the sources of heterogeneity and further performed cumulative meta-analysis or subgroup analysis. Our meta-analysis revealed a significantly lower level of NEP mRNA (SMD=-0.44, 95%CI: -0.87, -0.00, p=0.049) in AD cases than in non-AD cases, and such pattern was not altered over time in the cumulative meta-analysis. However, the decrease of NEP protein (SMD=-0.18, 95%CI: -0.62, 0.25) and enzyme activity (SMD=-0.35, 95%CI: -1.03, 0.32) in AD cases did not pass the significance check, while the cumulative meta-analysis by average age showed the pooled effect became insignificant as adding the studies with younger subjects, which indicates that the protein expression and enzyme activity of NEP in the cortex are affected by age. Therefore, the present meta-analysis suggests the need of further investigation of roles of NEP in AD pathogenesis and treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

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...

Meta-analysis in epidemiology | Yach | South African Medical Journal

African Journals Online (AJOL)

Meta-analysis is the structured and systematic qualitative and quantitative integration of the results of several independent studies (Le. the epidemiology of results). As in any epidemiological study, a meta-analysis needs to start with clearly stated aims and objectives. Attention needs to be paid to selection bias in selecting ...

Visuo-Spatial Performance in Autism: A Meta-analysis

OpenAIRE

Muth, Anne; Honekopp, Johannes; Falter, Christine

2014-01-01

Visuo-spatial skills are believed to be enhanced in autism spectrum disorders (ASDs). This meta-analysis tests the current state of evidence for Figure Disembedding, Block Design, Mental Rotation and Navon tasks in ASD and neurotypicals. Block Design (d = 0.32) and Figure Disembedding (d = 0.26) showed superior performance for ASD with large heterogeneity that is unaccounted for. No clear differences were found for Mental Rotation. ASD samples showed a stronger local processing preference for...

Meta-analysis of Genome-Wide Association Studies for Extraversion

DEFF Research Database (Denmark)

van den Berg, Stéphanie M; de Moor, Marleen H M; Verweij, K. J. H.

2016-01-01

small sample sizes of those studies. Here, we report on a large meta-analysis of GWA studies for extraversion in 63,030 subjects in 29 cohorts. Extraversion item data from multiple personality inventories were harmonized across inventories and cohorts. No genome-wide significant associations were found...... at the single nucleotide polymorphism (SNP) level but there was one significant hit at the gene level for a long non-coding RNA site (LOC101928162). Genome-wide complex trait analysis in two large cohorts showed that the additive variance explained by common SNPs was not significantly different from zero...

When Is Hub Gene Selection Better than Standard Meta-Analysis?

Science.gov (United States)

Langfelder, Peter; Mischel, Paul S.; Horvath, Steve

2013-01-01

Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when) hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data). Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis) and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility) in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA) in three comprehensive and unbiased empirical studies: (1) Finding genes predictive of lung cancer survival, (2) finding methylation markers related to age, and (3) finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1). However, standard meta-analysis methods perform as good as (if not better than) a consensus network approach in terms of validation success (criterion 2). The article also reports a comparison of meta-analysis techniques applied to

When is hub gene selection better than standard meta-analysis?

Directory of Open Access Journals (Sweden)

Peter Langfelder

Full Text Available Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data. Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA in three comprehensive and unbiased empirical studies: (1 Finding genes predictive of lung cancer survival, (2 finding methylation markers related to age, and (3 finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1. However, standard meta-analysis methods perform as good as (if not better than a consensus network approach in terms of validation success (criterion 2. The article also reports a comparison of meta-analysis techniques

When is hub gene selection better than standard meta-analysis?

Science.gov (United States)

Langfelder, Peter; Mischel, Paul S; Horvath, Steve

2013-01-01

Since hub nodes have been found to play important roles in many networks, highly connected hub genes are expected to play an important role in biology as well. However, the empirical evidence remains ambiguous. An open question is whether (or when) hub gene selection leads to more meaningful gene lists than a standard statistical analysis based on significance testing when analyzing genomic data sets (e.g., gene expression or DNA methylation data). Here we address this question for the special case when multiple genomic data sets are available. This is of great practical importance since for many research questions multiple data sets are publicly available. In this case, the data analyst can decide between a standard statistical approach (e.g., based on meta-analysis) and a co-expression network analysis approach that selects intramodular hubs in consensus modules. We assess the performance of these two types of approaches according to two criteria. The first criterion evaluates the biological insights gained and is relevant in basic research. The second criterion evaluates the validation success (reproducibility) in independent data sets and often applies in clinical diagnostic or prognostic applications. We compare meta-analysis with consensus network analysis based on weighted correlation network analysis (WGCNA) in three comprehensive and unbiased empirical studies: (1) Finding genes predictive of lung cancer survival, (2) finding methylation markers related to age, and (3) finding mouse genes related to total cholesterol. The results demonstrate that intramodular hub gene status with respect to consensus modules is more useful than a meta-analysis p-value when identifying biologically meaningful gene lists (reflecting criterion 1). However, standard meta-analysis methods perform as good as (if not better than) a consensus network approach in terms of validation success (criterion 2). The article also reports a comparison of meta-analysis techniques applied to

Meta-Analysis of Workplace Physical Activity Interventions

Science.gov (United States)

Conn, Vicki S.; Hafdahl, Adam R.; Cooper, Pamela S.; Brown, Lori M.; Lusk, Sally L.

2009-01-01

Context Most adults do not achieve adequate physical activity. Despite the potential benefits of worksite health promotion, no previous comprehensive meta-analysis has summarized health and physical activity behavior outcomes from these programs. This comprehensive meta-analysis integrated the extant wide range of worksite physical activity intervention research. Evidence acquisition Extensive searching located published and unpublished intervention studies reported from 1969 through 2007. Results were coded from primary studies. Random-effects meta-analytic procedures, including moderator analyses, were completed in 2008. Evidence synthesis Effects on most variables were substantially heterogeneous because diverse studies were included. Standardized mean difference (d) effect sizes were synthesized across approximately 38,231 subjects. Significantly positive effects were observed for physical activity behavior (0.21), fitness (0.57), lipids (0.13), anthropometric measures (0.08), work attendance (0.19), and job stress (0.33). The significant effect size for diabetes risk (0.98) is more tentative given small sample sizes. Significant heterogeneity documents intervention effects varied across studies. The mean effect size for fitness corresponds to a difference between treatment minus control subjects' means on V02max of 3.5 mL/kg/min; for lipids, −0.2 on total cholesterol:HDL; and for diabetes risk, −12.6 mg/dL on fasting glucose. Conclusions These findings document that some workplace physical activity interventions can improve both health and important worksite outcomes. Effects were variable for most outcomes, reflecting the diversity of primary studies. Future primary research should compare interventions to confirm causal relationships and further explore heterogeneity. PMID:19765506

The Potential for Meta-Analysis to Support Decision Analysis in Ecology

Science.gov (United States)

Mengersen, Kerrie; MacNeil, M. Aaron; Caley, M. Julian

2015-01-01

Meta-analysis and decision analysis are underpinned by well-developed methods that are commonly applied to a variety of problems and disciplines. While these two fields have been closely linked in some disciplines such as medicine, comparatively little attention has been paid to the potential benefits of linking them in ecology, despite reasonable…

Macroeconomics of Natural Disasters: Strengths and Weaknesses of Meta-Analysis Versus Review of Literature.

Science.gov (United States)

A G van Bergeijk, Peter; Lazzaroni, Sara

2015-06-01

We use the case of the macroeconomic impact of natural disasters to analyze strengths and weaknesses of meta-analysis in an emerging research field. Macroeconomists have published on this issue since 2002 (we identified 60 studies to date). The results of the studies are contradictory and therefore the need to synthesize the available research is evident. Meta-analysis is a useful method in this field. An important aim of our article is to show how one can use the identified methodological characteristics to better understand the robustness and importance of new findings. To provide a comparative perspective, we contrast our meta-analysis and its findings with the major influential research synthesis in the field: the IPCC's 2012 special report Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation. We show that the IPCC could have been more confident about the negative economic impact of disasters and more transparent on inclusion and qualification of studies, if it had been complemented by a meta-analysis. Our meta-analysis shows that, controlling for modeling strategies and data set, the impact of disasters is significantly negative. The evidence is strongest for direct costs studies where we see no difference between our larger sample and the studies included in the IPCC report. Direct cost studies and indirect cost studies differ significantly, both in terms of the confidence that can be attached to a negative impact of natural disasters and in terms of the sources of heterogeneity of the findings reported in the primary studies. © 2015 Society for Risk Analysis.

Glucocorticosteroids for sepsis : systematic review with meta-analysis and trial sequential analysis

NARCIS (Netherlands)

Volbeda, M.; Wetterslev, J.; Gluud, C.; Zijlstra, J. G.; van der Horst, I. C. C.; Keus, F.

Glucocorticosteroids (steroids) are widely used for sepsis patients. However, the potential benefits and harms of both high and low dose steroids remain unclear. A systematic review of randomised clinical trials with meta-analysis and trial sequential analysis (TSA) might shed light on this

Genome-wide association study and meta-analysis find that over 40 loci affect risk of type 1 diabetes

DEFF Research Database (Denmark)

Barrett, Jeffrey C; Clayton, David G; Concannon, Patrick

2009-01-01

Type 1 diabetes (T1D) is a common autoimmune disorder that arises from the action of multiple genetic and environmental risk factors. We report the findings of a genome-wide association study of T1D, combined in a meta-analysis with two previously published studies. The total sample set included 7......,514 cases and 9,045 reference samples. Forty-one distinct genomic locations provided evidence for association with T1D in the meta-analysis (P

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....

Psychotherapy for chronic major depression and dysthymia: A meta analysis.

NARCIS (Netherlands)

Cuijpers, P.; Straten, van A.; Schuurmans, J.; Oppen, van P.C.; Hollon, S.D.; Andersson, G.

2009-01-01

Abstract Although several studies have examined the effects of psychotherapy on chronic depression and dysthymia, no meta-analysis has been conducted to integrate results of these studies. We conducted a meta-analysis of 16 randomized trials examining the effects of psychotherapy on chronic

Does chocolate reduce blood pressure? A meta-analysis.

Science.gov (United States)

Ried, Karin; Sullivan, Thomas; Fakler, Peter; Frank, Oliver R; Stocks, Nigel P

2010-06-28

Dark chocolate and flavanol-rich cocoa products have attracted interest as an alternative treatment option for hypertension, a known risk factor for cardiovascular disease. Previous meta-analyses concluded that cocoa-rich foods may reduce blood pressure. Recently, several additional trials have been conducted with conflicting results. Our study summarises current evidence on the effect of flavanol-rich cocoa products on blood pressure in hypertensive and normotensive individuals. We searched Medline, Cochrane and international trial registries between 1955 and 2009 for randomised controlled trials investigating the effect of cocoa as food or drink compared with placebo on systolic and diastolic blood pressure (SBP/DBP) for a minimum duration of 2 weeks. We conducted random effects meta-analysis of all studies fitting the inclusion criteria, as well as subgroup analysis by baseline blood pressure (hypertensive/normotensive). Meta-regression analysis explored the association between type of treatment, dosage, duration or baseline blood pressure and blood pressure outcome. Statistical significance was set at P chocolate compared with control (mean BP change +/- SE: SBP: -3.2 +/- 1.9 mmHg, P = 0.001; DBP: -2.0 +/- 1.3 mmHg, P = 0.003). However, subgroup meta-analysis was significant only for the hypertensive or prehypertensive subgroups (SBP: -5.0 +/- 3.0 mmHg; P = 0.0009; DBP: -2.7 +/- 2.2 mm Hg, P = 0.01), while BP was not significantly reduced in the normotensive subgroups (SBP: -1.6 +/- 2.3 mmHg, P = 0.17; DBP: -1.3 +/- 1.6 mmHg, P = 0.12). Nine trials used chocolate containing 50% to 70% cocoa compared with white chocolate or other cocoa-free controls, while six trials compared high- with low-flavanol cocoa products. Daily flavanol dosages ranged from 30 mg to 1000 mg in the active treatment groups, and interventions ran for 2 to 18 weeks. Meta-regression analysis found study design and type of control to be borderline significant but possibly indirect predictors

Gender role affects experimental pain responses: a systematic review with meta-analysis.

Science.gov (United States)

Alabas, O A; Tashani, O A; Tabasam, G; Johnson, M I

2012-10-01

Gender role refers to the culturally and socially constructed meanings that describe how women and men should behave in certain situations according to feminine and masculine roles learned throughout life. The aim of this meta-analysis was to evaluate the relationship between gender role and experimental pain responses in healthy human participants. We searched computerized databases for studies published between January 1950 and May 2011 that had measured gender role in healthy human adults and pain response to noxious stimuli. Studies were entered into a meta-analysis if they calculated a correlation coefficient (r) for gender role and experimental pain. Searches yielded 4465 'hits' and 13 studies were eligible for review. Sample sizes were 67-235 participants and the proportion of female participants was 45-67%. Eight types of gender role instrument were used. Meta-analysis of six studies (406 men and 539 women) found a significant positive correlation between masculine and feminine personality traits and pain threshold and tolerance, with a small effect size (r = 0.17, p = 0.01). Meta-analysis of four studies (263 men and 297 women) found a significant negative correlation between gender stereotypes specific to pain and pain threshold and tolerance, with a moderate effect size (r = -0.41, p Gender stereotypes specific to pain scales showed stronger associations with sex differences in pain sensitivity response than masculine and feminine personality trait scales. © 2012 European Federation of International Association for the Study of Pain Chapters.

A meta-analysis of the impacts of genetically modified crops.

Directory of Open Access Journals (Sweden)

Wilhelm Klümper

Full Text Available Despite the rapid adoption of genetically modified (GM crops by farmers in many countries, controversies about this technology continue. Uncertainty about GM crop impacts is one reason for widespread public suspicion.We carry out a meta-analysis of the agronomic and economic impacts of GM crops to consolidate the evidence.Original studies for inclusion were identified through keyword searches in ISI Web of Knowledge, Google Scholar, EconLit, and AgEcon Search.Studies were included when they build on primary data from farm surveys or field trials anywhere in the world, and when they report impacts of GM soybean, maize, or cotton on crop yields, pesticide use, and/or farmer profits. In total, 147 original studies were included.Analysis of mean impacts and meta-regressions to examine factors that influence outcomes.On average, GM technology adoption has reduced chemical pesticide use by 37%, increased crop yields by 22%, and increased farmer profits by 68%. Yield gains and pesticide reductions are larger for insect-resistant crops than for herbicide-tolerant crops. Yield and profit gains are higher in developing countries than in developed countries.Several of the original studies did not report sample sizes and measures of variance.The meta-analysis reveals robust evidence of GM crop benefits for farmers in developed and developing countries. Such evidence may help to gradually increase public trust in this technology.

Motor function and incident dementia: a systematic review and meta-analysis.

Science.gov (United States)

Kueper, Jacqueline Kathleen; Speechley, Mark; Lingum, Navena Rebecca; Montero-Odasso, Manuel

2017-09-01

cognitive and mobility decline are interrelated processes, whereby mobility decline coincides or precedes the onset of cognitive decline. to assess whether there is an association between performance on motor function tests and incident dementia. electronic database, grey literature and hand searching identified studies testing for associations between baseline motor function and incident dementia in older adults. of 2,540 potentially relevant documents, 37 met the final inclusion criteria and were reviewed qualitatively. Three meta-analyses were conducted using data from 10 studies. Three main motor domains-upper limb motor function, parkinsonism and lower limb motor function-emerged as associated with increased risk of incident dementia. Studies including older adults without neurological overt disease found a higher risk of incident dementia associated with poorer performance on composite motor function scores, balance and gait velocity (meta-analysis pooled HR = 1.94, 95% CI: 1.41, 2.65). Mixed results were found across different study samples for upper limb motor function, overall parkinsonism (meta-analysis pooled OR = 3.05, 95% CI: 1.31, 7.08), bradykinesia and rigidity. Studies restricted to older adults with Parkinson's Disease found weak or no association with incident dementia even for motor domains highly associated in less restrictive samples. Tremor was not associated with an increased risk of dementia in any population (meta-analysis pooled HR = 0.80, 95% CI 0.31, 2.03). lower limb motor function was associated with increased risk of developing dementia, while tremor and hand grip strength were not. Our results support future research investigating the inclusion of quantitative motor assessment, specifically gait velocity tests, for clinical dementia risk evaluation. © The Author 2017. Published by Oxford University Press on behalf of the British Geriatrics Society.All rights reserved. For permissions, please email: journals.permissions@oup.com

Mediastinal lymph node dissection versus mediastinal lymph node sampling for early stage non-small cell lung cancer: a systematic review and meta-analysis.

Science.gov (United States)

Huang, Xiongfeng; Wang, Jianmin; Chen, Qiao; Jiang, Jielin

2014-01-01

This systematic review and meta-analysis aimed to evaluate the overall survival, local recurrence, distant metastasis, and complications of mediastinal lymph node dissection (MLND) versus mediastinal lymph node sampling (MLNS) in stage I-IIIA non-small cell lung cancer (NSCLC) patients. A systematic search of published literature was conducted using the main databases (MEDLINE, PubMed, EMBASE, and Cochrane databases) to identify relevant randomized controlled trials that compared MLND vs. MLNS in NSCLC patients. Methodological quality of included randomized controlled trials was assessed according to the criteria from the Cochrane Handbook for Systematic Review of Interventions (Version 5.1.0). Meta-analysis was performed using The Cochrane Collaboration's Review Manager 5.3. The results of the meta-analysis were expressed as hazard ratio (HR) or risk ratio (RR), with their corresponding 95% confidence interval (CI). We included results reported from six randomized controlled trials, with a total of 1,791 patients included in the primary meta-analysis. Compared to MLNS in NSCLC patients, there was no statistically significant difference in MLND on overall survival (HR = 0.77, 95% CI 0.55 to 1.08; P = 0.13). In addition, the results indicated that local recurrence rate (RR = 0.93, 95% CI 0.68 to 1.28; P = 0.67), distant metastasis rate (RR = 0.88, 95% CI 0.74 to 1.04; P = 0.15), and total complications rate (RR = 1.10, 95% CI 0.67 to 1.79; P = 0.72) were similar, no significant difference found between the two groups. Results for overall survival, local recurrence rate, and distant metastasis rate were similar between MLND and MLNS in early stage NSCLC patients. There was no evidence that MLND increased complications compared with MLNS. Whether or not MLND is superior to MLNS for stage II-IIIA remains to be determined.

Psychotherapy for chronic major depression and dysthymia: A meta analysis

NARCIS (Netherlands)

Cuijpers, P.; van Straten, A.; Schuurmans, J.; van Oppen, P.C.; Hollon, S.D.; Andersson, G.

2010-01-01

Although several studies have examined the effects of psychotherapy on chronic depression and dysthymia, no meta-analysis has been conducted to integrate results of these studies. We conducted a meta-analysis of 16 randomized trials examining the effects of psychotherapy on chronic depression and

Psychotherapy for chronic major depression and dysthymia: A meta analysis.

NARCIS (Netherlands)

Cuijpers, P.; van Straten, A.; Schuurmans, J.; van Oppen, P.C.; Hollon, S.D.; Andersson, G.

2009-01-01

Although several studies have examined the effects of psychotherapy on chronic depression and dysthymia, no meta-analysis has been conducted to integrate results of these studies. We conducted a meta-analysis of 16 randomized trials examining the effects of psychotherapy on chronic depression and

MetaGOmics: A Web-Based Tool for Peptide-Centric Functional and Taxonomic Analysis of Metaproteomics Data.

Science.gov (United States)

Riffle, Michael; May, Damon H; Timmins-Schiffman, Emma; Mikan, Molly P; Jaschob, Daniel; Noble, William Stafford; Nunn, Brook L

2017-12-27

Metaproteomics is the characterization of all proteins being expressed by a community of organisms in a complex biological sample at a single point in time. Applications of metaproteomics range from the comparative analysis of environmental samples (such as ocean water and soil) to microbiome data from multicellular organisms (such as the human gut). Metaproteomics research is often focused on the quantitative functional makeup of the metaproteome and which organisms are making those proteins. That is: What are the functions of the currently expressed proteins? How much of the metaproteome is associated with those functions? And, which microorganisms are expressing the proteins that perform those functions? However, traditional protein-centric functional analysis is greatly complicated by the large size, redundancy, and lack of biological annotations for the protein sequences in the database used to search the data. To help address these issues, we have developed an algorithm and web application (dubbed "MetaGOmics") that automates the quantitative functional (using Gene Ontology) and taxonomic analysis of metaproteomics data and subsequent visualization of the results. MetaGOmics is designed to overcome the shortcomings of traditional proteomics analysis when used with metaproteomics data. It is easy to use, requires minimal input, and fully automates most steps of the analysis-including comparing the functional makeup between samples. MetaGOmics is freely available at https://www.yeastrc.org/metagomics/.

Hydropower externalities: a meta analysis

NARCIS (Netherlands)

Mattmann, M.; Logar, I.; Brouwer, R.

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

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

Exercise and Bone Density: Meta-Analysis

National Research Council Canada - National Science Library

Kelley, George A; Sharpe-Kelley, Kristi

2007-01-01

.... Since no meta-analysis had existed using individual patient data (IPD) to examine the effects of exercise on BMD, our second two-year period of funding was devoted to examining the feasibility...

The Flynn Effect: A Meta-analysis

Science.gov (United States)

Trahan, Lisa; Stuebing, Karla K.; Hiscock, Merril K.; Fletcher, Jack M.

2014-01-01

The “Flynn effect” refers to the observed rise in IQ scores over time, resulting in norms obsolescence. Although the Flynn effect is widely accepted, most approaches to estimating it have relied upon “scorecard” approaches that make estimates of its magnitude and error of measurement controversial and prevent determination of factors that moderate the Flynn effect across different IQ tests. We conducted a meta-analysis to determine the magnitude of the Flynn effect with a higher degree of precision, to determine the error of measurement, and to assess the impact of several moderator variables on the mean effect size. Across 285 studies (N = 14,031) since 1951 with administrations of two intelligence tests with different normative bases, the meta-analytic mean was 2.31, 95% CI [1.99, 2.64], standard score points per decade. The mean effect size for 53 comparisons (N = 3,951) (excluding three atypical studies that inflate the estimates) involving modern (since 1972) Stanford-Binet and Wechsler IQ tests (2.93, 95% CI [2.3, 3.5], IQ points per decade) was comparable to previous estimates of about 3 points per decade, but not consistent with the hypothesis that the Flynn effect is diminishing. For modern tests, study sample (larger increases for validation research samples vs. test standardization samples) and order of administration explained unique variance in the Flynn effect, but age and ability level were not significant moderators. These results supported previous estimates of the Flynn effect and its robustness across different age groups, measures, samples, and levels of performance. PMID:24979188

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.

The efficacy of dexamethasone reducing postoperative pain and emesis after total knee arthroplasty: A systematic review and meta-analysis.

Science.gov (United States)

Fan, Zhengrui; Ma, Jianxiong; Kuang, Mingjie; Zhang, Lukai; Han, Biao; Yang, Baocheng; Wang, Ying; Ma, Xinlong

2018-04-01

Total knee arthroplasty (TKA) is gradually emerging as the treatment of choice for end-stage osteoarthritis. In the past, Perioperative dexamethasone treatment is still a controversial subject in total knee arthroplasty. Therefore, we write this systematic review and meta-analysis to evaluate the efficacy of dexamethasone on pain and recovery after Total knee Arthroplasty. Embase, Pubmed, and Cochrane Library were comprehensively searched. Randomized controlled trials, cohort studies were included in our meta-analysis. Eight studies that compared dexamethasone groups with placebo groups were included in our meta-analysis. The research was reported according to the preferred reporting items for systematic reviews and meta-analysis (PRISMA) guidelines. Randomized controlled trials were included in our meta-analysis. Our study demonstrated that the dexamethasone group was more effective than the placebo group in term of VAS score at 24 h(P meta-analysis demonstrated that dexamethasone decreased postoperative pain, the incidence of POVN, and total opioid consumption effectively which played a critical role in rapid recovery to TKA. However, we still need large sample size, high quality studies to explore the relationship between complications and dose response to give the final conclusion. Copyright © 2018. Published by Elsevier Ltd.

Association between individual differences in non-symbolic number acuity and math performance: a meta-analysis.

Science.gov (United States)

Chen, Qixuan; Li, Jingguang

2014-05-01

Many recent studies have examined the association between number acuity, which is the ability to rapidly and non-symbolically estimate the quantity of items appearing in a scene, and symbolic math performance. However, various contradictory results have been reported. To comprehensively evaluate the association between number acuity and symbolic math performance, we conduct a meta-analysis to synthesize the results observed in previous studies. First, a meta-analysis of cross-sectional studies (36 samples, N = 4705) revealed a significant positive correlation between these skills (r = 0.20, 95% CI = [0.14, 0.26]); the association remained after considering other potential moderators (e.g., whether general cognitive abilities were controlled). Moreover, a meta-analysis of longitudinal studies revealed 1) that number acuity may prospectively predict later math performance (r = 0.24, 95% CI = [0.11, 0.37]; 6 samples) and 2) that number acuity is retrospectively correlated to early math performance as well (r = 0.17, 95% CI = [0.07, 0.26]; 5 samples). In summary, these pieces of evidence demonstrate a moderate but statistically significant association between number acuity and math performance. Based on the estimated effect sizes, power analyses were conducted, which suggested that many previous studies were underpowered due to small sample sizes. This may account for the disparity between findings in the literature, at least in part. Finally, the theoretical and practical implications of our meta-analytic findings are presented, and future research questions are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

Meta-analysis in plant pathology: synthesizing research results.

Science.gov (United States)

Rosenberg, M S; Garrett, K A; Su, Z; Bowden, R L

2004-09-01

ABSTRACT Meta-analysis is a set of statistical procedures for synthesizing research results from a number of different studies. An estimate of a statistical effect, such as the difference in disease severity for plants with or without a management treatment, is collected from each study along with a measure of the variance of the estimate of the effect. Combining results from different studies will generally result in increased statistical power so that it is easier to detect small effects. Combining results from different studies may also make it possible to compare the size of the effect as a function of other predictor variables such as geographic region or pathogen species. We present a review of the basic methodology for meta-analysis. We also present an example of meta-analysis of the relationship between disease severity and yield loss for foliar wheat diseases, based on data collected from a decade of fungicide and nematicide test results.

Basal cortisol levels and metabolic syndrome: A systematic review and meta-analysis of observational studies.

Science.gov (United States)

Garcez, Anderson; Leite, Heloísa Marquardt; Weiderpass, Elisabete; Paniz, Vera Maria Vieira; Watte, Guilherme; Canuto, Raquel; Olinto, Maria Teresa Anselmo

2018-05-17

To perform a qualitative synthesis (systematic review) and quantitative analysis (meta-analysis) to summarize the evidence regarding the relationship between basal cortisol levels and metabolic syndrome (MetS) in adults. A systematic search was performed in the PubMed, Embase, and PsycINFO databases for observational studies on the association between basal cortisol levels and MetS. The quality of individual studies was assessed by the Newcastle-Ottawa score. A random effects model was used to report pooled quantitative results and the I 2 statistic was used to assess heterogeneity. Egger's and Begg's tests were used to evaluate publication bias. Twenty-six studies (19 cross-sectional and seven case-control) met the inclusion criteria for the systematic review. The majority was classified as having a low risk of bias and used established criteria for the diagnosis of MetS. Twenty-one studies provided data on basal cortisol levels as continuous values and were included in the meta-analysis; they comprised 35 analyses and 11,808 subjects. Pooled results showed no significant difference in basal cortisol levels between subjects with and without MetS (standardized mean difference [SMD] = 0.02, 95% confidence interval [CI]=-0.11 to 0.14). There was high heterogeneity between the studies when all comparisons were considered (I 2  = 83.1%;p meta-analysis of studies evaluating saliva samples showed no significantly lower basal cortisol levels among subjects with MetS (SMD=-0.18, 95% CI=-0.37 to 0.01), whereas those studies that evaluated serum samples (SMD = 0.11, 95% CI=-0.02 to 0.24) and urine samples (SMD = 0.73, 95% CI=-0.40 to 1.86) showed no significantly higher basal cortisol levels among subjects with MetS. In the subgroup and meta-regression analyses, a significant difference in basal cortisol levels was observed according to study design, population base, age, gender, cortisol level assessment method, and study quality. This systematic review

Cholelithiasis, cholecystectomy and risk of hepatocellular carcinoma: A meta-analysis

Directory of Open Access Journals (Sweden)

Lingyun Guo

2014-01-01

Full Text Available Available evidence of the relationship between cholelithiasis, cholecystectomy, and risk of liver cancer and hence we conducted a meta-analysis to investigate the relationships. PubMed, EMBASE, and ISI Web of Knowledge were searched to identify all published cohort studies and case-control studies that evaluated the relationships of cholelithiasis, cholecystectomy and risk of liver cancer and single-cohort studies which evaluated the incidence of liver cancer among patients who understood cholecystectomy (up to February 2013. Comprehensive meta-analysis software was used for meta-analysis. A total of 11 observational studies (six cohort studies and five case-control studies were included in this meta-analysis. The result from meta-analysis showed that cholecystectomy (risk ratio [RR]: 1.59, 95% confidence interval [CI]: 1.01-2.51, I2 = 72% and cholecystolithiasis (RR: 5.40, 95% CI: 3.69-7.89, I2 = 93% was associated with more liver cancer, especially for intrahepatic cholangiocarcinoma (ICC (cholecystectomy: RR: 3.51, 95% CI: 1.84-6.71, I2 = 26%; cholecystolithiasis: RR: 11.06, 95% CI: 6.99-17.52, I2 = 0%. The pooled standardized incidence rates (SIR of liver cancer in patients who understood cholecystectomy showed cholecystectomy might increase the incidence of liver cancer (SIR: 1.57, 95% CI: 1.13-2.20, I2 = 15%. Based on the results of the meta-analysis, cholecystectomy and cholecystolithiasis seemed to be involved in the development of liver cancer, especially for ICC. However, most available studies were case-control studies and short-term cohort studies, so the future studies should more long-term cohort studies should be well-conducted to evaluate the long-term relationship.

Decreased serum pyridoxal levels in schizophrenia: meta-analysis and Mendelian randomization analysis

Science.gov (United States)

Tomioka, Yukiko; Kinoshita, Makoto; Umehara, Hidehiro; Watanabe, Shin-ya; Nakataki, Masahito; Iwayama, Yoshimi; Toyota, Tomoko; Ikeda, Masashi; Yamamori, Hidenaga; Shimodera, Shinji; Tajima, Atsushi; Hashimoto, Ryota; Iwata, Nakao; Yoshikawa, Takeo; Ohmori, Tetsuro

2018-01-01

Background Alterations in one-carbon metabolism have been associated with schizophrenia, and vitamin B6 is one of the key components in this pathway. Methods We first conducted a case–control study of serum pyridoxal levels and schizophrenia in a large Japanese cohort (n = 1276). Subsequently, we conducted a meta-analysis of association studies (n = 2125). Second, we investigated whether rs4654748, which was identified in a genome-wide association study as a vitamin B6-related single nucleotide polymorphism, was genetically implicated in patients with schizophrenia in the Japanese population (n = 10 689). Finally, we assessed the effect of serum pyridoxal levels on schizophrenia risk using a Mendelian randomization (MR) approach. Results Serum pyridoxal levels were significantly lower in patients with schizophrenia than in controls, not only in our cohort, but also in the pooled data set of the meta-analysis of association studies (standardized mean difference −0.48, 95% confidence interval [CI] −0.57 to −0.39, p = 9.8 × 10−24). We failed to find a significant association between rs4654748 and schizophrenia. Furthermore, an MR analysis failed to find a causal relationship between pyridoxal levels and schizophrenia risk (odds ratio 0.99, 95% CI 0.65–1.51, p = 0.96). Limitations Food consumption and medications may have affected serum pyridoxal levels in our cross-sectional study. Sample size, number of instrumental variables and substantial heterogeneity among patients with schizophrenia are limitations of an MR analysis. Conclusion We found decreased serum pyridoxal levels in patients with schizophrenia in this observational study. However, we failed to obtain data supporting a causal relationship between pyridoxal levels and schizophrenia risk using the MR approach. PMID:29688875

Association between Hypertension and Epistaxis: Systematic Review and Meta-analysis.

Science.gov (United States)

Min, Hyun Jin; Kang, Hyun; Choi, Geun Joo; Kim, Kyung Soo

2017-12-01

Objective Whether there is an association or a cause-and-effect relationship between epistaxis and hypertension is a subject of longstanding controversy. The objective of this systematic review and meta-analysis was to determine the association between epistaxis and hypertension and to verify whether hypertension is an independent risk factor of epistaxis. Data Sources A comprehensive search was performed using the MEDLINE, EMBASE, and Cochrane Library databases. Review Methods The review was performed according to the Meta-analysis of Observational Studies in Epidemiology guidelines and reported using the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines. Results We screened 2768 unique studies and selected 10 for this meta-analysis. Overall, the risk of epistaxis was significantly increased for patients with hypertension (odds ratio, 1.532 [95% confidence interval (CI), 1.181-1.986]; number needed to treat, 14.9 [95% CI, 12.3-19.0]). Results of the Q test and I 2 statistics suggested considerable heterogeneity ([Formula: see text] = 0.038, I 2 = 49.3%). The sensitivity analysis was performed by excluding 1 study at a time, and it revealed no change in statistical significance. Conclusion Although this meta-analysis had some limitations, our study demonstrated that hypertension was significantly associated with the risk of epistaxis. However, since this association does not support a causal relationship between hypertension and epistaxis, further clinical trials with large patient populations will be required to determine the impact of hypertension on epistaxis.

Caffeine ingestion enhances Wingate performance: a meta-analysis.

Science.gov (United States)

Grgic, Jozo

2018-03-01

The positive effects of caffeine ingestion on aerobic performance are well-established; however, recent findings are suggesting that caffeine ingestion might also enhance components of anaerobic performance. A commonly used test of anaerobic performance and power output is the 30-second Wingate test. Several studies explored the effects of caffeine ingestion on Wingate performance, with equivocal findings. To elucidate this topic, this paper aims to determine the effects of caffeine ingestion on Wingate performance using meta-analytic statistical techniques. Following a search through PubMed/MEDLINE, Scopus, and SportDiscus ® , 16 studies were found meeting the inclusion criteria (pooled number of participants = 246). Random-effects meta-analysis of standardized mean differences (SMD) for peak power output and mean power output was performed. Study quality was assessed using the modified version of the PEDro checklist. Results of the meta-analysis indicated a significant difference (p = .005) between the placebo and caffeine trials on mean power output with SMD values of small magnitude (0.18; 95% confidence interval: 0.05, 0.31; +3%). The meta-analysis performed for peak power output indicated a significant difference (p = .006) between the placebo and caffeine trials (SMD = 0.27; 95% confidence interval: 0.08, 0.47 [moderate magnitude]; +4%). The results from the PEDro checklist indicated that, in general, studies are of good and excellent methodological quality. This meta-analysis adds on to the current body of evidence showing that caffeine ingestion can also enhance components of anaerobic performance. The results presented herein may be helpful for developing more efficient evidence-based recommendations regarding caffeine supplementation.

Effectiveness of Mobile Devices on Vocabulary Learning: A Meta-Analysis

Science.gov (United States)

Mahdi, Hassan Saleh

2018-01-01

Mobile devices are considered as the most widely used information and communication technologies. They have provided great advantages in language learning. This study reports a meta-analysis of the effectiveness of using mobile devices on vocabulary learning. A meta-analysis was conducted on research that compared the outcomes from students…

The Impact of Uncertainty on Investment. A Meta-Analysis

Energy Technology Data Exchange (ETDEWEB)

Koetse, M.J. [Department of Spatial Economics, Vrije Universiteit Amsterdam (Netherlands); De Groot, Henri L.F. [Tinbergen Institute, Amsterdam (Netherlands); Florax, R.J.G.M. [Department of Agricultural Economics, Purdue University, West Lafayette (United States)

2006-07-01

In this paper we perform a meta-analysis on empirical estimates of the impact between investment and uncertainty. Since the outcomes of primary studies are largely incomparable with respect to the magnitude of the effect, our analysis focuses on the direction and statistical significance of the relationship. The standard approach in this situation is to estimate an ordered probit model on a categorical estimate, defined in terms of the direction of the effect. The estimates are transformed into marginal effects, in order to represent the changes in the probability of finding a negative significant, insignificant, and positive significant estimate. Although a meta-analysis generally does not allow for inferences on the correctness of model specifications in primary studies, our results give clear directions for model building in empirical investment research. For example, not including factor prices in investment models may seriously affect the model outcomes. Furthermore, we find that Q models produce more negative significant estimates than other models do, ceteris paribus. The outcome of a study is also affected by the type of data used in a primary study. Although it is clear that meta-analysis cannot always give decisive insights into the explanations for the variation in empirical outcomes, our meta-analysis shows that we can explain to a large extent why empirical estimates of the investment uncertainty relationship differ.

Low birth weight and intelligence in adolescence and early adulthood: a meta-analysis.

Science.gov (United States)

Kormos, C E; Wilkinson, A J; Davey, C J; Cunningham, A J

2014-06-01

Research has demonstrated an association between low birth weight (LBW; intelligence quotient (IQ) outcomes in childhood and early adolescence. We systematically evaluated whether this association persists into late adolescence and early adulthood and also assessed the influence of age of IQ assessment on effect size. During Stage 1 (meta-analysis of data on adolescents/adults), we searched for relevant articles in PsychINFO, PubMed, Ovid, CINAHL, ProQuest and ERIC until February 2011 (no lower limit). Studies which assessed full-scale IQ among LBW individuals (analysis provided a pooled estimate of the difference in IQ scores between LBW and NBW individuals. Publication bias was assessed using Rosenthal's classic fail-safe N and Duval and Tweedie's Trim and Fill. During Stage 2, we added data from the Kerr-Wilson et al. meta-analysis (which included data from children; in Meta-analysis of the association between preterm delivery and intelligence. Journal Public Health 2011;33:1-8) to our sample from Stage 1 and conducted a meta-regression to evaluate the effect of age of IQ assessment. Using a total of 15 studies in Stage 1, it was demonstrated that NBW individuals scored an average of 7.63 IQ points higher than LBW individuals, CI = 5.95-9.31. After adjusting for publication bias, NBW samples demonstrated an IQ of 4.98 points higher than LBW samples, CI = 3.20-6.77. Furthermore, age at IQ assessment was a significant moderator of the association between birth weight and IQ, in that the effect size decreased from childhood into young adulthood. Cognitive impairments associated with LBW persist into adolescence and early adulthood; however, the influence of LBW on IQ decreases from childhood to young adulthood. These conclusions must be interpreted with caution due to unmeasured variables and possible influence from publication bias. © The Author 2013. Published by Oxford University Press on behalf of Faculty of Public Health. All rights reserved. For permissions

Physical Readiness Training: A Meta-Analysis

National Research Council Canada - National Science Library

Vickers, Jr, Ross R

2007-01-01

.... This meta-analysis of available PRT studies (k = 3) indicated that (a) Fitness gains in the PRT program were equal to the gains in traditional fitness programs, and (b) the injury rate (i.e., hazard ratio...

Energy consumption and economic growth—New evidence from meta analysis

International Nuclear Information System (INIS)

Chen, Ping-Yu; Chen, Sheng-Tung; Chen, Chi-Chung

2012-01-01

The causal relationships between energy consumption and economic growth have given rise to much discussion but remain controversial. Alternative data sets based on different time spans, countries, energy policies and econometric approaches result in diverse outcomes. A meta analysis using a multinomial logit model with 174 samples governing the relationships between GDP and energy consumption is applied here to investigate the major factors that affect these controversial outcomes. The empirical results have demonstrated how the time spans, subject selections including GDP and energy consumption, econometric models, and tools for greenhouse gases emission reduction characteristics significantly affect these controversial outcomes. - Highlights: ► The controversial casual relationships between energy consumption and GDP are investigated. ► A meta analysis using a multinomial logit model is adopted. ► 74 studies governing the relationships between GDP and energy consumption was collected. ► The empirical results show how the probability of major factors affects such relationships.

MADAM - An open source meta-analysis toolbox for R and Bioconductor

Directory of Open Access Journals (Sweden)

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.

Reference values for muscle strength: a systematic review with a descriptive meta-analysis.

Science.gov (United States)

Benfica, Poliana do Amaral; Aguiar, Larissa Tavares; Brito, Sherindan Ayessa Ferreira de; Bernardino, Luane Helena Nunes; Teixeira-Salmela, Luci Fuscaldi; Faria, Christina Danielli Coelho de Morais

2018-05-03

Muscle strength is an important component of health. To describe and evaluate the studies which have established the reference values for muscle strength on healthy individuals and to synthesize these values with a descriptive meta-analysis approach. A systematic review was performed in MEDLINE, LILACS, and SciELO databases. Studies that investigated the reference values for muscle strength of two or more appendicular/axial muscle groups of health individuals were included. Methodological quality, including risk of bias was assessed by the QUADAS-2. Data extracted included: country of the study, sample size, population characteristics, equipment/method used, and muscle groups evaluated. Of the 414 studies identified, 46 were included. Most of the studies had adequate methodological quality. Included studies evaluated: appendicular (80.4%) and axial (36.9%) muscles; adults (78.3%), elderly (58.7%), adolescents (43.5%), children (23.9%); isometric (91.3%) and isokinetic (17.4%) strength. Six studies (13%) with similar procedures were synthesized with meta-analysis. Generally, the coefficient of variation values that resulted from the meta-analysis ranged from 20.1% to 30% and were similar to those reported by the original studies. The meta-analysis synthesized the reference values of isometric strength of 14 muscle groups of the dominant/non-dominant sides of the upper/lower limbs of adults/elderly from developed countries, using dynamometers/myometer. Most of the included studies had adequate methodological quality. The meta-analysis provided reference values for the isometric strength of 14 appendicular muscle groups of the dominant/non-dominant sides, measured with dynamometers/myometers, of men/women, of adults/elderly. These data may be used to interpret the results of the evaluations and establish appropriate treatment goals. Copyright © 2018 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights

The universality of childhood emotional abuse: A meta-analysis of worldwide prevalence

NARCIS (Netherlands)

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

2012-01-01

This comprehensive meta-analysis combined prevalence figures of child emotional abuse reported in 29 studies, including 46 independent samples with a total of 7,082,279 participants. The overall estimated prevalence was 3/1,000 for studies using informants and 363/1,000 for studies using self-report

Temporal trends in sperm count: a systematic review and meta-regression analysis.

Science.gov (United States)

Levine, Hagai; Jørgensen, Niels; Martino-Andrade, Anderson; Mendiola, Jaime; Weksler-Derri, Dan; Mindlis, Irina; Pinotti, Rachel; Swan, Shanna H

2017-11-01

Reported declines in sperm counts remain controversial today and recent trends are unknown. A definitive meta-analysis is critical given the predictive value of sperm count for fertility, morbidity and mortality. To provide a systematic review and meta-regression analysis of recent trends in sperm counts as measured by sperm concentration (SC) and total sperm count (TSC), and their modification by fertility and geographic group. PubMed/MEDLINE and EMBASE were searched for English language studies of human SC published in 1981-2013. Following a predefined protocol 7518 abstracts were screened and 2510 full articles reporting primary data on SC were reviewed. A total of 244 estimates of SC and TSC from 185 studies of 42 935 men who provided semen samples in 1973-2011 were extracted for meta-regression analysis, as well as information on years of sample collection and covariates [fertility group ('Unselected by fertility' versus 'Fertile'), geographic group ('Western', including North America, Europe Australia and New Zealand versus 'Other', including South America, Asia and Africa), age, ejaculation abstinence time, semen collection method, method of measuring SC and semen volume, exclusion criteria and indicators of completeness of covariate data]. The slopes of SC and TSC were estimated as functions of sample collection year using both simple linear regression and weighted meta-regression models and the latter were adjusted for pre-determined covariates and modification by fertility and geographic group. Assumptions were examined using multiple sensitivity analyses and nonlinear models. SC declined significantly between 1973 and 2011 (slope in unadjusted simple regression models -0.70 million/ml/year; 95% CI: -0.72 to -0.69; P regression analysis reports a significant decline in sperm counts (as measured by SC and TSC) between 1973 and 2011, driven by a 50-60% decline among men unselected by fertility from North America, Europe, Australia and New Zealand. Because

A meta-analysis of cerebrovascular disease and hyperhomocysteinaemia

DEFF Research Database (Denmark)

Nielsen, G M; Tvedegaard, K C; Andersen, Niels Trolle

2000-01-01

Hyperhomocysteinaemia has been identified as a risk factor for stroke and cerebrovascular disease in several studies. To evaluate the evidence we performed a meta-analysis. We found 21 studies searching Medline from 1966-July 1999 using the key words homocysteine, homocystine and cerebrovascular...... was used. The reports on 8 cross-sectional and 4 longitudinal studies gave data on the mean and standard deviations of plasma or serum homocysteine for both cases and controls, and these studies were included in the meta-analysis. The results of the 5 excluded studies all pointed to a positive relationship...

The prevalence of food allergy: A meta-analysis

DEFF Research Database (Denmark)

Rona, Roberto J.; Keil, Thomas; Summers, Colin

2007-01-01

Background: There is uncertainty about the prevalence of food allergy in communities. Objective: To assess the prevalence of food allergy by performing a meta-analysis according to the method of assessment used. Methods: The foods assessed were cow's milk, hen's egg, peanut, fish, shellfish....... The meta-analysis included only original studies. They were stratified by age groups: infant/preschool, school children, and adults. Results: A total of 934 articles were identified, but only 51 were considered appropriate for inclusion. The prevalence of self-reported food allergy was very high compared...

A Systematic Review and Meta-analysis of Childhood Health Utilities.

Science.gov (United States)

Kwon, Joseph; Kim, Sung Wook; Ungar, Wendy J; Tsiplova, Kate; Madan, Jason; Petrou, Stavros

2018-04-01

A common feature of most reviews or catalogues of health utilities has been their focus on adult health states or derivation of values from adult populations. More generally, utility measurement in or on behalf of children has been constrained by several methodological concerns. The objective of this study was to conduct the first comprehensive systematic review and meta-analysis of primary utility data for childhood conditions and descriptors, and to determine the effects of methodological factors on childhood utilities. The review followed PRISMA guidelines. PubMed, Embase, Web of Science, PsycINFO, EconLit, CINAHL and Cochrane Library were searched for primary studies reporting health utilities for childhood conditions or descriptors using direct or indirect valuation methods. The Paediatric Economic Database Evaluation (PEDE) Porject was also searched for cost-utility analyses with primary utility values. Mean or median utilities for each of the main samples were catalogued, and weighted averages of utilities for each health condition were estimated, by valuation method. Mixed-effects meta-regression using hierarchical linear modeling was conducted for the most common valuation methods to estimate the utility decrement for each health condition category relative to general childhood population health, as well as the independent effects of methodological factors. The literature searches resulted in 272 eligible studies. These yielded 3,414 utilities when all sub-groups were considered, covering all ICD-10 chapters relevant to childhood health, 19 valuation methods, 12 respondent types, 8 modes of administration, and data from 36 countries. A total of 1,191 utility values were obtained when only main study samples were considered, and these were catalogued by health condition or descriptor, and methodological characteristics. 1,073 mean utilities for main samples were used for fixed-effects meta-analysis by health condition and valuation method. Mixed

Age, the psychological contract, and job attitudes : a meta-analysis

NARCIS (Netherlands)

Bal, P. Matthijs; de Lange, Annet H.; Jansen, Paul G. W.; van der Velde, Mandy E. G.

Age, the psychological contract, and job attitudes: a meta-analysis P.M. Bal, A H. De Lange, P.G.W Jansen Er M.E G Van der Velde, Gedrag en Organisatie, volume 23, March 2010, nr 1, pp 44-72. The meta-analysis investigated the relations between age and psychological contracts It was expected that

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

MetaGOmics: A Web-Based Tool for Peptide-Centric Functional and Taxonomic Analysis of Metaproteomics Data

Directory of Open Access Journals (Sweden)

Michael Riffle

2017-12-01

Full Text Available Metaproteomics is the characterization of all proteins being expressed by a community of organisms in a complex biological sample at a single point in time. Applications of metaproteomics range from the comparative analysis of environmental samples (such as ocean water and soil to microbiome data from multicellular organisms (such as the human gut. Metaproteomics research is often focused on the quantitative functional makeup of the metaproteome and which organisms are making those proteins. That is: What are the functions of the currently expressed proteins? How much of the metaproteome is associated with those functions? And, which microorganisms are expressing the proteins that perform those functions? However, traditional protein-centric functional analysis is greatly complicated by the large size, redundancy, and lack of biological annotations for the protein sequences in the database used to search the data. To help address these issues, we have developed an algorithm and web application (dubbed “MetaGOmics” that automates the quantitative functional (using Gene Ontology and taxonomic analysis of metaproteomics data and subsequent visualization of the results. MetaGOmics is designed to overcome the shortcomings of traditional proteomics analysis when used with metaproteomics data. It is easy to use, requires minimal input, and fully automates most steps of the analysis—including comparing the functional makeup between samples. MetaGOmics is freely available at https://www.yeastrc.org/metagomics/.

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.

Meta-analysis of the relationship between TQM and Business Performance

International Nuclear Information System (INIS)

Ahmad M F; Zakuan N; Jusoh A; Tasir Z; Takala J

2013-01-01

Meta-analysis has been conducted based on 20 previous works from 4,040 firms at 16 countries from Asia, Europe and America. Throughout this paper a meta-analysis, this paper reviews the relationships between TQM and business performance amongst the regions. Meta-analysis result concludes that the average of rc is 0.47; Asia (rc=0.54), America (rc=0.43) and Europe (rc=0.38). The analysis also shows that Asia developed countries have greatest impact of TQM (rc=0.56). However, the analysis of ANOVA and t-test show that there is no significant difference amongst type of country (developed and developing countries) and regions at p=0.05. In addition, the average result of rc 2 is 0.24; Asia (rc 2 =0.33), America (rc 2 =0.22) and Europe (rc 2 =0.15). Meanwhile, rc 2 in developing countries (rc 2 =0.28) are higher than developed countries (rc 2 =0.21).

Creativity and Academic Achievement: A Meta-Analysis

Science.gov (United States)

Gajda, Aleksandra; Karwowski, Maciej; Beghetto, Ronald A.

2017-01-01

This article reports on a meta-analysis of 120 studies (total N = 52,578; 782 effects) examining the relationship between creativity and academic achievement in research conducted since the 1960s. Average correlation between creativity and academic achievement was r = 0.22, 95% CI [0.19, 0.24]. An analysis of moderators revealed that this…

Lead and Conduct Problems: A Meta-Analysis

Science.gov (United States)

Marcus, David K.; Fulton, Jessica J.; Clarke, Erin J.

2010-01-01

This meta-analysis examined the association between conduct problems and lead exposure. Nineteen studies on 8,561 children and adolescents were included. The average "r" across all 19 studies was 0.19 (p less than 0.001), which is considered a medium effect size. Studies that assessed lead exposure using hair element analysis yielded…

Radiosurgery of Glomus Jugulare Tumors: A Meta-Analysis

International Nuclear Information System (INIS)

Guss, Zachary D.; Batra, Sachin; Limb, Charles J.; Li, Gordon; Sughrue, Michael E.; Redmond, Kristin; Rigamonti, Daniele; Parsa, Andrew T.; Chang, Steven; Kleinberg, Lawrence; Lim, Michael

2011-01-01

Purpose: During the past two decades, radiosurgery has arisen as a promising approach to the management of glomus jugulare. In the present study, we report on a systematic review and meta-analysis of the available published data on the radiosurgical management of glomus jugulare tumors. Methods and Materials: To identify eligible studies, systematic searches of all glomus jugulare tumors treated with radiosurgery were conducted in major scientific publication databases. The data search yielded 19 studies, which were included in the meta-analysis. The data from 335 glomus jugulare patients were extracted. The fixed effects pooled proportions were calculated from the data when Cochrane's statistic was statistically insignificant and the inconsistency among studies was 36 months. In these studies, 95% of patients achieved clinical control and 96% achieved tumor control. The gamma knife, linear accelerator, and CyberKnife technologies all exhibited high rates of tumor and clinical control. Conclusions: The present study reports the results of a meta-analysis for the radiosurgical management of glomus jugulare. Because of its high effectiveness, we suggest considering radiosurgery for the primary management of glomus jugulare tumors.

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.

Systematic review, meta-analysis, and meta-regression: Successful second-line treatment for Helicobacter pylori.

Science.gov (United States)

Muñoz, Neus; Sánchez-Delgado, Jordi; Baylina, Mireia; Puig, Ignasi; López-Góngora, Sheila; Suarez, David; Calvet, Xavier

2018-06-01

Multiple Helicobacter pylori second-line schedules have been described as potentially useful. It remains unclear, however, which are the best combinations, and which features of second-line treatments are related to better cure rates. The aim of this study was to determine that second-line treatments achieved excellent (>90%) cure rates by performing a systematic review and when possible a meta-analysis. A meta-regression was planned to determine the characteristics of treatments achieving excellent cure rates. A systematic review for studies evaluating second-line Helicobacter pylori treatment was carried out in multiple databases. A formal meta-analysis was performed when an adequate number of comparative studies was found, using RevMan5.3. A meta-regression for evaluating factors predicting cure rates >90% was performed using Stata Statistical Software. The systematic review identified 115 eligible studies, including 203 evaluable treatment arms. The results were extremely heterogeneous, with 61 treatment arms (30%) achieving optimal (>90%) cure rates. The meta-analysis favored quadruple therapies over triple (83.2% vs 76.1%, OR: 0.59:0.38-0.93; P = .02) and 14-day quadruple treatments over 7-day treatments (91.2% vs 81.5%, OR; 95% CI: 0.42:0.24-0.73; P = .002), although the differences were significant only in the per-protocol analysis. The meta-regression did not find any particular characteristics of the studies to be associated with excellent cure rates. Second-line Helicobacter pylori treatments achieving>90% cure rates are extremely heterogeneous. Quadruple therapy and 14-day treatments seem better than triple therapies and 7-day ones. No single characteristic of the treatments was related to excellent cure rates. Future approaches suitable for infectious diseases-thus considering antibiotic resistances-are needed to design rescue treatments that consistently achieve excellent cure rates. © 2018 John Wiley & Sons Ltd.

A systematic review and meta-analysis of the circulatory, erythrocellular and CSF selenium levels in Alzheimer's disease: A metal meta-analysis (AMMA study-I).

Science.gov (United States)

Reddy, Varikasuvu Seshadri; Bukke, Suman; Dutt, Naveen; Rana, Puneet; Pandey, Arun Kumar

2017-07-01

Available studies in the literature on the selenium levels in Alzheimer's disease (AD) are inconsistent with some studies reporting its decrease in the circulation, while others reported an increase or no change as compared to controls. The objective of this study was to perform a meta-analysis of circulatory (plasma/serum and blood), erythrocyte and cerebrospinal fluid (CSF) selenium levels in AD compared controls. We also performed a meta-analysis of the correlation coefficients (r) to demonstrate the associations between selenium and glutathione peroxidase (GPx) in AD patients. All major databases were searched for eligible studies. We included 12 case-control/observational studies reporting selenium concentrations in AD and controls. Pooled-overall effect size as standardized mean difference (SMD) and pooled r-values were generated using Review Manager 5.3 and MedCalc 15.8 software. Random-effects meta-analysis indicated a decrease in circulatory (SMD=-0.44), erythrocellular (SMD=-0.52) and CSF (SMD=-0.14) selenium levels in AD patients compared to controls. Stratified meta-analysis demonstrated that the selenium levels were decreased in both the subgroups with (SMD=-0.55) and without (SMD=-0.37) age matching between AD and controls. Our results also demonstrated a direct association between decreased selenium levels and GPx in AD. This meta-analysis suggests that circulatory selenium concentration is significantly lower in AD patients compared to controls and this decrease in selenium is directly correlated with an important antioxidant enzyme, the GPx, in AD. Copyright © 2017 Elsevier GmbH. All rights reserved.

Mismatch Negativity in Han Chinese Patients with Schizophrenia: A Meta-Analysis.

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Xiong, Yanbing; Ll, Xianbin; Zhao, Lei; Wang, Chuanyue

2017-10-25

Previous meta-analysis revealed that mismatch negativity(MMN) amplitude decreased in patients with schizophrenia compared with healthy controls (Cohen's d, d about 1), leading to the possibility of mismatch negativity being used as a biomarker for schizophrenia. However, it is unknown whether MMN is reliably changed in Chinese patients. It is necessary to carry out a meta-analysis on MMN of Han Chinese patients with schizophrenia. To investigate whether MMN could be used as a biomarker for Han Chinese patients with schizophrenia. A literature search was conducted to identify clinical trials on MMN in Han Chinese schizophrenia patients published before May 8, 2017, by searching the Chinese language databases CNKI, WanFang Data, VIP Data and PubMed. The effects of MMN deficits were evaluated for MMN amplitude by calculating standard mean difference (SMDs) between schizophrenia patient groups and healthy control groups. A total of 11 studies were included in the analysis. The total quality of all the studies were more than 6 as evaluated by Newcastle-Ottawa Scale (NOS). Meta-analysis of data from these studies had a pooled sample of 432 patients with schizophrenia and 392 healthy controls. There exists significant MMN deficit in schizophrenia patients compared to healthy controls (Cohen's d =1.004). When studies were excluded due to heterogeneity, the pooled effect size of the MMN differences between the patient group and healthy controls dropped to 0.79 (Cohen's d =0.79). Subgroup analysis showed that MMN amplitude deficits of schizophrenia over three years had the pooled effect size of 0.95, and less than three years had the pooled effect size of 0.77. Publication bias conducted via Egger regression test ( t = 1.83; p = 0.101), suggested that there was no publication bias. The effect size of MMN amplitude between Chinese patients with schizophrenia and healthy controls is consistent with other meta-analyses published on this topic, suggesting that Han Chinese

GetReal in network meta-analysis : a review of the methodology

NARCIS (Netherlands)

Efthimiou, Orestis; Debray, Thomas P A; van Valkenhoef, Gert; Trelle, Sven; Panayidou, Klea; Moons, Karel G M; Reitsma, Johannes B.; Shang, Aijing; Salanti, Georgia

2016-01-01

Pairwise meta-analysis is an established statistical tool for synthesizing evidence from multiple trials, but it is informative only about the relative efficacy of two specific interventions. The usefulness of pairwise meta-analysis is thus limited in real-life medical practice, where many competing

Network meta-analysis-highly attractive but more methodological research is needed

NARCIS (Netherlands)

Li, Tianjing; Puhan, Milo A.; Vedula, Swaroop S.; Singh, Sonal; Dickersin, Kay; Cameron, Chris; Goodman, Steven N.; Mills, Edward; Musch, David; ter Riet, Gerben; Robinson, Karen; Schmid, Christopher; Song, Fujian; Thorlund, Kristian; Trikalinos, Thomas

2011-01-01

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

Selenium Exposure and Cancer Risk: an Updated Meta-analysis and Meta-regression

Science.gov (United States)

Cai, Xianlei; Wang, Chen; Yu, Wanqi; Fan, Wenjie; Wang, Shan; Shen, Ning; Wu, Pengcheng; Li, Xiuyang; Wang, Fudi

2016-01-01

The objective of this study was to investigate the associations between selenium exposure and cancer risk. We identified 69 studies and applied meta-analysis, meta-regression and dose-response analysis to obtain available evidence. The results indicated that high selenium exposure had a protective effect on cancer risk (pooled OR = 0.78; 95%CI: 0.73–0.83). The results of linear and nonlinear dose-response analysis indicated that high serum/plasma selenium and toenail selenium had the efficacy on cancer prevention. However, we did not find a protective efficacy of selenium supplement. High selenium exposure may have different effects on specific types of cancer. It decreased the risk of breast cancer, lung cancer, esophageal cancer, gastric cancer, and prostate cancer, but it was not associated with colorectal cancer, bladder cancer, and skin cancer. PMID:26786590

The Neural Correlates of Moral Thinking: A Meta-Analysis

OpenAIRE

Douglas J. Bryant; Wang F; Kelley Deardeuff; Emily Zoccoli; Chang S. Nam

2016-01-01

We conducted a meta-analysis to evaluate current research that aims to map the neural correlates of two typical conditions of moral judgment: right-wrong moral judgments and decision-making in moral dilemmas. Utilizing the activation likelihood estimation (ALE) method, we conducted a meta-analysis using neuroimaging data obtained from twenty-one previous studies that measured responses in one or the other of these conditions. We found that across the studies (n = 400), distinct neural circuit...

Meta-analysis: Nitroglycerin for prevention of post-ERCP pancreatitis

DEFF Research Database (Denmark)

Nøjgaard, C; Matzen, P; Andersen, Per Kragh

2009-01-01

BACKGROUND: Acute pancreatitis after ERCP is a severe side effect. AIM: To evaluate the preventive effect of nitroglycerin on post-ERCP pancreatitis by a meta-analysis of randomized clinical studies. METHODS: We searched on Pubmed, Embase, Cochrane Library and all abstracts presented at Digestive......-ERCP pancreatitis after administration of nitroglycerin were identified. Meta-analysis including all five studies showed a relative risk (RR) of 0.61 (95% CI; 0.44, 0.86) with the number needed to treat (NNT) of 26 (95% CI: 16, 82). Three studies evaluated nitroglycerin administered by a dermal patch reaching...... together an RR of 0.66 (95% CI; 0.43, 1.01). The use of nitroglycerin is associated with a significantly increased risk of hypotension (RR 2.25) and headache (RR 3.64). No difference in mortality was observed. CONCLUSIONS: Overall, our meta-analysis supports the use of nitroglycerin in the prevention...

Guidance for the utility of linear models in meta-analysis of genetic association studies of binary phenotypes.

Science.gov (United States)

Cook, James P; Mahajan, Anubha; Morris, Andrew P

2017-02-01

Linear mixed models are increasingly used for the analysis of genome-wide association studies (GWAS) of binary phenotypes because they can efficiently and robustly account for population stratification and relatedness through inclusion of random effects for a genetic relationship matrix. However, the utility of linear (mixed) models in the context of meta-analysis of GWAS of binary phenotypes has not been previously explored. In this investigation, we present simulations to compare the performance of linear and logistic regression models under alternative weighting schemes in a fixed-effects meta-analysis framework, considering designs that incorporate variable case-control imbalance, confounding factors and population stratification. Our results demonstrate that linear models can be used for meta-analysis of GWAS of binary phenotypes, without loss of power, even in the presence of extreme case-control imbalance, provided that one of the following schemes is used: (i) effective sample size weighting of Z-scores or (ii) inverse-variance weighting of allelic effect sizes after conversion onto the log-odds scale. Our conclusions thus provide essential recommendations for the development of robust protocols for meta-analysis of binary phenotypes with linear models.

Differential Identification of Females and Males with Reading Difficulties: A Meta-Analysis

Science.gov (United States)

Quinn, Jamie M.

2018-01-01

Males are more likely than females to be identified as having reading difficulties, but it is unclear if this is a result of sample ascertainment or identification bias. The purpose of this meta-analysis was to determine the magnitude of gender differences in reading difficulties using available studies in which researchers investigated this…

MetaNetter 2: A Cytoscape plugin for ab initio network analysis and metabolite feature classification.

Science.gov (United States)

Burgess, K E V; Borutzki, Y; Rankin, N; Daly, R; Jourdan, F

2017-12-15

Metabolomics frequently relies on the use of high resolution mass spectrometry data. Classification and filtering of this data remain a challenging task due to the plethora of complex mass spectral artefacts, chemical noise, adducts and fragmentation that occur during ionisation and analysis. Additionally, the relationships between detected compounds can provide a wealth of information about the nature of the samples and the biochemistry that gave rise to them. We present a biochemical networking tool: MetaNetter 2 that is based on the original MetaNetter, a Cytoscape plugin that creates ab initio networks. The new version supports two major improvements: the generation of adduct networks and the creation of tables that map adduct or transformation patterns across multiple samples, providing a readout of compound relationships. We have applied this tool to the analysis of adduct patterns in the same sample separated under two different chromatographies, allowing inferences to be made about the effect of different buffer conditions on adduct detection, and the application of the chemical transformation analysis to both a single fragmentation analysis and an all-ions fragmentation dataset. Finally, we present an analysis of a dataset derived from anaerobic and aerobic growth of the organism Staphylococcus aureus demonstrating the utility of the tool for biological analysis. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

The correlation of social support with mental health: A meta-analysis.

Science.gov (United States)

Harandi, Tayebeh Fasihi; Taghinasab, Maryam Mohammad; Nayeri, Tayebeh Dehghan

2017-09-01

Social support is an important factor that can affect mental health. In recent decades, many studies have been done on the impact of social support on mental health. The purpose of the present study is to investigate the effect size of the relationship between social support and mental health in studies in Iran. This meta-analysis was carried out in studies that were performed from 1996 through 2015. Databases included SID and Magiran, the comprehensive portal of human sciences, Noor specialized magazine databases, IRANDOC, Proquest, PubMed, Scopus, ERIC, Iranmedex and Google Scholar. The keywords used to search these websites included "mental health or general health," and "Iran" and "social support." In total, 64 studies had inclusion criteria meta-analysis. In order to collect data used from a meta-analysis worksheet that was made by the researcher and for data analysis software, CMA-2 was used. The mean of effect size of the 64 studies in the fixed-effect model and random-effect model was obtained respectively as 0.356 and 0.330, which indicated the moderate effect size of social support on mental health. The studies did not have publication bias, and enjoyed a heterogeneous effect size. The target population and social support questionnaire were moderator variables, but sex, sampling method, and mental health questionnaire were not moderator variables. Regarding relatively high effect size of the correlation between social support and mental health, it is necessary to predispose higher social support, especially for women, the elderly, patients, workers, and students.

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.

A meta-analysis of serious digital games for healthy lifestyle promotion

Science.gov (United States)

Several systematic reviews have described health-promoting effects of serious games, but so far no meta-analysis has been reported. This paper presents a meta-analysis of 54 serious digital game studies for healthy lifestyle promotion, in which we investigated the overall effectiveness of serious di...

Contemporary management of frontal sinus mucoceles: a meta-analysis.

Science.gov (United States)

Courson, Andy M; Stankiewicz, James A; Lal, Devyani

2014-02-01

To analyze trends in the surgical management of frontal and fronto-ethmoid mucoceles through meta-analysis. Meta-analysis and case series. A systematic literature review on surgical management of frontal and fronto-ethmoid mucoceles was conducted. Studies were divided into historical (1975-2001) and contemporary (2002-2012) groups. A meta-analysis of these studies was performed. The historical and contemporary cohorts were compared (surgical approach, recurrence, and complications). To study evolution in surgical management, a senior surgeon's experience over 28 years was analyzed separately. Thirty-one studies were included for meta-analysis. The historical cohort included 425 mucoceles from 11 studies. The contemporary cohort included 542 mucoceles from 20 studies. More endoscopic techniques were used in the contemporary versus historical cohort (53.9% vs. 24.7%; P = contemporary). In the historical cohort, higher recurrence was noted in the external group (P = 0.03). Results from endoscopic and open approaches are comparable. Although endoscopic techniques are being increasingly adopted, comparison with our series shows that more cases could potentially be treated endoscopically. Frequent use of open approaches may reflect efficacy, or perhaps lack of expertise and equipment required for endoscopic management. Most contemporary authors favor endoscopic management, limiting open approaches for specific indications (unfavorable anatomy, lateral disease, and scarring). N/A. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

How to do Meta-Analysis using HLM software

OpenAIRE

Petscher, Yaacov

2013-01-01

This is a step-by-step presentation of how to run a meta-analysis using HLM software. Because it's a variance known model, it is not run through the GUI, but batch mode. These slides show how to prepare the data and run the analysis.

Fatal flaws in a recent meta-analysis on abortion and mental health.

Science.gov (United States)

Steinberg, Julia R; Trussell, James; Hall, Kelli S; Guthrie, Kate

2012-11-01

Similar to other reviews within the last 4 years, a thorough review by the Royal College of Psychiatrists, published in December 2011, found that compared to delivery of an unintended pregnancy, abortion does not increase women's risk of mental health problems. In contrast, a meta-analysis published in September 2011 concluded that abortion increases women's risk of mental health problems by 81% and that 10% of mental health problems are attributable to abortions. Like others, we strongly question the quality of this meta-analysis and its conclusions. Here we detail seven errors of this meta-analysis and three significant shortcomings of the included studies because policy, practice and the public have been misinformed. These errors and shortcomings render the meta-analysis' conclusions invalid. Copyright © 2012 Elsevier Inc. All rights reserved.

The Relationship between Juvenile Psychopathic Traits, Delinquency and (Violent) Recidivism: A Meta-Analysis

Science.gov (United States)

Asscher, Jessica J.; van Vugt, Eveline S.; Stams, Geert Jan J. M.; Dekovic, Maja; Eichelsheim, Veroni I.; Yousfi, Sarah

2011-01-01

A meta-analysis of k = 53 studies containing 60 non-overlapping samples and 10,073 participants was conducted to investigate whether psychopathy was associated with delinquency and (violent) recidivism in juveniles. The results showed that psychopathy was moderately associated with delinquency, general recidivism, and violent recidivism. Moderator…

Quality of life in autism across the lifespan: A meta-analysis

NARCIS (Netherlands)

van Heijst, B.F.C.; Geurts, H.M.

2015-01-01

Autism is a lifelong neurodevelopmental disorder, with a known impact on quality of life. Yet the developmental trajectory of quality of life is not well understood. First, the effect of age on quality of life was studied with a meta-analysis. Our meta-analysis included 10 studies (published between

Child-Centered Play Therapy in the Schools: Review and Meta-Analysis

Science.gov (United States)

Ray, Dee C.; Armstrong, Stephen A.; Balkin, Richard S.; Jayne, Kimberly M.

2015-01-01

The authors conducted a meta-analysis and systematic review that examined 23 studies evaluating the effectiveness of child centered play therapy (CCPT) conducted in elementary schools. Meta-analysis results were explored using a random effects model for mean difference and mean gain effect size estimates. Results revealed statistically significant…

A meta-analysis of the effects of dropout prevention programs on school absenteeism.

Science.gov (United States)

Tanner-Smith, Emily E; Wilson, Sandra Jo

2013-10-01

This study reports findings from a systematic review and meta-analysis of literature examining the effects of school dropout prevention and intervention programs on students' school absenteeism outcomes. The meta-analysis synthesized 74 effect sizes measuring posttest differences in school absenteeism outcomes for youth enrolled in dropout prevention programs relative to a comparison group. Although results from randomized controlled trials indicated significant beneficial program effects, findings from quasi-experimental studies indicated no significant beneficial or detrimental effects. Examination of study characteristics suggested that dropout programs may have beneficial effects on school absenteeism among primarily male samples, and younger samples. Although no single type of intervention program was consistently more effective than others, vocational oriented and supplemental academic training programs showed some promise. However, the inconsistency in results and the possibility of small study bias mean the quality of evidence in this literature is low; at this time there is not enough evidence to conclude that dropout prevention programs have a universal impact on youth's school absenteeism outcomes.

Interleukin-8 for diagnosis of neonatal sepsis: a meta-analysis.

Directory of Open Access Journals (Sweden)

Min Zhou

Full Text Available Neonatal sepsis (NS is a life-threatening disorder and an important cause of morbidity and mortality in neonates. Previous studies showed that interleukin 8 (IL-8 may effectively and rapidly diagnose NS.We conducted the systematic review and meta-analysis to investigate the diagnostic value of the IL-8 in NS.The literature was searched in PUBMED, EMBASE, Cochrane Library, CNKI, VIP and other Chinese Medical Databases during October 1998 to January 2014 using set search criteria. Each included study was evaluated by quality assessment of diagnostic accuracy studies tool. Two investigators independently extracted the data and study characteristics, and disagreements, if any, were resolved by consensus. Meta-disc software was used to calculate the pooled sensitivity, specificity and summary diagnostic odds ratio (SDOR, I² or Cochrane Q to test heterogeneity, and meta-regression to investigate the source of heterogeneity. Funnel plots were used to test the potential presence of publication bias. False-positive report probability (FPRP was calculated to confirm the significance of the results.Eight studies (548 neonates were included in this meta-analysis. The pooled sensitivity and specificity of IL-8 were 0.78 and 0.84, respectively, which had moderate accuracy in the diagnosis of NS. The pooled diagnostic odds ratio (DOR and area under curve (AUC was 21.64 and 0.8908 (Q*=0.8215, respectively. The diagnostic threshold analysis showed that there was no threshold effect. The meta-regression analysis showed the cut-off, QUADAS and onset time have no effect on the heterogeneity. The funnel plots showed the existence of publication bias.Meta-analysis showed IL-8 had a moderate accuracy (AUC=0.8908 for the diagnosis of NS. IL-8 is a helpful biomarker for early diagnosis of NS. However, we should combine the results with clinical symptoms and signs, laboratory and microbial results.

Validity of the alcohol purchase task: a meta-analysis.

Science.gov (United States)

Kiselica, Andrew M; Webber, Troy A; Bornovalova, Marina A

2016-05-01

Behavioral economists assess alcohol consumption as a function of unit price. This method allows construction of demand curves and demand indices, which are thought to provide precise numerical estimates of risk for alcohol problems. One of the more commonly used behavioral economic measures is the Alcohol Purchase Task (APT). Although the APT has shown promise as a measure of risk for alcohol problems, the construct validity and incremental utility of the APT remain unclear. This paper presents a meta-analysis of the APT literature. Sixteen studies were included in the meta-analysis. Studies were gathered via searches of the PsycInfo, PubMed, Web of Science and EconLit research databases. Random-effects meta-analyses with inverse variance weighting were used to calculate summary effect sizes for each demand index-drinking outcome relationship. Moderation of these effects by drinking status (regular versus heavy drinkers) was examined. Additionally, tests of the incremental utility of the APT indices in predicting drinking problems above and beyond measuring alcohol consumption were performed. The APT indices were correlated in the expected directions with drinking outcomes, although many effects were small in size. These effects were typically not moderated by the drinking status of the samples. Additionally, the intensity metric demonstrated incremental utility in predicting alcohol use disorder symptoms beyond measuring drinking. The Alcohol Purchase Task appears to have good construct validity, but limited incremental utility in estimating risk for alcohol problems. © 2015 Society for the Study of Addiction.

Racism and health service utilisation: A systematic review and meta-analysis

Science.gov (United States)

Cormack, Donna; Harris, Ricci; Paradies, Yin

2017-01-01

Although racism has been posited as driver of racial/ethnic inequities in healthcare, the relationship between racism and health service use and experience has yet to be systematically reviewed or meta-analysed. This paper presents a systematic review and meta-analysis of quantitative empirical studies that report associations between self-reported racism and various measures of healthcare service utilisation. Data were reviewed and extracted from 83 papers reporting 70 studies. Studies included 250,850 participants and were conducted predominately in the U.S. The meta-analysis included 59 papers reporting 52 studies, which were analysed using random effects models and mean weighted effect sizes. Racism was associated with more negative patient experiences of health services (HSU-E) (OR = 0.351 (95% CI [0.236,0.521], k = 19), including lower levels of healthcare-related trust, satisfaction, and communication. Racism was not associated with health service use (HSU-U) as an outcome group, and was not associated with most individual HSU-U outcomes, including having had examinations, health service visits and admissions to health professionals and services. Racism was associated with health service use outcomes such as delaying/not getting healthcare, and lack of adherence to treatment uptake, although these effects may be influenced by a small sample of studies, and publication bias, respectively. Limitations to the literature reviewed in terms of study designs, sampling methods and measurements are discussed along with suggested future directions in the field. PMID:29253855

Racism and health service utilisation: A systematic review and meta-analysis.

Science.gov (United States)

Ben, Jehonathan; Cormack, Donna; Harris, Ricci; Paradies, Yin

2017-01-01

Although racism has been posited as driver of racial/ethnic inequities in healthcare, the relationship between racism and health service use and experience has yet to be systematically reviewed or meta-analysed. This paper presents a systematic review and meta-analysis of quantitative empirical studies that report associations between self-reported racism and various measures of healthcare service utilisation. Data were reviewed and extracted from 83 papers reporting 70 studies. Studies included 250,850 participants and were conducted predominately in the U.S. The meta-analysis included 59 papers reporting 52 studies, which were analysed using random effects models and mean weighted effect sizes. Racism was associated with more negative patient experiences of health services (HSU-E) (OR = 0.351 (95% CI [0.236,0.521], k = 19), including lower levels of healthcare-related trust, satisfaction, and communication. Racism was not associated with health service use (HSU-U) as an outcome group, and was not associated with most individual HSU-U outcomes, including having had examinations, health service visits and admissions to health professionals and services. Racism was associated with health service use outcomes such as delaying/not getting healthcare, and lack of adherence to treatment uptake, although these effects may be influenced by a small sample of studies, and publication bias, respectively. Limitations to the literature reviewed in terms of study designs, sampling methods and measurements are discussed along with suggested future directions in the field.

Bayesian meta-analysis models for microarray data: a comparative study

Directory of Open Access Journals (Sweden)

Song Joon J

2007-03-01

Full Text Available Abstract Background With the growing abundance of microarray data, statistical methods are increasingly needed to integrate results across studies. Two common approaches for meta-analysis of microarrays include either combining gene expression measures across studies or combining summaries such as p-values, probabilities or ranks. Here, we compare two Bayesian meta-analysis models that are analogous to these methods. Results Two Bayesian meta-analysis models for microarray data have recently been introduced. The first model combines standardized gene expression measures across studies into an overall mean, accounting for inter-study variability, while the second combines probabilities of differential expression without combining expression values. Both models produce the gene-specific posterior probability of differential expression, which is the basis for inference. Since the standardized expression integration model includes inter-study variability, it may improve accuracy of results versus the probability integration model. However, due to the small number of studies typical in microarray meta-analyses, the variability between studies is challenging to estimate. The probability integration model eliminates the need to model variability between studies, and thus its implementation is more straightforward. We found in simulations of two and five studies that combining probabilities outperformed combining standardized gene expression measures for three comparison values: the percent of true discovered genes in meta-analysis versus individual studies; the percent of true genes omitted in meta-analysis versus separate studies, and the number of true discovered genes for fixed levels of Bayesian false discovery. We identified similar results when pooling two independent studies of Bacillus subtilis. We assumed that each study was produced from the same microarray platform with only two conditions: a treatment and control, and that the data sets

Blood Warming and Hemolysis: A Systematic Review With Meta-Analysis.

Science.gov (United States)

Poder, Thomas G; Nonkani, Wendyam G; Tsakeu Leponkouo, Élyonore

2015-07-01

The use of fluid warmers during blood transfusion is recommended to avoid inducing hypothermia and its harmful effects. Fluid warmers offered by manufacturers can reach temperatures of 43°C. However, the recommendations of national regulatory organizations do not clearly indicate the maximum heating temperature in relation to the risk of hemolysis. To fill this gap, we conducted a systematic review of the literature with meta-analysis. To match clinical practice, this review was limited to fluid warmers that used contact heating; thus, studies that used radiofrequency or microwave heating were excluded. Twenty-four observational studies were included, 17 of which were the subject of a meta-analysis. A preliminary descriptive analysis indicated that multiple factors can influence the level of hemolysis during blood heating with a liquid warmer, including blood age, anticoagulant type, duration of exposure to heat, stirring the blood during heating, and various elements of the circuit through which blood flows (eg, type of infusion pump with pressure and flow, type of microfilter, and type of tubing). Moreover, the duration between sampling and hemolysis assay was a source of heterogeneity among studies, as were the initial free hemoglobin levels in the various experiments. In general, the increase generated by each of these factors other than temperature appears to have been limited except for blood age, which is an important parameter of hemolysis, the length of exposure to heat, and, in some studies, the type of infusion pump used. Regarding the meta-analysis, at temperatures at or less than 43°C and even up to 45-46°C, it appears that blood heating is safe and causes hemolysis only in clinically negligible proportions. Copyright © 2015 Elsevier Inc. All rights reserved.

The correlation analysis of tumor necrosis factor-alpha-308G/A polymorphism and venous thromboembolism risk: A meta-analysis.

Science.gov (United States)

Gao, Quangen; Zhang, Peijin; Wang, Wei; Ma, He; Tong, Yue; Zhang, Jing; Lu, Zhaojun

2016-10-01

Venous thromboembolism is a common complex disorder, being the resultant of gene-gene and gene-environment interactions. Tumor necrosis factor-alpha is a proinflammatory cytokine which has been implicated in venous thromboembolism risk. A promoter 308G/A polymorphism in the tumor necrosis factor-alpha gene has been suggested to modulate the risk for venous thromboembolism. However, the published findings remain inconsistent. In this study, we conducted a meta-analysis of all available data regarding this issue. Eligible studies were identified through search of Pubmed, EBSCO Medline, Web of Science, and China National Knowledge Infrastructure (CNKI, Chinese) databases up to June 2014. Pooled Odd ratios (ORs) with 95% confidence intervals were applied to estimating the strength of the genetic association in the random-effects model or fixed-effects model. A total of 10 studies involving 1999 venous thromboembolism cases and 2166 controls were included in this meta-analysis to evaluate the association between tumor necrosis factor-alpha-308G/A polymorphism and venous thromboembolism risk. Overall, no significantly increased risk venous thromboembolism was observed in all comparison models when all studies were pooled into the meta-analysis. However, in stratified analyses by ethnicity, there was a pronounced association with venous thromboembolism risk among West Asians in three genetic models (A vs. G: OR = 1.82, 95%CI = 1.13-2.94; GA vs. GG: OR = 1.82, 95%CI = 1.08-3.06; AA/GA vs. GG: OR = 1.88, 95%CI = 1.12-3.16). When stratifying by source of controls, no significant result was detected in all genetic models. This meta-analysis demonstrates that tumor necrosis factor-alpha 308G/A polymorphism may contribute to susceptibility to venous thromboembolism among West Asians. Studies are needed to ascertain these findings in larger samples and different racial groups. © The Author(s) 2015.

Interleukin 1 beta gene and risk of schizophrenia: detailed case-control and family-based studies and an updated meta-analysis.

Science.gov (United States)

Shibuya, Masako; Watanabe, Yuichiro; Nunokawa, Ayako; Egawa, Jun; Kaneko, Naoshi; Igeta, Hirofumi; Someya, Toshiyuki

2014-01-01

Interleukin-1 beta (IL-1β) has been implicated in the pathophysiology of schizophrenia. To assess whether the IL1B gene confers increased susceptibility to schizophrenia, we conducted case-control and family-based studies and an updated meta-analysis. We tested the association between IL1B and schizophrenia in 1229 case-control and 112 trio samples using 12 markers, including common tagging single nucleotide variations (SNVs) and a rare non-synonymous variation detected by resequencing the coding regions. We also performed a meta-analysis of rs16944 using a total of 8724 case-control and 201 trio samples from 16 independent populations. We found no significant associations between any of the 12 SNVs examined and schizophrenia in either case-control or trio samples. Moreover, our meta-analysis results showed no significant association between the common SNV, rs16944, and schizophrenia. The present study does not support a role for IL1B in schizophrenia susceptibility.

Statin treatment and functional outcome after ischemic stroke: case-control and meta-analysis.

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Biffi, Alessandro; Devan, William J; Anderson, Christopher D; Cortellini, Lynelle; Furie, Karen L; Rosand, Jonathan; Rost, Natalia S

2011-05-01

Multiple studies suggest that statin use before acute ischemic stroke is associated with improved functional outcome. However, available evidence is conflicting, and several published reports are limited by small sample sizes. We therefore investigated the effect of antecedent use of statins on stroke outcome by performing a meta-analysis of all results from published studies as well as our own unpublished data. We performed a systematic literature search and meta-analysis of studies investigating the association between prestroke statin use and clinical outcome and included additional data from 126 prestroke statin users and 767 nonusers enrolled at our institution. A total of 12 studies, comprising 2013 statin users and 9682 nonusers, was meta-analyzed using a random effects model. We also meta-analyzed results for individual Trial of ORG 10172 in Acute Stroke Treatment stroke subtypes to determine whether the effect of statin use differed across subtypes using the Breslow-Day test. Meta-analysis of all available data identified an association between prestroke statin use and improved functional outcome (OR, 1.62; 95% CI, 1.39 to 1.88), but we uncovered evidence of publication bias. The effect of statin use on functional outcome was found to be larger for small vessel strokes compared with other subtypes (Breslow-Day P=0.008). Antecedent use of statins is associated with improved outcome in patients with acute ischemic stroke. This association appears to be stronger in patients with small vessel stroke subtype. However, evidence of publication bias in the existing literature suggests these findings should be interpreted with caution.

Wind power externalities: A meta-analysis

NARCIS (Netherlands)

Mattmann, M.; Logar, I.; Brouwer, R.

2016-01-01

This study presents the first quantitative meta-analysis of the non-market valuation literature on the external effects associated with wind power production. A data set of 60 observations drawn from 32 studies is constructed. The relative economic values of different types of externalities as well

A Systematic Review and Meta-Analysis of Baseline Ohip-Edent Scores.

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Duale, J M J; Patel, Y A; Wu, J; Hyde, T P

2018-03-01

OHIP-EDENT is widely used in the literature to assess Oral-Health-Related-Quality-of-Life (OHRQoL) for edentulous patients. However the normal variance and mean of the baseline OHIP scores has not been reported. It would facilitate critical appraisal of studies if we had knowledge of the normal variation and mean of baseline OHIP-EDENT scores. An established figure for baseline OHIP-EDENT, obtained from a meta-analysis, would simplify comparisons of studies and quantify variations in initial OHRQoL of the trial participants. The aim of this study is to quantify a normal baseline value for pre-operative OHIP-EDENT scores by a systematic review and meta-analysis of the available literature. A systematic literature review was carried. 83 papers were identified that included OHIP-EDENT values. After screening and eligibility assessment, 7 papers were selected and included in the meta-analysis. A meta-analysis for the 7 papers by a random-effect model yielded a mean baseline OHIP-EDENT score of 28.63 with a 95% Confidence intervals from 21.93 to 35.34. A pre-operative baseline OHIP-EDENT has been established by meta-analysis of published papers. This will facilitate the comparison of the initial OHRQoL of one study population to that found elsewhere in the published literature. Copyright© 2018 Dennis Barber Ltd.

Discrimination against Latina/os: A Meta-Analysis of Individual-Level Resources and Outcomes

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Lee, Debbiesiu L.; Ahn, Soyeon

2012-01-01

This meta-analysis synthesizes the findings of 60 independent samples from 51 studies examining racial/ethnic discrimination against Latina/os in the United States. The purpose was to identify individual-level resources and outcomes that most strongly relate to discrimination. Discrimination against Latina/os significantly results in outcomes…

The Effect of Educational Leadership on Students' Achievement: A Meta-Analysis Study

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Karadag, Engin; Bektas, Fatih; Çogaltay, Nazim; Yalçin, Mikail

2015-01-01

In this meta-analysis study, different leadership styles were combined, and the relationship between educational leadership and student achievement was analyzed. In the literature review, 57 research articles/dissertations, independent from one another, were brought together, and 28,964 study subjects were included in the sample group. The results…

LBLOCA sensitivity analysis using meta models

International Nuclear Information System (INIS)

Villamizar, M.; Sanchez-Saez, F.; Villanueva, J.F.; Carlos, S.; Sanchez, A.I.; Martorell, S.

2014-01-01

This paper presents an approach to perform the sensitivity analysis of the results of simulation of thermal hydraulic codes within a BEPU approach. Sensitivity analysis is based on the computation of Sobol' indices that makes use of a meta model, It presents also an application to a Large-Break Loss of Coolant Accident, LBLOCA, in the cold leg of a pressurized water reactor, PWR, addressing the results of the BEMUSE program and using the thermal-hydraulic code TRACE. (authors)

MR diffusion weighted imaging detecting cerebral infarction: a meta-analysis

International Nuclear Information System (INIS)

Yang Junle; Xu Min; Wang Peng; Zhang Qiujuan; Guo Youmin; Liu Min

2008-01-01

Objective: To determine the diagnostic value of diffusion-weighted imaging(DWI) in hyperacute and acute cerebral infarction by using Meta-analysis. Methods: Based on validity criteria for diagnostic research published by the Cochrane Methods Group on Screening and Diagnostic, studies in English and Chinese from 1997 to 2007 were selected from Medline, Cochrane, Springer, Ovid, Elsevier, LWW and CNKI( China National Knowledge Infrastructure). The characteristics of the included articles were appraised and extracted. Statistical analysis was performed with the software Meta-test 0.6 and Comprehensive meta-analysis 2.0. Heterogeneity of the included articles was tested, which was used to select proper effect model to calculate pooled weighted values of sensitivity and specificity and the corresponding 95% CI. Summary receiver operating characteristic (SROC) curve was performed and the area under the curve (Az) was calculated. Publication bias was analyzed by Funnel Plot in Comprehensive Meta- analysis 2.0. A sensitivity analysis was performed. Results: Twelve articles meeting inclusion criteria were analyzed for the value of DWI in hyperacute cerebral infarction. The pooled sensitivity, specificity and diagnostic odds ratio was 92%, 87%, 180.37 respectively, Az=0.9717. Novice is a main factor for total diagnostic effect (Q=4.34, P>0.05). Non-asymmetric funnel plot suggested the publication bias. Fifteen articles meeting inclusion criteria were analyzed for the value of DWI in both hyperacute and acute cerebral infarction (≤ 24 h). The pooled sensitivity, specificity diagnostic odds ratio was 92%, 91%, 623.62 respectively, Az=0.9659. Fixed effects model used in Meta-analysis for database suggested homogeneity (Q=2.70,P>0.05). Nonasymmetric funnel plot suggested the publication bias. Conclusions As a noninvasive method, diffusion-weighted imaging is valuable in detecting hyperacute and acute cerebral infarction. More support from multi-center prospective researches is

Lifetime Prevalence of Suicide Attempts Among Sexual Minority Adults by Study Sampling Strategies: A Systematic Review and Meta-Analysis.

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Hottes, Travis Salway; Bogaert, Laura; Rhodes, Anne E; Brennan, David J; Gesink, Dionne

2016-05-01

Previous reviews have demonstrated a higher risk of suicide attempts for lesbian, gay, and bisexual (LGB) persons (sexual minorities), compared with heterosexual groups, but these were restricted to general population studies, thereby excluding individuals sampled through LGB community venues. Each sampling strategy, however, has particular methodological strengths and limitations. For instance, general population probability studies have defined sampling frames but are prone to information bias associated with underreporting of LGB identities. By contrast, LGB community surveys may support disclosure of sexuality but overrepresent individuals with strong LGB community attachment. To reassess the burden of suicide-related behavior among LGB adults, directly comparing estimates derived from population- versus LGB community-based samples. In 2014, we searched MEDLINE, EMBASE, PsycInfo, CINAHL, and Scopus databases for articles addressing suicide-related behavior (ideation, attempts) among sexual minorities. We selected quantitative studies of sexual minority adults conducted in nonclinical settings in the United States, Canada, Europe, Australia, and New Zealand. Random effects meta-analysis and meta-regression assessed for a difference in prevalence of suicide-related behavior by sample type, adjusted for study or sample-level variables, including context (year, country), methods (medium, response rate), and subgroup characteristics (age, gender, sexual minority construct). We examined residual heterogeneity by using τ(2). We pooled 30 cross-sectional studies, including 21,201 sexual minority adults, generating the following lifetime prevalence estimates of suicide attempts: 4% (95% confidence interval [CI] = 3%, 5%) for heterosexual respondents to population surveys, 11% (95% CI = 8%, 15%) for LGB respondents to population surveys, and 20% (95% CI = 18%, 22%) for LGB respondents to community surveys (Figure 1). The difference in LGB estimates by sample

Religion, Spirituality, and Physical Health in Cancer Patients: A Meta-Analysis

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Jim, Heather S.L.; Pustejovsky, James; Park, Crystal L.; Danhauer, Suzanne C.; Sherman, Allen C.; Fitchett, George; Merluzzi, Thomas V.; Munoz, Alexis R.; George, Login; Snyder, Mallory A.; Salsman, John M.

2015-01-01

Background Whereas religion/spirituality (R/S) is important in its own right for many cancer patients, a large body of research has examined whether R/S is also associated with better physical health outcomes. This literature has been characterized by heterogeneity in sample composition, measures of R/S, and measures of physical health. In an effort to synthesize previous findings, we conducted a meta-analysis of the relationship between R/S and patient-reported physical health in cancer patients. Methods A search of PubMed, PsycInfo, CINAHL, and Cochrane Library yielded 2,073 abstracts, which were independently evaluated by pairs of raters. Meta-analysis was conducted on 497 effect sizes from 101 unique samples encompassing over 32,000 adult cancer patients. R/S measures were categorized into affective, behavioral, cognitive, and ‘other’ dimensions. Physical health measures were categorized into physical well-being, functional well-being, and physical symptoms. Average estimated correlations (Fisher's z) were calculated using generalized estimating equations with robust variance estimation. Results Overall R/S was associated with overall physical health (z=.153, p<.001); this relationship was not moderated by sociodemographic or clinical variables. Affective R/S was associated with physical well-being (z=.167, p<.001), functional well-being (z=.343, p<.001), and physical symptoms (z=.282, p<.001). Cognitive R/S was associated with physical well-being (z=.079, p<.05) and functional well-being (z=.090, p<.01). ‘Other’ R/S was associated with functional well-being (z=.100, p<.05). Conclusions Results of the current meta-analysis suggest that greater R/S is associated with better patient-reported physical health. These results underscore the importance of attending to patients’ religious and spiritual needs as part of comprehensive cancer care. PMID:26258868

Spatial Bayesian latent factor regression modeling of coordinate-based meta-analysis data.

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Montagna, Silvia; Wager, Tor; Barrett, Lisa Feldman; Johnson, Timothy D; Nichols, Thomas E

2018-03-01

Now over 20 years old, functional MRI (fMRI) has a large and growing literature that is best synthesised with meta-analytic tools. As most authors do not share image data, only the peak activation coordinates (foci) reported in the article are available for Coordinate-Based Meta-Analysis (CBMA). Neuroimaging meta-analysis is used to (i) identify areas of consistent activation; and (ii) build a predictive model of task type or cognitive process for new studies (reverse inference). To simultaneously address these aims, we propose a Bayesian point process hierarchical model for CBMA. We model the foci from each study as a doubly stochastic Poisson process, where the study-specific log intensity function is characterized as a linear combination of a high-dimensional basis set. A sparse representation of the intensities is guaranteed through latent factor modeling of the basis coefficients. Within our framework, it is also possible to account for the effect of study-level covariates (meta-regression), significantly expanding the capabilities of the current neuroimaging meta-analysis methods available. We apply our methodology to synthetic data and neuroimaging meta-analysis datasets. © 2017, The International Biometric Society.

Spatial Bayesian Latent Factor Regression Modeling of Coordinate-based Meta-analysis Data

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Montagna, Silvia; Wager, Tor; Barrett, Lisa Feldman; Johnson, Timothy D.; Nichols, Thomas E.

2017-01-01

Summary Now over 20 years old, functional MRI (fMRI) has a large and growing literature that is best synthesised with meta-analytic tools. As most authors do not share image data, only the peak activation coordinates (foci) reported in the paper are available for Coordinate-Based Meta-Analysis (CBMA). Neuroimaging meta-analysis is used to 1) identify areas of consistent activation; and 2) build a predictive model of task type or cognitive process for new studies (reverse inference). To simultaneously address these aims, we propose a Bayesian point process hierarchical model for CBMA. We model the foci from each study as a doubly stochastic Poisson process, where the study-specific log intensity function is characterised as a linear combination of a high-dimensional basis set. A sparse representation of the intensities is guaranteed through latent factor modeling of the basis coefficients. Within our framework, it is also possible to account for the effect of study-level covariates (meta-regression), significantly expanding the capabilities of the current neuroimaging meta-analysis methods available. We apply our methodology to synthetic data and neuroimaging meta-analysis datasets. PMID:28498564

Dietary patterns and colorectal cancer risk: a meta-analysis.

Science.gov (United States)

Feng, Yu-Liang; Shu, Long; Zheng, Pei-Fen; Zhang, Xiao-Yan; Si, Cai-Juan; Yu, Xiao-Long; Gao, Wei; Zhang, Lun

2017-05-01

The analysis of dietary patterns has recently drawn considerable attention as a method of investigating the association between the overall whole diet and the risk of colorectal cancer. However, the results have yielded conflicting findings. Here, we carried out a meta-analysis to identify the association between dietary patterns and the risk of colorectal cancer. A total of 40 studies fulfilled the inclusion criteria and were included in this meta-analysis. The highest category of 'healthy' dietary pattern compared with the lowest category was apparently associated with a decreased risk for colorectal cancer [odds ratio (OR)=0.75; confidence interval (CI): 0.68-0.83; Pcolorectal cancer was shown for the highest compared with the lowest category of a 'western-style' dietary pattern (OR=1.40; CI: 1.26-1.56; Pcolorectal cancer in the highest compared with the lowest category of 'alcohol-consumption' pattern (OR=1.44; CI: 1.13-1.82; P=0.003). The results of this meta-analysis indicate that a 'healthy' dietary pattern may decrease the risk of colorectal cancer, whereas 'western-style' and 'alcohol-consumption' patterns may increase the risk of colorectal cancer.

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

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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.

Meta-Analysis of the Antidepressant Effects of Acute Sleep Deprivation.

Science.gov (United States)

Boland, Elaine M; Rao, Hengyi; Dinges, David F; Smith, Rachel V; Goel, Namni; Detre, John A; Basner, Mathias; Sheline, Yvette I; Thase, Michael E; Gehrman, Philip R

To provide a quantitative meta-analysis of the antidepressant effects of sleep deprivation to complement qualitative reviews addressing response rates. English-language studies from 1974 to 2016 using the keywords sleep deprivation and depression searched through PubMed and PsycINFO databases. A total of 66 independent studies met criteria for inclusion: conducted experimental sleep deprivation, reported the percentage of the sample that responded to sleep deprivation, provided a priori definition of antidepressant response, and did not seamlessly combine sleep deprivation with other therapies (eg, chronotherapeutics, repetitive transcranial magnetic stimulation). Data extracted included percentage of responders, type of sample (eg, bipolar, unipolar), type of sleep deprivation (eg, total, partial), demographics, medication use, type of outcome measure used, and definition of response (eg, 30% reduction in depression ratings). Data were analyzed with meta-analysis of proportions and a Poisson mixed-effects regression model. The overall response rate to sleep deprivation was 45% among studies that utilized a randomized control group and 50% among studies that did not. The response to sleep deprivation was not affected significantly by the type of sleep deprivation performed, the nature of the clinical sample, medication status, the definition of response used, or age and gender of the sample. These findings support a significant effect of sleep deprivation and suggest the need for future studies on the phenotypic nature of the antidepressant response to sleep deprivation, on the neurobiological mechanisms of action, and on moderators of the sleep deprivation treatment response in depression. © Copyright 2017 Physicians Postgraduate Press, Inc.

Prevalence of Congenital Anomalies in Iran: A Systematic Review and Meta-analysis

Directory of Open Access Journals (Sweden)

Salman Daliri

2018-05-01

Full Text Available Background: Congenital anomaly is a disturbance in fetal growth and development during pregnancy and is one of the main causes of morbidity and mortality in the first year of life. In addition, this anomaly causes a large waste of heath care resources. We aimed to determine the prevalence and proportion rates of different congenital anomalies in Iran via a systematic review and meta-analysis.Methods: The present study was performed to estimate the prevalence and proportion rates of different anomalies in Iran via a systematic review and meta-analysis. Therefore, all the studies performed in Iran between 2000 and 2016 were evaluated. For this purpose, Medlib, Scopus, Web of Science, PubMed, Cochrane Library, Science Direct, Google Scholar, Irandoc, Magiran, IranMedex, and SID databases were searched by two different expert individuals independently. For the qualification survey of the papers, the Strengthening the Reporting of Observational Studies in Epidemiology checklist was applied. Then, the extracted data were entered into STATA (ver.11.1 and analysed using statistical tests of stability and random effects models in meta-regression, a tool used in meta-analysis. The 95% confidence intervals were calculated by I-square models. Meta regression was introduced to explore the heterogeneities among studies.Results: Overall, 36 papers with a total sample size of 909,961 neonates were analysed. The total prevalence rate for congenital anomalies was 18/1000 live births, 23.2/1000 and 18/1000 for boys and girls, respectively. Moreover, 55.8% of all congenital anomalies pertained to boys. The greatest prevalence and proportion rates of congenital anomalies belonged to musculoskeletal disorders followed by urogenital anomalies (9.3/1000 [34%] and 5.7/1000 [20%], respectively, and the lowest figures belonged to chromosomal and respiratory system anomalies (0.8/1000 [6%] and 0.3/1000 [2%], respectively.Conclusion: According to the findings of this meta-analysis

Sex differences in visual-spatial working memory: A meta-analysis.

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Voyer, Daniel; Voyer, Susan D; Saint-Aubin, Jean

2017-04-01

Visual-spatial working memory measures are widely used in clinical and experimental settings. Furthermore, it has been argued that the male advantage in spatial abilities can be explained by a sex difference in visual-spatial working memory. Therefore, sex differences in visual-spatial working memory have important implication for research, theory, and practice, but they have yet to be quantified. The present meta-analysis quantified the magnitude of sex differences in visual-spatial working memory and examined variables that might moderate them. The analysis used a set of 180 effect sizes from healthy males and females drawn from 98 samples ranging in mean age from 3 to 86 years. Multilevel meta-analysis was used on the overall data set to account for non-independent effect sizes. The data also were analyzed in separate task subgroups by means of multilevel and mixed-effects models. Results showed a small but significant male advantage (mean d = 0.155, 95 % confidence interval = 0.087-0.223). All the tasks produced a male advantage, except for memory for location, where a female advantage emerged. Age of the participants was a significant moderator, indicating that sex differences in visual-spatial working memory appeared first in the 13-17 years age group. Removing memory for location tasks from the sample affected the pattern of significant moderators. The present results indicate a male advantage in visual-spatial working memory, although age and specific task modulate the magnitude and direction of the effects. Implications for clinical applications, cognitive model building, and experimental research are discussed.

Methadone Poisoning in Children: A Systematic Review and Meta-Analysis in Iran

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Yasaman Allameh

2017-05-01

Full Text Available Context Symptoms of methadone poisoning, as one of the most dangerous types of poisoning, are very serious in children. Objectives The aim of this study was to describe causes and clinical symptoms of methadone poisoning in children admitted to hospitals in Iran. Data Sources Relevant studies published in national and international journals before January 29, 2016 were identified by studying the available databases, including PubMed, Web of Sciences, Google Scholar, Scopus, SID, Iranmedex, MagIran, and Irandoc. Study Selection After excluding duplicate, irrelevant, and low-quality articles, relevant papers were entered into the meta-analysis. The prevalence, mean, and standard deviation of methadone poisoning symptoms in children were statistically analyzed, using Stata version 11, and causes of methadone poisoning were presented in tables. Data Extraction Studies with unknown sample sizes, abstracts without access to full text, articles with quality assessment scores below 15.5, and studies carried out on non-Iranian populations were excluded from the meta-analysis. Results During the initial advanced search, 1594 articles were identified. After quality assessment, 12 papers were found eligible for the final systematic review and meta-analysis, based on the inclusion and exclusion criteria. The reported symptoms included drowsiness, vomiting, apnea, cyanosis, seizure, ataxia, and delirium. In the meta-analysis, prevalence of symptoms in referred patients was estimated at 44% (0.95% confidence interval, 0.288 to 0.609. The causes of poisoning in children included accidental feeding by parents, storage of drugs in inappropriate containers, parental addiction, and low educational level of parents. Conclusions It is important to keep methadone in a suitable container away from children. Also, it is essential to focus on educating parents on health issues of their children.

Global meta-analysis of transcriptomics studies.

Directory of Open Access Journals (Sweden)

José Caldas

Full Text Available Transcriptomics meta-analysis aims at re-using existing data to derive novel biological hypotheses, and is motivated by the public availability of a large number of independent studies. Current methods are based on breaking down studies into multiple comparisons between phenotypes (e.g. disease vs. healthy, based on the studies' experimental designs, followed by computing the overlap between the resulting differential expression signatures. While useful, in this methodology each study yields multiple independent phenotype comparisons, and connections are established not between studies, but rather between subsets of the studies corresponding to phenotype comparisons. We propose a rank-based statistical meta-analysis framework that establishes global connections between transcriptomics studies without breaking down studies into sets of phenotype comparisons. By using a rank product method, our framework extracts global features from each study, corresponding to genes that are consistently among the most expressed or differentially expressed genes in that study. Those features are then statistically modelled via a term-frequency inverse-document frequency (TF-IDF model, which is then used for connecting studies. Our framework is fast and parameter-free; when applied to large collections of Homo sapiens and Streptococcus pneumoniae transcriptomics studies, it performs better than similarity-based approaches in retrieving related studies, using a Medical Subject Headings gold standard. Finally, we highlight via case studies how the framework can be used to derive novel biological hypotheses regarding related studies and the genes that drive those connections. Our proposed statistical framework shows that it is possible to perform a meta-analysis of transcriptomics studies with arbitrary experimental designs by deriving global expression features rather than decomposing studies into multiple phenotype comparisons.

Molecular genetic studies in Saudi population; identified variants from GWAS and meta-analysis in stroke.

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Alharbi, Khalid Khalaf; Ali Khan, Imran; Alotaibi, Mohammad Abdullah; Saud Aloyaid, Abdullah; Al-Basheer, Haifa Abdulaziz; Alghamdi, Naelah Abdullah; Al-Baradie, Raid Saleem; Al-Sulaiman, A M

2018-01-01

Stroke is a multifactorial and heterogeneous disorder, correlates with heritability and considered as one of the major diseases. The prior reports performed the variable models such as genome-wide association studies (GWAS), replication, case-control, cross-sectional and meta-analysis studies and still, we lack diagnostic marker in the global world. There are limited studies were carried out in Saudi population, and we aim to investigate the molecular association of single nucleotide polymorphisms (SNPs) identified through GWAS and meta-analysis studies in stroke patients in the Saudi population. In this case-control study, we have opted gender equality of 207 cases and 207 controls from the capital city of Saudi Arabia in King Saud University Hospital. The peripheral blood (5 ml) sample will be collected in two different vacutainers, and three mL of the coagulated blood will be used for lipid analysis (biochemical tests) and two mL will be used for DNA analysis (molecular tests). Genomic DNA will be extracted with the collected blood samples, and specific primers will be designed for the opted SNPs ( SORT1 -rs646218 and OLR1 -rs11053646 polymorphisms) and PCR-RFLP will be performed and randomly DNA sequencing will be carried out to cross check the results. The rs646218 and rs11053646 polymorphisms were significantly associated with allele, genotype and dominant models with and without crude odds ratios (OR's) and Multiple logistic regression analysis (p Saudi population. The current results were in the association with the prior study results documented through GWAS and meta-analysis association. However, other ethnic population studies should be performed to rule out in the human hereditary diseases.

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

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

2017-04-01

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, EMBASE and Cumulative Index to Nursing and Allied Health Literature (CINAHL) to May 2015. We included studies that reported recalled birth weight and recorded birth weight. We excluded studies investigating a clinical population. Two reviewers independently reviewed citations, extracted data, assessed risk of bias. Data were pooled in a random effects meta-analysis for correlation and mean difference. In total, 40 studies were eligible for qualitative synthesis (n=78,997 births from 78,196 parents). Agreement between recalled and recorded birth weight was high: pooled estimate of correlation in 23 samples from 19 studies (n=7406) was 0.90 [95% confidence interval (CI) 0.87-0.93]. The difference between recalled and recorded birth weight in 29 samples from 26 studies (n=29,293) was small [range -86-129 g; random effects estimate 1.4 g (95% CI -4.0-6.9 g)]. Studies were heterogeneous, with no evidence for an effect of time since birth, person reporting, recall bias, or birth order. In post-hoc subgroup analysis, recall was higher than recorded birth weight by 80 g (95% CI 57-103 g) in low and middle income countries. In conclusion, there is high agreement between recalled and recorded birth weight. If birth weight is recalled, it is suitable for use in epidemiological studies, at least in high income countries.

Meta-analysis of the antecedent and consequent constructs of materialism

OpenAIRE

Fernando de Oliveira Santini; Wagner Júnior Ladeira; Cláudio Hoffmann Sampaio; Clécio Falcão Araújo

2017-01-01

Purpose – Materialism has been gaining ground in the academic field, especially from the 1980s on, given the relevance of understanding sentiments connected to possessing and acquiring goods. Thus, this meta-analysis was carried out to assess the antecedents and consequents of materialism. Design/methodology/approach – Based on a systematic review, we gathered a total 77 articles that examined those aspects, generating 99 effects-sizes and a cumulative sample of 40,288 studied individuals...

Swimming attendance during childhood and development of asthma: Meta-analysis.

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Valeriani, Federica; Protano, Carmela; Vitali, Matteo; Romano Spica, Vincenzo

2017-05-01

The association between asthma and swimming pool attendance has not been demonstrated and currently there are conflicting results. In order to clarify the association between asthma diagnosis in children and swimming pool attendance, and to assess the consistency of the available epidemiological studies, we completed a literature analysis on the relationship between the exposure to disinfection by-products in indoor swimming pools during childhood and asthma diagnosis. Following the Meta-analysis of Observational Studies in Epidemiology (MOOSE) and Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) criteria, a systematic review and meta-analysis was performed by searching MEDLINE via PubMed, TOXNET, and Scopus databases (from inception to 20 April 2015) using the key word "Asthma" together with "swimming pool", "disinfection by-products", "indoor air pollution" and "children". Inclusion criteria were: English language, a complete analytic study design involving a cohort of children (0-16 years), a well-defined definition of exposure, and the presence of data on effect and variance. Studies on in vivo, in vitro or professional and accidental exposure were excluded. After a screening process, seven reports (n = 5851 subjects) were included out of a total of 2928 references. The reported OR of the association between swimming pool attendance and asthma prevalence ranged from 0.58 to 2.30. The present meta-analysis failed to identify a significant difference in asthma development between children attending swimming pools and controls (OR, 1.084; 95% CI: 0.89-1.31). Swimming in childhood does not increase the likelihood of doctor-diagnosed asthma. Based on this meta-analysis review, the association of the disease with indoor pool attendance is still unclear. © 2016 Japan Pediatric Society.

The correlation of social support with mental health: A meta-analysis

Science.gov (United States)

Harandi, Tayebeh Fasihi; Taghinasab, Maryam Mohammad; Nayeri, Tayebeh Dehghan

2017-01-01

Background and aim Social support is an important factor that can affect mental health. In recent decades, many studies have been done on the impact of social support on mental health. The purpose of the present study is to investigate the effect size of the relationship between social support and mental health in studies in Iran. Methods This meta-analysis was carried out in studies that were performed from 1996 through 2015. Databases included SID and Magiran, the comprehensive portal of human sciences, Noor specialized magazine databases, IRANDOC, Proquest, PubMed, Scopus, ERIC, Iranmedex and Google Scholar. The keywords used to search these websites included “mental health or general health,” and “Iran” and “social support.” In total, 64 studies had inclusion criteria meta-analysis. In order to collect data used from a meta-analysis worksheet that was made by the researcher and for data analysis software, CMA-2 was used. Results The mean of effect size of the 64 studies in the fixed-effect model and random-effect model was obtained respectively as 0.356 and 0.330, which indicated the moderate effect size of social support on mental health. The studies did not have publication bias, and enjoyed a heterogeneous effect size. The target population and social support questionnaire were moderator variables, but sex, sampling method, and mental health questionnaire were not moderator variables. Conclusion Regarding relatively high effect size of the correlation between social support and mental health, it is necessary to predispose higher social support, especially for women, the elderly, patients, workers, and students. PMID:29038699

Prevalence of gestational diabetes mellitus in Europe: A meta-analysis.

Science.gov (United States)

Eades, Claire E; Cameron, Dawn M; Evans, Josie M M

2017-07-01

Estimates of the prevalence of gestational diabetes vary widely. It is important to have a clear understanding of the prevalence of this condition to be able to plan interventions and health care provision. This paper describes a meta-analysis of primary research data reporting the prevalence of gestational diabetes mellitus in the general pregnant population of developed countries in Europe. Four electronic databases were systematically searched in May 2016. English language articles reporting gestational diabetes mellitus prevalence using universal screening in general pregnant population samples from developed countries in Europe were included. All papers identified by the search were screened by one author, and then half screened independently by a second author and half by a third author. Data were extracted by one author. Values for the measures of interest were combined using a random effects model and analysis of the effects of moderator variables was carried out. A total of 3258 abstracts were screened, with 40 studies included in the review. Overall prevalence of gestational diabetes mellitus was 5.4% (3.8-7.8). Maternal age, year of data collection, country, area of Europe, week of gestation at testing, and diagnostic criteria were found to have a significant univariate effect on GDM prevalence, and area, week of gestation at testing and year of data collection remained statistically significant in multivariate analysis. Quality category was significant in multivariate but not univariate analysis. This meta-analysis shows prevalence of GDM that is at the upper end of previous estimates in Europe. Copyright © 2017 Elsevier B.V. All rights reserved.

A large replication study and meta-analysis in European samples provides further support for association of AHI1 markers with schizophrenia

DEFF Research Database (Denmark)

Ingason, Andrés; Giegling, Ina; Cichon, Sven

2010-01-01

The Abelson helper integration site 1 (AHI1) gene locus on chromosome 6q23 is among a group of candidate loci for schizophrenia susceptibility that were initially identified by linkage followed by linkage disequilibrium mapping, and subsequent replication of the association in an independent sample....... Here, we present results of a replication study of AHI1 locus markers, previously implicated in schizophrenia, in a large European sample (in total 3907 affected and 7429 controls). Furthermore, we perform a meta-analysis of the implicated markers in 4496 affected and 18,920 controls. Both...... as the neighbouring phosphodiesterase 7B (PDE7B)-may be considered candidates for involvement in the genetic aetiology of schizophrenia....

Content analysis of advertisements related to oral health in children: a systematic review and meta-analysis.

Science.gov (United States)

Pournaghi Azar, F; Mamizadeh, M; Nikniaz, Z; Ghojazadeh, M; Hajebrahimi, S; Salehnia, F; Mashhadi Abdolahi, H

2018-03-01

The evidence about the content of TV advertisements broadcast during children's viewing times with an emphasis on the number of food advertisements and the number of cariogenic food advertisements was systematically reviewed and meta-analyzed. A systematic review and meta-analysis. Articles published up until October 2017 in PubMed, Scopus, Embase, Web of Science, Cochrane Library, and Persian databases such as Magiran, IranDoc, and Iranmedex with the keywords that were related to advertising and oral health in children were searched and screened by two reviewers independently, and the outcomes of interest were extracted. Meta-analysis was performed using the Comprehensive Meta-Analysis, version 2.0. A total of 480 titles were retrieved and reduced to 256 eligible studies after deletion of duplicates, and finally, after closer assessment of titles and abstracts, five articles were selected for systematic review and meta-analysis. Of the included studies, three were conducted in the UK, one in India, and one in Greece. About 38.0% (95% confidence interval: 19.6-60.6, P = 0.296) of advertisements were related to food and also about 70.6% (95% confidence interval: 53.7-83.3, P < 0.019) of food advertisements were related to cariogenic foods. Food advertising during children's programs is dominated by food items that are potentially harmful to oral health. Moreover, the advertisements shifted toward food items that appeared healthy but contain a large amount of hidden sugar. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

[Review of meta-analysis research on exercise in South Korea].

Science.gov (United States)

Song, Youngshin; Gang, Moonhee; Kim, Sun Ae; Shin, In Soo

2014-10-01

The purpose of this study was to evaluate the quality of meta-analysis regarding exercise using Assessment of Multiple Systematic Reviews (AMSTAR) as well as to compare effect size according to outcomes. Electronic databases including the Korean Studies Information Service System (KISS), the National Assembly Library and the DBpia, HAKJISA and RISS4U for the dates 1990 to January 2014 were searched for 'meta-analysis' and 'exercise' in the fields of medical, nursing, physical therapy and physical exercise in Korea. AMSTAR was scored for quality assessment of the 33 articles included in the study. Data were analyzed using descriptive statistics, t-test, ANOVA and χ²-test. The mean score for AMSTAR evaluations was 4.18 (SD=1.78) and about 67% were classified at the low-quality level and 30% at the moderate-quality level. The scores of quality were statistically different by field of research, number of participants, number of databases, financial support and approval by IRB. The effect size that presented in individual studies were different by type of exercise in the applied intervention. This critical appraisal of meta-analysis published in various field that focused on exercise indicates that a guideline such as the PRISMA checklist should be strongly recommended for optimum reporting of meta-analysis across research fields.

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.

Glucose-6-phosphate dehydrogenase deficiency and the risk of malaria: A meta-analysis and trial sequential analysis

Science.gov (United States)

Sun, Fengmei; Zhang, Juan; Pu, Yuepu

2017-10-01

This study is designed to perform a meta-analysis and trial sequential analysis (TSA) to investigate whether people with G6PD deficiency suffered less malarial infection. We searched from PubMed, Science Direct, Springer Link, CNKI, and Wan Fang databases for case-control study, cohort study or cross section study until April 2017. TSA was used to determine the state of evidence and calculate the required sample size. Eight case-control studies and five cross-sectional studies (30,683participants) were included in this meta-analysis. Compared with normal control group, we found significant protection from severe malaria (OR 0.644, 95% CI [0.493-0.842]; P=0.001) among people with decreasing G6PD activity. People with variations of G6PD gene at nucleotide 202(G6PD A-) were also found to be associated with resistance on severe malaria pooled (OR 0.851, 95% CI [0.779-0.930]; P =0.0001). Sex-stratified test suggested that protection of severe malaria is conferred to both G6PD A-males and heterozygous females (with a single copy of the variant). In conclusion, our study found a significant protection from severe malaria among G6PD deficient people compared to the

Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis

NARCIS (Netherlands)

Raak-van den Berg, C.L.; Hemerik, A.; Werf, van der W.; Jong, de P.W.; Lenteren, van J.C.

2017-01-01

Data collected en used for a meta analysis on life history data of H. axyridis. And the resulting 20 best models for each life history characteristic. Published in the paper: Life history of the Harlequin ladybird, Harmonia axyridis; a global meta-analysis.

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.

Updated Meta-Analysis of Learner Control within Educational Technology

Science.gov (United States)

Karich, Abbey C.; Burns, Matthew K.; Maki, Kathrin E.

2014-01-01

Giving a student control over their learning has theoretical and intuitive appeal, but its effects are neither powerful nor consistent in the empirical literature base. This meta-analysis updated previous meta-analytic research by Niemiec, Sikorski, and Walberg by studying the overall effectiveness of providing learner control within educational…

A Bayesian Nonparametric Meta-Analysis Model

Science.gov (United States)

Karabatsos, George; Talbott, Elizabeth; Walker, Stephen G.

2015-01-01

In a meta-analysis, it is important to specify a model that adequately describes the effect-size distribution of the underlying population of studies. The conventional normal fixed-effect and normal random-effects models assume a normal effect-size population distribution, conditionally on parameters and covariates. For estimating the mean overall…

Meta-Analysis of Associations Between Interleukin-10 Polymorphisms and Susceptibility to Vasculitis.

Science.gov (United States)

Jung, Jae Hyun; Song, Gwan Gyu; Lee, Young Ho

2015-01-01

This study determined whether interleukin-10 (IL-10) polymorphisms are associated with susceptibility to vasculitis. A meta-analysis was conducted of the associations between the IL-10 -1082 G/A, -819 C/T, and -592 C/A polymorphisms and the haplotype of the IL-10-1082 G/A, -819 C/T, -592 C/A polymorphisms and vasculitis. A total of 21 comparative studies involving 4121 patients and 5504 controls were considered in the meta-analysis. Meta-analysis revealed no association between the IL-10-1082 G allele and vasculitis in all study subjects (OR = 0.927, 95% CI = 0.780-1.102, p = 0.389). However, disease-specific meta-analysis showed an association between Wegener's granulomatosis (WG) and the IL-10-1082 G allele (OR = 0.729, 95% CI = 0.547-0.971, p = 0.031). Meta-analysis revealed an association between vasculitis and the IL-10-819 C allele (OR = 0.804, 95% CI = 0.706-0.916, p = 0.001) in all study subjects and Behcet's disease (BD) (OR = 0.724, 95% CI = 0.679-0.781, p vasculitis in all study subjects (OR = 0.805, 95% CI = 0.619-0.938, p = 0.005) and BD (OR = 0.718, 95% CI = 0.661-0.781, p vasculitis in Europeans (OR = 1.239, 95% CI = 1.105-1.513, p = 0.035). This meta-analysis showed that IL-10 polymorphisms are associated with vasculitis susceptibility, especially in WG and BD.

Induced abortion rate in Iran: a meta-analysis.

Science.gov (United States)

Motaghi, Zahra; Poorolajal, Jalal; Keramat, Afsaneh; Shariati, Mohammad; Yunesian, Masud; Masoumi, Seyyedeh Zahra

2013-10-01

About 44 million induced abortions take place worldwide annually, of which 50% are unsafe. The results of studies investigated the induced abortion rate in Iran are inconsistent. The aim of this meta-analysis was to estimate the incidence rate of induced abortion in Iran. National and international electronic databases, as well as conference databases until July 2012 were searched. Reference lists of articles were screened and the studies' authors were contacted for additional unpublished studies. Cross-sectional studies addressing induced abortion in Iran were included in this meta-analysis. The primary outcome of interest was the induced abortion rate (the number of abortions per 1000 women aged 15-44 years in a year) or the ratio (the number of abortions per 100 live births in a year). The secondary outcome of interest was the prevalence of unintended pregnancies (the number of mistimed, unplanned, or unwanted pregnancies per total pregnancies). Data were analyzed using random effect models. Of 603 retrieved studies, using search strategy, 10 studies involving 102,394 participants were eventually included in the meta-analysis. The induced abortion rate and ratio were estimated as 8.9 per 1000 women aged 15-44 years (95% CI: 5.46, 12.33) and 5.34 per 100 live births (95% CI: 3.61, 7.07), respectively. The prevalence of unintended pregnancy was estimated as 27.94 per 100 pregnant women (95% CI: 23.46, 32.42). The results of this meta-analysis helped a better understanding of the incidence of induced abortion in Iran compared to the other developing countries in Asia. However, additional sources of data on abortion other than medical records and survey studies are needed to estimate the true rate of unsafe abortion in Iran.

Physical activity and body image among men and boys: A meta-analysis.

Science.gov (United States)

Bassett-Gunter, Rebecca; McEwan, Desmond; Kamarhie, Aria

2017-09-01

Three meta-analytic reviews have concluded that physical activity is positively related to body image. Historically, research regarding physical activity and body image has been disproportionately focused on female samples. For example, the most recent meta-analysis (2009) extracted 56 effect sizes for women and only 12 for men. The current paper provides an update to the literature regarding the relationship between physical activity and body image among men and boys across 84 individual effect sizes. The analysis also provides insight regarding moderator variables including participant age, and physical activity type and intensity. Overall, physical activity was positively related to body image among men and boys with various moderator variables warranting further investigation. Pragmatic implications are discussed as well as the limitations within existing research and need for additional research to further understand moderator and mediator variables. Copyright © 2017 Elsevier Ltd. All rights reserved.

Limitations in Using Multiple Imputation to Harmonize Individual Participant Data for Meta-Analysis.

Science.gov (United States)

Siddique, Juned; de Chavez, Peter J; Howe, George; Cruden, Gracelyn; Brown, C Hendricks

2018-02-01

Individual participant data (IPD) meta-analysis is a meta-analysis in which the individual-level data for each study are obtained and used for synthesis. A common challenge in IPD meta-analysis is when variables of interest are measured differently in different studies. The term harmonization has been coined to describe the procedure of placing variables on the same scale in order to permit pooling of data from a large number of studies. Using data from an IPD meta-analysis of 19 adolescent depression trials, we describe a multiple imputation approach for harmonizing 10 depression measures across the 19 trials by treating those depression measures that were not used in a study as missing data. We then apply diagnostics to address the fit of our imputation model. Even after reducing the scale of our application, we were still unable to produce accurate imputations of the missing values. We describe those features of the data that made it difficult to harmonize the depression measures and provide some guidelines for using multiple imputation for harmonization in IPD meta-analysis.

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

Corellation Between Achievement Motivation and Entrepreneurial Leadership Quality: Meta Analysis

Directory of Open Access Journals (Sweden)

Arman Hakim Nasution

2010-11-01

Full Text Available This article presents a meta analysis of the experimental and survey literature that has examined the effect of achievement motivation, as a part of the big five personality factors, and entrepreneurial leadership quality. This quantitative study review 20 studies based on independent samples (N = 6209. Summary analysis is provided to support the hypothesis in which the achievement motivation has a correlation with entrepreneurial leadership quality on a fairness procedural. Result indicates that the achievement motivation influences the quality of entrepreneurial leadership in a significant value (rc = 0.26. This finding is relevant to all stakeholders (educators, governments, and parents to make a better decision on the development of entrepreneurial leadership policies.

Prevalence of peptic ulcer in Iran: Systematic review and meta-analysis methods.

Science.gov (United States)

Sayehmiri, Kourosh; Abangah, Ghobad; Kalvandi, Gholamreza; Tavan, Hamed; Aazami, Sanaz

2018-01-01

Peptic ulcer is a prevalent problem and symptoms include epigastria pain and heartburn. This study aimed at investigating the prevalence and causes of peptic ulcers in Iran using systematic review and meta-analysis. Eleven Iranian papers published from 2002 to 2016 are selected using valid keywords in the SID, Goggle scholar, PubMed and Elsevier databases. Results of studies pooled using random effects model in meta-analysis. The heterogeneity of the sample was checked using Q test and I 2 index. Total sample size in this study consist of 1335 individuals with peptic ulcer (121 samples per article). The prevalence of peptic ulcers was estimated 34% (95% CI= 0.25 - 0.43). The prevalence of peptic ulcers was 30% and 60% in woman and man respectively. The highest environmental factor (cigarette) has been addressed in 30% (95% CI= 0.23-0.37) of patients. The prevalence of Helicobacter pylori was estimated in 62% (95% CI= 0.49-0.75) of patients. The results of this study show that prevalence of peptic ulcers in Iran (34%) is higher that worldwide rate (6% to 15%). There was an increasing trend in the prevalence of peptic ulcer over a decade from 2002 to 2016.

Bullying and Suicidal Ideation and Behaviors: A Meta-Analysis

Science.gov (United States)

Holt, Melissa K.; Vivolo-Kantor, Alana M.; Polanin, Joshua R.; Holland, Kristin M.; DeGue, Sarah; Matjasko, Jennifer L.; Wolfe, Misty; Reid, Gerald

2015-01-01

BACKGROUND AND OBJECTIVES Over the last decade there has been increased attention to the association between bullying involvement (as a victim, perpetrator, or bully-victim) and suicidal ideation/behaviors. We conducted a meta-analysis to estimate the association between bullying involvement and suicidal ideation and behaviors. METHODS We searched multiple online databases and reviewed reference sections of articles derived from searches to identify cross-sectional studies published through July 2013. Using search terms associated with bullying, suicide, and youth, 47 studies (38.3% from the United States, 61.7% in non-US samples) met inclusion criteria. Seven observers independently coded studies and met in pairs to reach consensus. RESULTS Six different meta-analyses were conducted by using 3 predictors (bullying victimization, bullying perpetration, and bully/victim status) and 2 outcomes (suicidal ideation and suicidal behaviors). A total of 280 effect sizes were extracted and multilevel, random effects meta-analyses were performed. Results indicated that each of the predictors were associated with risk for suicidal ideation and behavior (range, 2.12 [95% confidence interval (CI), 1.67–2.69] to 4.02 [95% CI, 2.39–6.76]). Significant heterogeneity remained across each analysis. The bullying perpetration and suicidal behavior effect sizes were moderated by the study’s country of origin; the bully/victim status and suicidal ideation results were moderated by bullying assessment method. CONCLUSIONS Findings demonstrated that involvement in bullying in any capacity is associated with suicidal ideation and behavior. Future research should address mental health implications of bullying involvement to prevent suicidal ideation/behavior. PMID:25560447

The effectiveness and safety of antifibrinolytics in patients with acute intracranial haemorrhage: statistical analysis plan for an individual patient data meta-analysis

OpenAIRE

Ker, Katharine; Prieto-Merino, David; Sprigg, Nikola; Mahmood, Abda; Bath, Philip; Kang Law, Zhe; Flaherty, Katie; Roberts, Ian

2017-01-01

Introduction: The Antifibrinolytic Trialists Collaboration aims to increase knowledge about the effectiveness and safety of antifibrinolytic treatment by conducting individual patient data (IPD) meta-analyses of randomised trials. This article presents the statistical analysis plan for an IPD meta-analysis of the effects of antifibrinolytics for acute intracranial haemorrhage. Methods: The protocol for the IPD meta-analysis has been registered with PROSPERO (CRD42016052155). We will conduct a...

Cell-Free DNA in Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Spindler, Karen-Lise G; Boysen, Anders K; Pallisgård, Niels; Johansen, Julia S; Tabernero, Josep; Sørensen, Morten M; Jensen, Benny V; Hansen, Torben F; Sefrioui, David; Andersen, Rikke F; Brandslund, Ivan; Jakobsen, Anders

2017-09-01

systemic therapy. Small fragments of circulating cell-free DNA (cfDNA) can be measured in a simple blood sample. This report presents the first meta-analysis of the prognostic value of total cfDNA measurement in patients with metastatic colorectal cancer. Data from 1,076 patients confirmed that patients with the lowest pre-treatment levels of cfDNA had a significantly higher chance of longer survival than those with higher levels. Cell-free DNA analysis can also be used for detection of tumor-specific mutations, and hold potential as a valuable tool in colorectal cancer treatment. © AlphaMed Press 2017.

Contribution to the sample mean plot for graphical and numerical sensitivity analysis

International Nuclear Information System (INIS)

Bolado-Lavin, R.; Castaings, W.; Tarantola, S.

2009-01-01

The contribution to the sample mean plot, originally proposed by Sinclair, is revived and further developed as practical tool for global sensitivity analysis. The potentials of this simple and versatile graphical tool are discussed. Beyond the qualitative assessment provided by this approach, a statistical test is proposed for sensitivity analysis. A case study that simulates the transport of radionuclides through the geosphere from an underground disposal vault containing nuclear waste is considered as a benchmark. The new approach is tested against a very efficient sensitivity analysis method based on state dependent parameter meta-modelling

A Bayesian approach to meta-analysis of plant pathology studies.

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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

REAL-TIME ENERGY INFORMATION AND CONSUMER BEHAVIOR: A META-ANALYSIS AND FORECAST

Science.gov (United States)

The meta-analysis of literature and program results will shed light on potential causes of study-to-study variation in information feedback programs and trials. Outputs from the meta-analysis, such as price elasticity, will be used in NEMS to estimate the impact of a nation...

Upward counterfactual thinking and depression: A meta-analysis.

Science.gov (United States)

Broomhall, Anne Gene; Phillips, Wendy J; Hine, Donald W; Loi, Natasha M

2017-07-01

This meta-analysis examined the strength of association between upward counterfactual thinking and depressive symptoms. Forty-two effect sizes from a pooled sample of 13,168 respondents produced a weighted average effect size of r=.26, pdesign (cross-sectional versus longitudinal). Significant effect size heterogeneity was observed across sample types, methods of assessing upward counterfactual thinking, and types of depression scale. Significant positive effects were found in studies that employed samples of bereaved individuals, older adults, terminally ill patients, or university students, but not adolescent mothers or mixed samples. Both number-based and Likert-based upward counterfactual thinking assessments produced significant positive effects, with the latter generating a larger effect. All depression scales produced significant positive effects, except for the Psychiatric Epidemiology Research Interview. Research and theoretical implications are discussed in relation to cognitive theories of depression and the functional theory of upward counterfactual thinking, and important gaps in the extant research literature are identified. Copyright © 2017 Elsevier Ltd. All rights reserved.

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.

Dietary patterns and depression risk: A meta-analysis.

Science.gov (United States)

Li, Ye; Lv, Mei-Rong; Wei, Yan-Jin; Sun, Ling; Zhang, Ji-Xiang; Zhang, Huai-Guo; Li, Bin

2017-07-01

Although some studies have reported potential associations of dietary patterns with depression risk, a consistent perspective hasn't been estimated to date. Therefore, we conducted this meta-analysis to evaluate the relation between dietary patterns and the risk of depression. A literature research was conducted searching MEDLINE and EMBASE databases up to September 2016. In total, 21 studies from ten countries met the inclusion criteria and were included in the present meta-analysis. A dietary pattern characterized by a high intakes of fruit, vegetables, whole grain, fish, olive oil, low-fat dairy and antioxidants and low intakes of animal foods was apparently associated with a decreased risk of depression. A dietary pattern characterized by a high consumption of red and/or processed meat, refined grains, sweets, high-fat dairy products, butter, potatoes and high-fat gravy, and low intakes of fruits and vegetables is associated with an increased risk of depression. The results of this meta-analysis suggest that healthy pattern may decrease the risk of depression, whereas western-style may increase the risk of depression. However, more randomized controlled trails and cohort studies are urgently required to confirm this findings. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

The Review Systematic and Meta Analysis of Prevalence and Causes of Nosocomial Infection in Iran

Directory of Open Access Journals (Sweden)

Pezhman Bagheri

2014-12-01

Full Text Available Background and Aim: The variation of reported nosocomial infection is very high respectively. It seems review systematic and Meta analysis of related documents gives precise estimate of this subject for correct politisize. So tha aim of this study the review systematic and meta analysis of prevalence and causes of nosocomial infection in iran. Materials and Methods: For this study all articles published in Iranian journals and international journals, Final Report of Research Projects, related papers presented at congresses and thesis were reviewed with using standard and sensitive keywords. Then, all articles published between 1997-2010 years that had eligibility Inclusion criteria after quality control, using random model, intered to process of meta-analysis. Results: The finding show that the best estimate of total prevalence of nosocomial infection in Iran is 30.43% and the most common infections of nosocomial infection are respiratory infection 39.4%%, urinary infection 23.88%, bacteremia 21.98% and the most common factors of nosocomial infection are Pseudomonas aeroginosa 26.78%, klebsiella 31.42%, Staphylococcus 23.6% and E.coli 30.93%. The research also found a substantial heterogeneity that using meta regression method the main cause of produce of this heterogeneity, participants people, sample size, average age of the samples, time of study and gender were introduced. Conclusions: The simple review of studied documents in this survey show that prevalence rate of different nosocomial infection in Iran is high relatively. Hence make appropriate and evidence-based educational and control programs to reduce nosocomial infections prevalence rate in Iran should be considered by policy makers.

Thyroid Cytology in India: Contemporary Review and Meta-analysis.

Science.gov (United States)

Agarwal, Shipra; Jain, Deepali

2017-11-01

Fine-needle aspiration cytology (FNAC) is a screening test for triaging thyroid nodules, aiding in subsequent clinical management. However, the advantages have been overshadowed by the multiplicity of reporting systems and a wide range of nomenclature used. The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) was formulated in 2007, to give the world a uniform thyroid cytology reporting system, facilitating easy interpretation by the clinicians. Here, we review the status of thyroid FNAC in India in terms of various reporting systems used including a meta-analysis of the previously published data. An extensive literature search was performed using internet search engines. The reports with detailed classification system used in thyroid cytology were included. The meta-analysis of published data was compared with the implied risk of malignancy by TBSRTC. More than 50 studies were retrieved and evaluated. TBSRTC is currently the most widely used reporting system with different studies showing good efficacy and interobserver concordance. Ancillary techniques have, as of now, limited applicability and acceptability in thyroid cytology in India. Twenty-eight published articles met the criteria for inclusion in the meta-analysis. When compared with TBSRTC recommendations, the meta-analysis showed a higher risk of malignancy for categories I and III. Thyroid FNAC is practiced all over India. TBSRTC has found widespread acceptance, with most institutions using this system for routine thyroid cytology reporting. However, reasons for a high malignancy risk for categories I and III need to be looked into. Various possible contributing factors are discussed in the review.

Methicillin resistant Staphylococcus aureus in Ethiopia: a meta-analysis.

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Eshetie, Setegn; Tarekegn, Fentahun; Moges, Feleke; Amsalu, Anteneh; Birhan, Wubet; Huruy, Kahsay

2016-11-21

The burden of methicillin resistant Staphylococcus aureus is a major public health concern worldwide; however the overall epidemiology of multidrug resistant strains is neither coordinated nor harmonized, particularly in developing countries including Ethiopia. Therefore, the aim of this meta-analysis was to assess the burden of methicillin resistant Staphylococcos aureus and its antibiotic resistance pattern in Ethiopia at large. PubMed, Google Scholar, and lancet databases were searched and a total of 20 studies have been selected for meta-analysis. Six authors have independently extracts data on the prevalence of methicillin resistant Staphylococcus aureus among clinical isolates of Staphylococcus aureus. Statistical analysis was achieved by using Open meta-analyst (version 3.13) and Comprehensive meta-analysis (version 3.3) softwares. The overall prevalence of methicillin resistant Staphylococcus aureus and its antibiotic resistance pattern were pooled by using the forest plot, table and figure with 95% CI. The pooled prevalence of methicillin resistant Staphylococcus aureus was 32.5% (95% CI, 24.1 to 40.9%). Moreover, methicillin resistant Staphylococcus aureus strains were found to be highly resistant to penicillin, ampicillin, erythromycin, and amoxicillin, with a pooled resistance ratio of 99.1, 98.1, 97.2 and 97.1%, respectively. On the other hand, comparably low levels of resistance ratio were noted to vancomycin, 5.3%. The overall burden of methicillin resistant Staphylococcus aureus is considerably high, besides these strains showed extreme resistance to penicillin, ampicillin, erythromycin and amoxicillin. In principle, appropriate use of antibiotics, applying safety precautions are the key to reduce the spread of multidrug resistant strains, methicillin resistant Staphylococcus aureus in particular.

Metallothionein - immunohistochemical cancer biomarker: a meta-analysis.

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Jaromir Gumulec

Full Text Available Metallothionein (MT has been extensively investigated as a molecular marker of various types of cancer. In spite of the fact that numerous reviews have been published in this field, no meta-analytical approach has been performed. Therefore, results of to-date immunohistochemistry-based studies were summarized using meta-analysis in this review. Web of science, PubMed, Embase and CENTRAL databases were searched (up to April 30, 2013 and the eligibility of individual studies and heterogeneity among the studies was assessed. Random and fixed effects model meta-analysis was employed depending on the heterogeneity, and publication bias was evaluated using funnel plots and Egger's tests. A total of 77 studies were included with 8,015 tissue samples (4,631 cases and 3,384 controls. A significantly positive association between MT staining and tumors (vs. healthy tissues was observed in head and neck (odds ratio, OR 9.95; 95% CI 5.82-17.03 and ovarian tumors (OR 7.83; 1.09-56.29, and a negative association was ascertained in liver tumors (OR 0.10; 0.03-0.30. No significant associations were identified in breast, colorectal, prostate, thyroid, stomach, bladder, kidney, gallbladder, and uterine cancers and in melanoma. While no associations were identified between MT and tumor staging, a positive association was identified with the tumor grade (OR 1.58; 1.08-2.30. In particular, strong associations were observed in breast, ovarian, uterine and prostate cancers. Borderline significant association of metastatic status and MT staining were determined (OR 1.59; 1.03-2.46, particularly in esophageal cancer. Additionally, a significant association between the patient prognosis and MT staining was also demonstrated (hazard ratio 2.04; 1.47-2.81. However, a high degree of inconsistence was observed in several tumor types, including colorectal, kidney and prostate cancer. Despite the ambiguity in some tumor types, conclusive results are provided in the tumors of

Visual Task Demands and the Auditory Mismatch Negativity: An Empirical Study and a Meta-Analysis.

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Wiens, Stefan; Szychowska, Malina; Nilsson, Mats E

2016-01-01

Because the auditory system is particularly useful in monitoring the environment, previous research has examined whether task-irrelevant, auditory distracters are processed even if subjects focus their attention on visual stimuli. This research suggests that attentionally demanding visual tasks decrease the auditory mismatch negativity (MMN) to simultaneously presented auditory distractors. Because a recent behavioral study found that high visual perceptual load decreased detection sensitivity of simultaneous tones, we used a similar task (n = 28) to determine if high visual perceptual load would reduce the auditory MMN. Results suggested that perceptual load did not decrease the MMN. At face value, these nonsignificant findings may suggest that effects of perceptual load on the MMN are smaller than those of other demanding visual tasks. If so, effect sizes should differ systematically between the present and previous studies. We conducted a selective meta-analysis of published studies in which the MMN was derived from the EEG, the visual task demands were continuous and varied between high and low within the same task, and the task-irrelevant tones were presented in a typical oddball paradigm simultaneously with the visual stimuli. Because the meta-analysis suggested that the present (null) findings did not differ systematically from previous findings, the available evidence was combined. Results of this meta-analysis confirmed that demanding visual tasks reduce the MMN to auditory distracters. However, because the meta-analysis was based on small studies and because of the risk for publication biases, future studies should be preregistered with large samples (n > 150) to provide confirmatory evidence for the results of the present meta-analysis. These future studies should also use control conditions that reduce confounding effects of neural adaptation, and use load manipulations that are defined independently from their effects on the MMN.

Visual Task Demands and the Auditory Mismatch Negativity: An Empirical Study and a Meta-Analysis

Science.gov (United States)

Wiens, Stefan; Szychowska, Malina; Nilsson, Mats E.

2016-01-01

Because the auditory system is particularly useful in monitoring the environment, previous research has examined whether task-irrelevant, auditory distracters are processed even if subjects focus their attention on visual stimuli. This research suggests that attentionally demanding visual tasks decrease the auditory mismatch negativity (MMN) to simultaneously presented auditory distractors. Because a recent behavioral study found that high visual perceptual load decreased detection sensitivity of simultaneous tones, we used a similar task (n = 28) to determine if high visual perceptual load would reduce the auditory MMN. Results suggested that perceptual load did not decrease the MMN. At face value, these nonsignificant findings may suggest that effects of perceptual load on the MMN are smaller than those of other demanding visual tasks. If so, effect sizes should differ systematically between the present and previous studies. We conducted a selective meta-analysis of published studies in which the MMN was derived from the EEG, the visual task demands were continuous and varied between high and low within the same task, and the task-irrelevant tones were presented in a typical oddball paradigm simultaneously with the visual stimuli. Because the meta-analysis suggested that the present (null) findings did not differ systematically from previous findings, the available evidence was combined. Results of this meta-analysis confirmed that demanding visual tasks reduce the MMN to auditory distracters. However, because the meta-analysis was based on small studies and because of the risk for publication biases, future studies should be preregistered with large samples (n > 150) to provide confirmatory evidence for the results of the present meta-analysis. These future studies should also use control conditions that reduce confounding effects of neural adaptation, and use load manipulations that are defined independently from their effects on the MMN. PMID:26741815

The Relationship between Pay and Job Satisfaction: A Meta-Analysis of the Literature

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Judge, Timothy A.; Piccolo, Ronald F.; Podsakoff, Nathan P.; Shaw, John C.; Rich, Bruce L.

2010-01-01

Whereas the motivational aspects of pay are well-documented, the notion that high pay leads to high levels of satisfaction is not without debate. The current study used meta-analysis to estimate the population correlation between pay level and measures of pay and job satisfaction. Cumulating across 115 correlations from 92 independent samples,…

A Meta-Analysis of Cross Sectional Studies Investigating Language in Maltreated Children

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Lum, Jarrad A. G.; Powell, Martine; Timms, Lydia; Snow, Pamela

2015-01-01

Purpose: In this review article, meta-analysis was used to summarize research investigating language skills in maltreated children. Method: A systematic search of published studies was undertaken. Studies were included in the meta-analysis if they investigated language skills in groups comprising maltreated and nonmaltreated children. Studies were…

Transcriptomic Analysis and Meta-Analysis of Human Granulosa and Cumulus Cells.

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Tanja Burnik Papler

Full Text Available Specific gene expression in oocytes and its surrounding cumulus (CC and granulosa (GC cells is needed for successful folliculogenesis and oocyte maturation. The aim of the present study was to compare genome-wide gene expression and biological functions of human GC and CC. Individual GC and CC were derived from 37 women undergoing IVF procedures. Gene expression analysis was performed using microarrays, followed by a meta-analysis. Results were validated using quantitative real-time PCR. There were 6029 differentially expressed genes (q < 10-4; of which 650 genes had a log2 FC ≥ 2. After the meta-analysis there were 3156 genes differentially expressed. Among these there were genes that have previously not been reported in human somatic follicular cells, like prokineticin 2 (PROK2, higher expressed in GC, and pregnancy up-regulated nonubiquitous CaM kinase (PNCK, higher expressed in CC. Pathways like inflammatory response and angiogenesis were enriched in GC, whereas in CC, cell differentiation and multicellular organismal development were among enriched pathways. In conclusion, transcriptomes of GC and CC as well as biological functions, are distinctive for each cell subpopulation. By describing novel genes like PROK2 and PNCK, expressed in GC and CC, we upgraded the existing data on human follicular biology.

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

Impact of Instructional Decisions on the Effectiveness of Cooperative Learning in Chemistry through Meta-Analysis

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Apugliese, Andrew; Lewis, Scott E.

2017-01-01

Meta-analysis can provide a robust description of the impact of educational reforms and also offer an opportunity to explore the conditions where such reforms are more or less effective. This article describes a meta-analysis on the impact of cooperative learning on students' chemistry understanding. Modifiers in the meta-analysis are purposefully…

Vitamin E and risk of age-related cataract: a meta-analysis.

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Zhang, Yufei; Jiang, Wenjie; Xie, Zhutian; Wu, Wenlong; Zhang, Dongfeng

2015-10-01

We conducted a meta-analysis to evaluate the relationship between vitamin E and age-related cataract (ARC). The fixed- or random-effect model was selected based on heterogeneity. Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was evaluated using Begg's test. The dose-response relationship was assessed by a restricted cubic spline model. Relevant studies were identified by a search of PubMed and the Cochrane Library to May 2014, without language restrictions. Studies involved samples of people of all ages. Dietary vitamin E intake, dietary and supplemental vitamin E intake, and high serum tocopherol levels were significantly associated with decreased risk of ARC, the pooled relative risk was 0·73 (95% CI 0·58, 0·92), 0·86 (95% CI 0·75, 0·99) and 0·77 (95% CI 0·66, 0·91), respectively. Supplemental vitamin E intake was non-significantly associated with ARC risk (relative risk=0·92; 95% CI 0·78, 1·07). The findings from dose-response analysis showed evidence of a non-linear association between dietary vitamin E intake and ARC. The risk of ARC decreased with dietary vitamin E intake from 7 mg/d (relative risk=0·94; 95% CI 0·90, 0·97). The findings of the meta-analysis indicated that dietary vitamin E intake, dietary and supplemental vitamin E intake, and high level of serum tocopherol might be significantly associated with reduced ARC risk.

Occurrence of Phlebitis: A Systematic Review and Meta-analysis.

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Chang, Wen P; Peng, Yu X

Peripheral venous catheters (PVCs) are commonly used in clinical practice. However, varying degrees of phlebitis often occur in patients receiving intravenous injections. The relevant literature suggests that phlebitis occurrence is highly associated with the catheter gauge, insertion site, and catheterization duration. Nevertheless, no meta-analysis has been performed on the influence of these three factors on the occurrence of phlebitis. The objective of this study was to determine whether any significant differences exist in the occurrence of phlebitis between catheters of 20 gauge or smaller and those larger than 20 gauge, between catheters inserted in the antecubital fossa and those inserted in other locations on the upper limbs, or between catheters inserted for more than 96 hours and those inserted for 96 hours or less. Using a systematic approach, we searched for literature published between 2006 and 2017 in the Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, ProQuest, and Cochrane Library databases. We used Comprehensive Meta-analysis Version 2 to perform our meta-analysis. After the screening and review processes, we identified 17 studies that met our selection conditions. Among these studies, 14 contained complete data for meta-analysis. These studies involved 4,343 patients and 5,846 PVCs. Regarding the overall effect size in the meta-analysis, the results of the forest plot comparing catheters of 20 gauge or smaller and those larger than 20 gauge presented a risk ratio (RR) of 0.88 (95% confidence interval [0.67, 1.17], p = .380), indicating no statistically significant difference in the occurrence of phlebitis between catheters of the aforementioned gauges. The results of the forest plot comparing catheters inserted in the antecubital fossa and those inserted in other locations on the upper limbs presented an RR of 1.05 (95% confidence interval [0.82, 1.34], p = .696), indicating no statistically significant difference in

Simulation-based power calculations for planning a two-stage individual participant data meta-analysis.

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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.

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

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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

The Effect of Educational Leadership on Organizational Variables: A Meta-Analysis Study in the Sample of Turkey

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Çogaltay, Nazim; Karadag, Engin

2016-01-01

The purpose of this study is to test the effect of educational leadership on some organizational variables using meta-analysis method. In this context, the results of independent researches were merged together and the hypotheses created within the scope of the study were tested. In order to determine the researches to be included in the study,…

Efficacy of Acupuncture in Reducing Preoperative Anxiety: A Meta-Analysis

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Hyojeong Bae

2014-01-01

Full Text Available Background. Acupuncture has been shown to reduce preoperative anxiety in several previous randomized controlled trials (RCTs. In order to assess the preoperative anxiolytic efficacy of acupuncture therapy, this study conducted a meta-analysis of an array of appropriate studies. Methods. Four electronic databases (MEDLINE, EMBASE, CENTRAL, and CINAHL were searched up to February 2014. In the meta-analysis data were included from RCT studies in which groups receiving preoperative acupuncture treatment were compared with control groups receiving a placebo for anxiety. Results. Fourteen publications (N = 1,034 were included. Six publications, using the State-Trait Anxiety Inventory-State (STAI-S, reported that acupuncture interventions led to greater reductions in preoperative anxiety relative to sham acupuncture (mean difference = 5.63, P < .00001, 95% CI [4.14, 7.11]. Further eight publications, employing visual analogue scales (VAS, also indicated significant differences in preoperative anxiety amelioration between acupuncture and sham acupuncture (mean difference = 19.23, P < .00001, 95% CI [16.34, 22.12]. Conclusions. Acupuncture therapy aiming at reducing preoperative anxiety has a statistically significant effect relative to placebo or nontreatment conditions. Well-designed and rigorous studies that employ large sample sizes are necessary to corroborate this finding.

Identification of cytokinin-responsive genes using microarray meta-analysis and RNA-Seq in Arabidopsis.

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Bhargava, Apurva; Clabaugh, Ivory; To, Jenn P; Maxwell, Bridey B; Chiang, Yi-Hsuan; Schaller, G Eric; Loraine, Ann; Kieber, Joseph J

2013-05-01

Cytokinins are N(6)-substituted adenine derivatives that play diverse roles in plant growth and development. We sought to define a robust set of genes regulated by cytokinin as well as to query the response of genes not represented on microarrays. To this end, we performed a meta-analysis of microarray data from a variety of cytokinin-treated samples and used RNA-seq to examine cytokinin-regulated gene expression in Arabidopsis (Arabidopsis thaliana). Microarray meta-analysis using 13 microarray experiments combined with empirically defined filtering criteria identified a set of 226 genes differentially regulated by cytokinin, a subset of which has previously been validated by other methods. RNA-seq validated about 73% of the up-regulated genes identified by this meta-analysis. In silico promoter analysis indicated an overrepresentation of type-B Arabidopsis response regulator binding elements, consistent with the role of type-B Arabidopsis response regulators as primary mediators of cytokinin-responsive gene expression. RNA-seq analysis identified 73 cytokinin-regulated genes that were not represented on the ATH1 microarray. Representative genes were verified using quantitative reverse transcription-polymerase chain reaction and NanoString analysis. Analysis of the genes identified reveals a substantial effect of cytokinin on genes encoding proteins involved in secondary metabolism, particularly those acting in flavonoid and phenylpropanoid biosynthesis, as well as in the regulation of redox state of the cell, particularly a set of glutaredoxin genes. Novel splicing events were found in members of some gene families that are known to play a role in cytokinin signaling or metabolism. The genes identified in this analysis represent a robust set of cytokinin-responsive genes that are useful in the analysis of cytokinin function in plants.

Efficacy of metformin in the treatment of NIDDM. Meta-analysis

DEFF Research Database (Denmark)

Johansen, K

1999-01-01

OBJECTIVE: The results differ concerning randomized controlled trials of the effects of metformin on blood glucose regulation and body weight. To get a systematic overview, a meta-analysis of the efficacy of metformin was performed by comparing metformin with placebo and sulfonylurea. RESEARCH...... DESIGN AND METHODS: All randomized controlled trials published since 1957 were selected by searching the Current List of Medical Literature, Cumulated Index Medicus, Medline, and Embase, Meta-analysis was performed calculating weighted mean difference (WMD) of fasting blood glucose, glycosylated...

Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

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Yin, Xin-Hai; Huang, Guang-Lei; Lin, Du-Ren; Wan, Cheng-Cheng; Wang, Ya-Dong; Song, Ju-Kun; Xu, Ping

2015-01-01

Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk. PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs) with corresponding 95% confidence intervals (CIs) were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed. Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15). Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed. The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

Exposure to fluoride in drinking water and hip fracture risk: a meta-analysis of observational studies.

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Xin-Hai Yin

Full Text Available Many observational studies have shown that exposure to fluoride in drinking water is associated with hip fracture risk. However, the findings are varied or even contradictory. In this work, we performed a meta-analysis to assess the relationship between fluoride exposure and hip fracture risk.PubMed and EMBASE databases were searched to identify relevant observational studies from the time of inception until March 2014 without restrictions. Data from the included studies were extracted and analyzed by two authors. Summary relative risks (RRs with corresponding 95% confidence intervals (CIs were pooled using random- or fixed-effects models as appropriate. Sensitivity analyses and meta-regression were conducted to explore possible explanations for heterogeneity. Finally, publication bias was assessed.Fourteen observational studies involving thirteen cohort studies and one case-control study were included in the meta-analysis. Exposure to fluoride in drinking water does not significantly increase the incidence of hip fracture (RRs, 1.05; 95% CIs, 0.96-1.15. Sensitivity analyses based on adjustment for covariates, effect measure, country, sex, sample size, quality of Newcastle-Ottawa Scale scores, and follow-up period validated the strength of the results. Meta-regression showed that country, gender, quality of Newcastle-Ottawa Scale scores, adjustment for covariates and sample size were not sources of heterogeneity. Little evidence of publication bias was observed.The present meta-analysis suggests that chronic fluoride exposure from drinking water does not significantly increase the risk of hip fracture. Given the potential confounding factors and exposure misclassification, further large-scale, high-quality studies are needed to evaluate the association between exposure to fluoride in drinking water and hip fracture risk.

Meta-analysis of 32 genome-wide linkage studies of schizophrenia

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Ng, MYM; Levinson, DF; Faraone, SV; Suarez, BK; DeLisi, LE; Arinami, T; Riley, B; Paunio, T; Pulver, AE; Irmansyah; Holmans, PA; Escamilla, M; Wildenauer, DB; Williams, NM; Laurent, C; Mowry, BJ; Brzustowicz, LM; Maziade, M; Sklar, P; Garver, DL; Abecasis, GR; Lerer, B; Fallin, MD; Gurling, HMD; Gejman, PV; Lindholm, E; Moises, HW; Byerley, W; Wijsman, EM; Forabosco, P; Tsuang, MT; Hwu, H-G; Okazaki, Y; Kendler, KS; Wormley, B; Fanous, A; Walsh, D; O’Neill, FA; Peltonen, L; Nestadt, G; Lasseter, VK; Liang, KY; Papadimitriou, GM; Dikeos, DG; Schwab, SG; Owen, MJ; O’Donovan, MC; Norton, N; Hare, E; Raventos, H; Nicolini, H; Albus, M; Maier, W; Nimgaonkar, VL; Terenius, L; Mallet, J; Jay, M; Godard, S; Nertney, D; Alexander, M; Crowe, RR; Silverman, JM; Bassett, AS; Roy, M-A; Mérette, C; Pato, CN; Pato, MT; Roos, J Louw; Kohn, Y; Amann-Zalcenstein, D; Kalsi, G; McQuillin, A; Curtis, D; Brynjolfson, J; Sigmundsson, T; Petursson, H; Sanders, AR; Duan, J; Jazin, E; Myles-Worsley, M; Karayiorgou, M; Lewis, CM

2009-01-01

A genome scan meta-analysis (GSMA) was carried out on 32 independent genome-wide linkage scan analyses that included 3255 pedigrees with 7413 genotyped cases affected with schizophrenia (SCZ) or related disorders. The primary GSMA divided the autosomes into 120 bins, rank-ordered the bins within each study according to the most positive linkage result in each bin, summed these ranks (weighted for study size) for each bin across studies and determined the empirical probability of a given summed rank (PSR) by simulation. Suggestive evidence for linkage was observed in two single bins, on chromosomes 5q (142-168 Mb) and 2q (103-134 Mb). Genome-wide evidence for linkage was detected on chromosome 2q (119-152 Mb) when bin boundaries were shifted to the middle of the previous bins. The primary analysis met empirical criteria for ‘aggregate’ genome-wide significance, indicating that some or all of 10 bins are likely to contain loci linked to SCZ, including regions of chromosomes 1, 2q, 3q, 4q, 5q, 8p and 10q. In a secondary analysis of 22 studies of European-ancestry samples, suggestive evidence for linkage was observed on chromosome 8p (16-33 Mb). Although the newer genome-wide association methodology has greater power to detect weak associations to single common DNA sequence variants, linkage analysis can detect diverse genetic effects that segregate in families, including multiple rare variants within one locus or several weakly associated loci in the same region. Therefore, the regions supported by this meta-analysis deserve close attention in future studies. PMID:19349958

Meta-análise em pesquisas científicas: enfoque em metodologias Meta analysis in scientific research: a methodological approach

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P.A. Lovatto

2007-07-01

Full Text Available Este texto descreve os princípios básicos de sistematização com enfoque em meta-análise. É apresentado o estado da arte da meta-análise, recuperando informações de sua evolução e metodologias básicas para sua realização. São descritos seus antecedentes históricos, os limites das abordagens clássicas de revisão de literatura, as bases conceituais, os objetivos e justificativas. É indicada uma metodologia geral para realização da meta-análise. São apresentados os critérios para a definição dos objetivos. São descritos os procedimentos de sistematização das informações e gestão de base bibliográfica de dados destinada aos estudos meta-analíticos (seleção, codificação, filtragem de dados. São apresentadas as análises mais comuns (gráfica, ponderações, a escolha do modelo estatístico (um fator explicativo qualitativo, um efeito qualitativo ou quantitativo, os fatores de interferência, os procedimentos pós-analíticos (variações residuais, heterogeneidade entre resultados. Em síntese, este texto mostra que a meta-análise é superior às formas tradicionais de revisão de literatura por estimar com maior precisão os efeitos dos tratamentos, ajustando-os para a heterogeneidade experimental. No entanto, a meta-análise exige os efeitos na sistematização e análise dos resultados da pesquisa.This text describes a basic approach of systematization with focus on meta-analysis. It is presented the art state of the meta-analysis, recovering information of its evolution and basic methodologies for its accomplishment. In this text are described the historical antecedents of meta-analysis, the limits of the classic approaches of literature review, the conceptual bases and the objectives. It is indicated a general methodology for meta-analysis procedures. The criteria for the definition of the objectives are presented. The procedures of the systematization and management of bibliographical data base selected to

Prevalence of rapid eye movement sleep behavior disorder (RBD) in Parkinson's disease: a meta and meta-regression analysis.

Science.gov (United States)

Zhang, Xiaona; Sun, Xiaoxuan; Wang, Junhong; Tang, Liou; Xie, Anmu

2017-01-01

Rapid eye movement sleep behavior disorder (RBD) is thought to be one of the most frequent preceding symptoms of Parkinson's disease (PD). However, the prevalence of RBD in PD stated in the published studies is still inconsistent. We conducted a meta and meta-regression analysis in this paper to estimate the pooled prevalence. We searched the electronic databases of PubMed, ScienceDirect, EMBASE and EBSCO up to June 2016 for related articles. STATA 12.0 statistics software was used to calculate the available data from each research. The prevalence of RBD in PD patients in each study was combined to a pooled prevalence with a 95 % confidence interval (CI). Subgroup analysis and meta-regression analysis were performed to search for the causes of the heterogeneity. A total of 28 studies with 6869 PD cases were deemed eligible and included in our meta-analysis based on the inclusion and exclusion criteria. The pooled prevalence of RBD in PD was 42.3 % (95 % CI 37.4-47.1 %). In subgroup analysis and meta-regression analysis, we found that the important causes of heterogeneity were the diagnosis criteria of RBD and age of PD patients (P = 0.016, P = 0.019, respectively). The results indicate that nearly half of the PD patients are suffering from RBD. Older age and longer duration are risk factors for RBD in PD. We can use the minimal diagnosis criteria for RBD according to the International Classification of Sleep Disorders to diagnose RBD patients in our daily work if polysomnography is not necessary.

Meta-analysis of graduated driver licensing laws.

Science.gov (United States)

2015-11-01

The objective of the present study was to assess the effectiveness of GDL programs for reducing total, injury, and fatal crashes among drivers 15 to 20 years old by conducting a meta-analysis of GDL research since 2001 that evaluated the effectivenes...

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

Relaxation training for anxiety: a ten-years systematic review with meta-analysis.

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Manzoni, Gian Mauro; Pagnini, Francesco; Castelnuovo, Gianluca; Molinari, Enrico

2008-06-02

Relaxation training is a common treatment for anxiety problems. Lacking is a recent quantitative meta-analysis that enhances understanding of the variability and clinical significance of anxiety reduction outcomes after relaxation treatment. All studies (1997-2007), both RCT, observational and without control group, evaluating the efficacy of relaxation training (Jacobson's progressive relaxation, autogenic training, applied relaxation and meditation) for anxiety problems and disorders were identified by comprehensive electronic searches with Pubmed, Psychinfo and Cochrane Registers, by checking references of relevant studies and of other reviews. Our primary outcome was anxiety measured with psychometric questionnaires. Meta-analysis was undertaken synthesizing the data from all trials, distinguishing within and between effect sizes. 27 studies qualified for the inclusion in the meta-analysis. As hypothesized, relaxation training showed a medium-large effect size in the treatment of anxiety. Cohen's d was .57 (95% CI: .52 to .68) in the within analysis and .51 (95% CI: .46 to .634) in the between group analysis. Efficacy was higher for meditation, among volunteers and for longer treatments. Implications and limitations are discussed. The results show consistent and significant efficacy of relaxation training in reducing anxiety. This meta-analysis extends the existing literature through facilitation of a better understanding of the variability and clinical significance of anxiety improvement subsequent to relaxation training.

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

A meta-frontier approach for causal inference in productivity analysis

DEFF Research Database (Denmark)

Henningsen, Arne; Mpeta, Daniel F.; Adem, Anwar S.

(2012) and create a meta-frontier in order to estimate the effects of participation on the farms’ meta-technology ratio, their group technical efficiency, and their meta-technology technical efficiency. The empirical analysis uses a cross-sectional data set from sunflower farmers in Tanzania, where some...... by the contractor’s provision of (additional) extension service and seeds of high-yielding varieties to the contract farmers....

Association Between Blood Glucose and Functional Outcome in Intracerebral Hemorrhage: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Zheng, Jun; Yu, Zhiyuan; Ma, Lu; Guo, Rui; Lin, Sen; You, Chao; Li, Hao

2018-03-16

Intracerebral hemorrhage (ICH) is a devastating subtype of stroke. Patients with ICH have poor functional outcomes. The association between blood glucose level and functional outcome in ICH remains unclear. This systematic review and meta-analysis aimed to investigate the association between blood glucose level and functional outcomes in patients with ICH. Literature was searched systemically in PubMed, EMBASE, Web of Science, and Cochrane Library. Published cohort studies evaluating the association between blood glucose and functional outcome in patients with ICH were included. This meta-analysis was performed using odds ratios (ORs) and 95% confidence intervals (CIs). A total of 16 studies were included in our meta-analysis. Our data show that hyperglycemia defined by cutoff values was significantly associated with unfavorable functional outcome (OR, 1.80; 95% CI, 1.36-2.39; P analysis also suggested a significant association between increased blood glucose levels and functional outcomes (OR, 1.05; 95% CI, 1.03-1.07; P functional outcome in ICH. Further studies with larger sample sizes, more time points, and longer follow-up times are necessary to confirm this association. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Meta-Analysis: Application to Clinical Dentistry and Dental Education.

Science.gov (United States)

Cohen, Peter A.

1992-01-01

Meta-analysis is proposed as an effective alternative to conventional narrative review for extracting trends from research findings. This type of analysis is explained, advantages over more traditional review techniques are discussed, basic procedures and limitations are outlined, and potential applications in dental education and clinical…

Simulation-based training for nurses: Systematic review and meta-analysis.

Science.gov (United States)

Hegland, Pål A; Aarlie, Hege; Strømme, Hilde; Jamtvedt, Gro

2017-07-01

Simulation-based training is a widespread strategy to improve health-care quality. However, its effect on registered nurses has previously not been established in systematic reviews. The aim of this systematic review is to evaluate effect of simulation-based training on nurses' skills and knowledge. We searched CDSR, DARE, HTA, CENTRAL, CINAHL, MEDLINE, Embase, ERIC, and SveMed+ for randomised controlled trials (RCT) evaluating effect of simulation-based training among nurses. Searches were completed in December 2016. Two reviewers independently screened abstracts and full-text, extracted data, and assessed risk of bias. We compared simulation-based training to other learning strategies, high-fidelity simulation to other simulation strategies, and different organisation of simulation training. Data were analysed through meta-analysis and narrative syntheses. GRADE was used to assess the quality of evidence. Fifteen RCTs met the inclusion criteria. For the comparison of simulation-based training to other learning strategies on nurses' skills, six studies in the meta-analysis showed a significant, but small effect in favour of simulation (SMD -1.09, CI -1.72 to -0.47). There was large heterogeneity (I 2 85%). For the other comparisons, there was large between-study variation in results. The quality of evidence for all comparisons was graded as low. The effect of simulation-based training varies substantially between studies. Our meta-analysis showed a significant effect of simulation training compared to other learning strategies, but the quality of evidence was low indicating uncertainty. Other comparisons showed inconsistency in results. Based on our findings simulation training appears to be an effective strategy to improve nurses' skills, but further good-quality RCTs with adequate sample sizes are needed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Are Parents' Gender Schemas Related to Their Children's Gender-Related Cognitions? A Meta-Analysis.

Science.gov (United States)

Tenenbaum, Harriet R.; Leaper, Campbell

2002-01-01

Used meta-analysis to examine relationship of parents' gender schemas and their offspring's gender-related cognitions, with samples ranging in age from infancy through early adulthood. Found a small but meaningful effect size (r=.16) indicating a positive correlation between parent gender schema and offspring measures. Effect sizes were influenced…

The countermovement jump to monitor neuromuscular status: A meta-analysis.

Science.gov (United States)

Claudino, João Gustavo; Cronin, John; Mezêncio, Bruno; McMaster, Daniel Travis; McGuigan, Michael; Tricoli, Valmor; Amadio, Alberto Carlos; Serrão, Julio Cerca

2017-04-01

The primary objective of this meta-analysis was to compare countermovement jump (CMJ) performance in studies that reported the highest value as opposed to average value for the purposes of monitoring neuromuscular status (i.e., fatigue and supercompensation). The secondary aim was to determine the sensitivity of the dependent variables. Systematic review with meta-analysis. The meta-analysis was conducted on the highest or average of a number of CMJ variables. Multiple literature searches were undertaken in Pubmed, Scopus, and Web of Science to identify articles utilizing CMJ to monitor training status. Effect sizes (ES) with 95% confidence interval (95% CI) were calculated using the mean and standard deviation of the pre- and post-testing data. The coefficient of variation (CV) with 95% CI was also calculated to assess the level of instability of each variable. Heterogeneity was assessed using a random-effects model. 151 articles were included providing a total of 531 ESs for the meta-analyses; 85.4% of articles used highest CMJ height, 13.2% used average and 1.3% used both when reporting changes in CMJ performance. Based on the meta-analysis, average CMJ height was more sensitive than highest CMJ height in detecting CMJ fatigue and supercompensation. Furthermore, other CMJ variables such as peak power, mean power, peak velocity, peak force, mean impulse, and power were sensitive in tracking the supercompensation effects of training. The average CMJ height was more sensitive than highest CMJ height in monitoring neuromuscular status; however, further investigation is needed to determine the sensitivity of other CMJ performance variables. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

A Meta-Analysis on Unconscious Thought Effects

NARCIS (Netherlands)

Strick, M.A.; Dijksterhuis, A.J.; Bos, M.W.; Sjoerdsma, A.; Baaren, R.B. van; Nordgren, L.F.

2011-01-01

A meta-analysis was performed on the unconscious thought effect (UTE). All available published and unpublished data on unconscious thought were included. Our aims were to provide a statistically robust estimate of the effect size of the UTE, to identify significant moderators, and to

A Meta-Analysis of Advanced Organizer Studies.

Science.gov (United States)

Stone, Carol Leth

1983-01-01

Twenty-nine reports yielding 112 studies were analyzed with Glass's meta-analysis technique, and results were compared with predictions from Ausubel's model of assimilative learning. Overall, advance organizers were shown to be associated with increased learning and retention of material to be learned. (Author)

New trends in gender and mathematics performance: a meta-analysis.

Science.gov (United States)

Lindberg, Sara M; Hyde, Janet Shibley; Petersen, Jennifer L; Linn, Marcia C

2010-11-01

In this article, we use meta-analysis to analyze gender differences in recent studies of mathematics performance. First, we meta-analyzed data from 242 studies published between 1990 and 2007, representing the testing of 1,286,350 people. Overall, d = 0.05, indicating no gender difference, and variance ratio = 1.08, indicating nearly equal male and female variances. Second, we analyzed data from large data sets based on probability sampling of U.S. adolescents over the past 20 years: the National Longitudinal Surveys of Youth, the National Education Longitudinal Study of 1988, the Longitudinal Study of American Youth, and the National Assessment of Educational Progress. Effect sizes for the gender difference ranged between -0.15 and +0.22. Variance ratios ranged from 0.88 to 1.34. Taken together, these findings support the view that males and females perform similarly in mathematics.

Voxel-Based Morphometry ALE meta-analysis of Bipolar Disorder

Science.gov (United States)

Magana, Omar; Laird, Robert

2012-03-01

A meta-analysis was performed independently to view the changes in gray matter (GM) on patients with Bipolar disorder (BP). The meta-analysis was conducted on a Talairach Space using GingerALE to determine the voxels and their permutation. In order to achieve the data acquisition, published experiments and similar research studies were uploaded onto the online Voxel-Based Morphometry database (VBM). By doing so, coordinates of activation locations were extracted from Bipolar disorder related journals utilizing Sleuth. Once the coordinates of given experiments were selected and imported to GingerALE, a Gaussian was performed on all foci points to create the concentration points of GM on BP patients. The results included volume reductions and variations of GM between Normal Healthy controls and Patients with Bipolar disorder. A significant amount of GM clusters were obtained in Normal Healthy controls over BP patients on the right precentral gyrus, right anterior cingulate, and the left inferior frontal gyrus. In future research, more published journals could be uploaded onto the database and another VBM meta-analysis could be performed including more activation coordinates or a variation of age groups.

Genome-Wide Meta-Analysis of Sciatica in Finnish Population.

Science.gov (United States)

Lemmelä, Susanna; Solovieva, Svetlana; Shiri, Rahman; Benner, Christian; Heliövaara, Markku; Kettunen, Johannes; Anttila, Verneri; Ripatti, Samuli; Perola, Markus; Seppälä, Ilkka; Juonala, Markus; Kähönen, Mika; Salomaa, Veikko; Viikari, Jorma; Raitakari, Olli T; Lehtimäki, Terho; Palotie, Aarno; Viikari-Juntura, Eira; Husgafvel-Pursiainen, Kirsti

2016-01-01

Sciatica or the sciatic syndrome is a common and often disabling low back disorder in the working-age population. It has a relatively high heritability but poorly understood molecular mechanisms. The Finnish population is a genetic isolate where small founder population and bottleneck events have led to enrichment of certain rare and low frequency variants. We performed here the first genome-wide association (GWAS) and meta-analysis of sciatica. The meta-analysis was conducted across two GWAS covering 291 Finnish sciatica cases and 3671 controls genotyped and imputed at 7.7 million autosomal variants. The most promising loci (psciatica patients and 18,489 controls. We identified five intragenic variants, with relatively low frequencies, at two novel loci associated with sciatica at genome-wide significance. These included chr9:14344410:I (rs71321981) at 9p22.3 (NFIB gene; p = 1.30x10-8, MAF = 0.08) and four variants at 15q21.2: rs145901849, rs80035109, rs190200374 and rs117458827 (MYO5A; p = 1.34x10-8, MAF = 0.06; p = 2.32x10-8, MAF = 0.07; p = 3.85x10-8, MAF = 0.06; p = 4.78x10-8, MAF = 0.07, respectively). The most significant association in the meta-analysis, a single base insertion rs71321981 within the regulatory region of the transcription factor NFIB, replicated in an independent Finnish population sample (p = 0.04). Despite identifying 15q21.2 as a promising locus, we were not able to replicate it. It was differentiated; the lead variants within 15q21.2 were more frequent in Finland (6-7%) than in other European populations (1-2%). Imputation accuracies of the three significantly associated variants (chr9:14344410:I, rs190200374, and rs80035109) were validated by genotyping. In summary, our results suggest a novel locus, 9p22.3 (NFIB), which may be involved in susceptibility to sciatica. In addition, another locus, 15q21.2, emerged as a promising one, but failed to replicate.

Bayesian nonparametric meta-analysis using Polya tree mixture models.

Science.gov (United States)

Branscum, Adam J; Hanson, Timothy E

2008-09-01

Summary. A common goal in meta-analysis is estimation of a single effect measure using data from several studies that are each designed to address the same scientific inquiry. Because studies are typically conducted in geographically disperse locations, recent developments in the statistical analysis of meta-analytic data involve the use of random effects models that account for study-to-study variability attributable to differences in environments, demographics, genetics, and other sources that lead to heterogeneity in populations. Stemming from asymptotic theory, study-specific summary statistics are modeled according to normal distributions with means representing latent true effect measures. A parametric approach subsequently models these latent measures using a normal distribution, which is strictly a convenient modeling assumption absent of theoretical justification. To eliminate the influence of overly restrictive parametric models on inferences, we consider a broader class of random effects distributions. We develop a novel hierarchical Bayesian nonparametric Polya tree mixture (PTM) model. We present methodology for testing the PTM versus a normal random effects model. These methods provide researchers a straightforward approach for conducting a sensitivity analysis of the normality assumption for random effects. An application involving meta-analysis of epidemiologic studies designed to characterize the association between alcohol consumption and breast cancer is presented, which together with results from simulated data highlight the performance of PTMs in the presence of nonnormality of effect measures in the source population.

Self-concept and academic achievement: a meta-analysis of longitudinal relations.

Science.gov (United States)

Huang, Chiungjung

2011-10-01

The relation between self-concept and academic achievement was examined in 39 independent and longitudinal samples through the integration of meta-analysis and path analysis procedures. For relations with more than 3 independent samples, the mean observed correlations ranged from .20 to .27 between prior self-concept and subsequent academic achievement and from .19 to .25 between prior academic achievement and subsequent self-concept. Globality/specificity of self-concept was the only significant moderating factor in the relation between (a) prior self-concept and subsequent academic achievement and (b) prior academic achievement and subsequent self-concept. As high self-concept is related to high academic performance and vice-versa, intervention programs that combine self-enhancement and skill development should be integrated. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Meta-analysis of the technical performance of an imaging procedure: guidelines and statistical methodology.

Science.gov (United States)

Huang, Erich P; Wang, Xiao-Feng; Choudhury, Kingshuk Roy; McShane, Lisa M; Gönen, Mithat; Ye, Jingjing; Buckler, Andrew J; Kinahan, Paul E; Reeves, Anthony P; Jackson, Edward F; Guimaraes, Alexander R; Zahlmann, Gudrun

2015-02-01

Medical imaging serves many roles in patient care and the drug approval process, including assessing treatment response and guiding treatment decisions. These roles often involve a quantitative imaging biomarker, an objectively measured characteristic of the underlying anatomic structure or biochemical process derived from medical images. Before a quantitative imaging biomarker is accepted for use in such roles, the imaging procedure to acquire it must undergo evaluation of its technical performance, which entails assessment of performance metrics such as repeatability and reproducibility of the quantitative imaging biomarker. Ideally, this evaluation will involve quantitative summaries of results from multiple studies to overcome limitations due to the typically small sample sizes of technical performance studies and/or to include a broader range of clinical settings and patient populations. This paper is a review of meta-analysis procedures for such an evaluation, including identification of suitable studies, statistical methodology to evaluate and summarize the performance metrics, and complete and transparent reporting of the results. This review addresses challenges typical of meta-analyses of technical performance, particularly small study sizes, which often causes violations of assumptions underlying standard meta-analysis techniques. Alternative approaches to address these difficulties are also presented; simulation studies indicate that they outperform standard techniques when some studies are small. The meta-analysis procedures presented are also applied to actual [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) test-retest repeatability data for illustrative purposes. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

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).

Music therapy research in the NICU: an updated meta-analysis.

Science.gov (United States)

Standley, Jayne

2012-01-01

To provide an overview of developmental and medical benefits of music therapy for preterm infants. Meta-analysis. Empirical music studies with preterm infants in the neonatal intensive care unit (NICU). Evidence-based NICU music therapy (NICU -MT ) was highly beneficial with an overall large significant effect size (Cohen's d = 0.82). Effects because of music were consistently in a positive direction. Results of the current analysis replicated findings of a prior meta-analysis and included extended use of music.(1) Benefits were greatest for live music therapy (MT ) and for use early in the infant's NICU stay (birth weight music listening for pacification, music reinforcement of sucking, and music pacification as the basis for multilayered, multimodal stimulation.

Multiple Sclerosis Increases Fracture Risk: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Guixian Dong

2015-01-01

Full Text Available Purpose. The association between multiple sclerosis (MS and fracture risk has been reported, but results of previous studies remain controversial and ambiguous. To assess the association between MS and fracture risk, a meta-analysis was performed. Method. Based on comprehensive searches of the PubMed, Embase, and Web of Science, we identified outcome data from all articles estimating the association between MS and fracture risk. The pooled risk ratios (RRs with 95% confidence intervals (CIs were calculated. Results. A significant association between MS and fracture risk was found. This result remained statistically significant when the adjusted RRs were combined. Subgroup analysis stratified by the site of fracture suggested significant associations between MS and tibia fracture risk, femur fracture risk, hip fracture risk, pelvis fracture risk, vertebrae fracture risk, and humerus fracture risk. In the subgroup analysis by gender, female MS patients had increased fracture risk. When stratified by history of drug use, use of antidepressants, hypnotics/anxiolytics, anticonvulsants, and glucocorticoids increased the risk of fracture risk in MS patients. Conclusions. This meta-analysis demonstrated that MS was significantly associated with fracture risk.

Game-based digital interventions for depression therapy: a systematic review and meta-analysis.

Science.gov (United States)

Li, Jinhui; Theng, Yin-Leng; Foo, Schubert

2014-08-01

The aim of this study was to review the existing literature on game-based digital interventions for depression systematically and examine their effectiveness through a meta-analysis of randomized controlled trials (RCTs). Database searching was conducted using specific search terms and inclusion criteria. A standard meta-analysis was also conducted of available RCT studies with a random effects model. The standard mean difference (Cohen's d) was used to calculate the effect size of each study. Nineteen studies were included in the review, and 10 RCTs (eight studies) were included in the meta-analysis. Four types of game interventions-psycho-education and training, virtual reality exposure therapy, exercising, and entertainment-were identified, with various types of support delivered and populations targeted. The meta-analysis revealed a moderate effect size of the game interventions for depression therapy at posttreatment (d=-0.47 [95% CI -0.69 to -0.24]). A subgroup analysis showed that interventions based on psycho-education and training had a smaller effect than those based on the other forms, and that self-help interventions yielded better outcomes than supported interventions. A higher effect was achieved when a waiting list was used as the control. The review and meta-analysis support the effectiveness of game-based digital interventions for depression. More large-scale, high-quality RCT studies with sufficient long-term data for treatment evaluation are needed.

Meta-analysis: Risk of dry mouth with second generation antidepressants.

Science.gov (United States)

Cappetta, Kiley; Beyer, Chad; Johnson, Jessica A; Bloch, Michael H

2018-06-08

The goal of this meta-analysis was to quantify the risk of dry mouth associated with commonly prescribed antidepressant agents and examine the potential implications of medication class, dose, and pharmacodynamics and dose on risk of treatment-induced dry mouth. A PubMed search was conducted to identify double-blind, randomized, placebo-controlled trials examining the efficacy and tolerability of second generation antidepressant medications for adults with depressive disorders, anxiety disorders, and OCD. A random-effects meta-analysis was used to quantify the pooled risk ratio of treatment-emergent dry mouth with second generation antidepressants compared to placebo. Stratified subgroup analysis and meta-regression was utilized to further examine the effects antidepressant agent, class, dosage, indication, and receptor affinity profile on the measured risk of dry mouth. 99 trials involving 20,868 adults. SNRIs (Relative Risk (RR)=2.24, 95% Confidence Interval (CI): 1.95-2.58, z=11.2, pz=5.8, pz=10.32, pz=5.85, pz=3.26, p=0.001) and Alpha-2 (PE=0.49, 95% CI: 0.22-0.75, z=3.64, pz=2.10, p<0.05) was significantly associated with increased risk of dry mouth. The current meta-analysis suggests that SSRIs, SNRIs, and atypical antidepressants are all associated with varying degrees of increased risk of dry mouth. SNRIs were associated with a significantly greater risk of dry mouth compared to SSRIs. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of Desflurane versus Sevoflurane in Pediatric Anesthesia: A Meta-Analysis.

Science.gov (United States)

He, Jiaxuan; Zhang, Yong; Xue, Rongliang; Lv, Jianrui; Ding, Xiaoying; Zhang, Zhenni

2015-01-01

To compare the effect of desflurane versus sevoflurane in pediatric anesthesia by conducting meta-analysis. Studies were searched from PubMed, Medline, Springer, Elsevier Science Direct, Cochrane Library and Google Scholar up to July 2014. Weighted mean difference (WMD) or risk ratio (RR) and 95% confidence intervals (CIs) were considered as effect sizes. Heterogeneity across studies was assessed by Cochran Q test and I2 statistic. The random effects model was performed in the meta-analysis when heterogeneity was observed, or the fixed effect model was used. Review Manager 5.1 software was applied for the meta-analysis. A total of 11 studies (13 comparisons) involving 1,273 objects were included in this meta-analysis. No heterogeneity was observed between studies for any comparison but for postoperative extubation time. The results showed significant differences between desflurane and sevoflurane groups for postoperative extubation time (WMD = -3.87, 95%CI = -6.14 to -1.60, P 0.05) were detected for discharge from the recovery room, oculocardiac reflex, nausea and vomiting and severe pain. Desflurane may have less adverse effects than sevoflurane when used in pediatric anesthesia with significantly shorter postoperative extubation time, eye opening time and awakening time as well as slighter agitation.

Multivariate Meta-Analysis Using Individual Participant Data

Science.gov (United States)

Riley, R. D.; Price, M. J.; Jackson, D.; Wardle, M.; Gueyffier, F.; Wang, J.; Staessen, J. A.; White, I. R.

2015-01-01

When combining results across related studies, a multivariate meta-analysis allows the joint synthesis of correlated effect estimates from multiple outcomes. Joint synthesis can improve efficiency over separate univariate syntheses, may reduce selective outcome reporting biases, and enables joint inferences across the outcomes. A common issue is…

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 =

Prevalence of Nontuberculous Mycobacteria (NTM in Iranian Clinical Specimens: Systematic Review and Meta-Analysis

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Azad Khaledi

2017-01-01

Full Text Available Background:    Although, nontuberculous mycobacteria can cause disease in different organisms, they usually are not reported in most countries because scientists in general consider them as non-pathogens. But, increasing nontuberculous mycobacteria diseases occurrence has changed this belief. Nevertheless, there is no meta-analysis review about prevalence of nontuberculous mycobacteria in Iran. Methods:   Any data about prevalence of nontuberculous mycobacteria in clinical specimens in Iran were retrieved by searching data bases such as Pub Med, MEDLINE, and Iranian data bases. Then the meta-analysis was performed by comprehensive meta-analysis software (CMA. Results:    The meta-analysis showed that the prevalence of nontuberculous mycobacteria in the clinical specimens in Iran was 1.3%. In the studies that had sample size less than 300, and in studies conducted after 2004, the prevalence was higher. Also, the prevalence of nontuberculous mycobacteria was higher in the West of Iran. In this study, the most prevalent rapid-growing mycobacterium was Mycobacterium. fortuitum and  most prevalent slow-growing mycobacterium was M. simiae with the prevalence 44.2% and 14.3%, respectively.Conclusion:   M. simiae is the most prevalent nontuberculous mycobacteria in the clinical specimens in Iran. As this species of nontuberculous mycobacteria has similar clinical and radiological manifestations with tuberculosis, it is often treated as tuberculosis. Unfortunately, M. simiae is resistant against first-line anti-TB drugs resulting in treatment failure after using routine anti-TB medication. Therefore, there is an urgent need for application of new diagnostic strategy for identification of nontuberculous mycobacteria species.

The Use of Exogenous Melatonin in Delayed Sleep Phase Disorder: a Meta-analysis

NARCIS (Netherlands)

Geijlswijk, I.M. van; Korzilius, H.P.L.M.; Smits, M.G.

2010-01-01

Study Objectives: To perform a meta-analysis of the efficacy and safety of exogenous melatonin in advancing sleep-wake rhythm in patients with delayed sleep phase disorder. Design: Meta analysis of papers indexed for PubMed, Embase, and the abstracts of sleep and chronobiologic societies

Meta-analysis of the relationship between psychosocial indexes with mental health

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Ayaub Faizy

2015-09-01

Full Text Available Background: The expansion of studies that done in the demand of effective factors such as social factors on mental health provides the ground work for the combination of these studies. So, this meta-analysis was implemented to determine the summary effect size of the relationship between social indexes and mental health measures Material and Methods: The method used in this study is a Meta-Analysis. To achieve above aim used of quantitative findings from 46 studies, that computed 77 effect sizes from these. The studies that were used in this study collected from databases such as magiran, noormags, Scientific Information Database and proceeding articles that published in the Seminars of college student’s Mental Health. After reviewing the inclusion and exclusion criteria, the correlation effect sizes in selected studies were analyzed with the CMA2 software. In this study, were calculated both random and fixed models, that selected random model, according to the results of the heterogeneity analysis of the Q and I2 factors. Results: The results showed that the combinational effect size of the studies obtained 0.139, after eliminated 10 effect sizes. The combined effect size of studies was calculated low based on Cohen's criteria. Also, the results of heterogeneity analysis indicated that there are moderating variables in the studies. The evidence of this meta-analysis associated with prior theoretical and empirical foundations, indicates the relationship between social support and mental health. Conclusion: According to the results of this meta-analysis for successful mental health programs due to cultural and social issues will be necessary.

Multivariate meta-analysis: a robust approach based on the theory of U-statistic.

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Ma, Yan; Mazumdar, Madhu

2011-10-30

Meta-analysis is the methodology for combining findings from similar research studies asking the same question. When the question of interest involves multiple outcomes, multivariate meta-analysis is used to synthesize the outcomes simultaneously taking into account the correlation between the outcomes. Likelihood-based approaches, in particular restricted maximum likelihood (REML) method, are commonly utilized in this context. REML assumes a multivariate normal distribution for the random-effects model. This assumption is difficult to verify, especially for meta-analysis with small number of component studies. The use of REML also requires iterative estimation between parameters, needing moderately high computation time, especially when the dimension of outcomes is large. A multivariate method of moments (MMM) is available and is shown to perform equally well to REML. However, there is a lack of information on the performance of these two methods when the true data distribution is far from normality. In this paper, we propose a new nonparametric and non-iterative method for multivariate meta-analysis on the basis of the theory of U-statistic and compare the properties of these three procedures under both normal and skewed data through simulation studies. It is shown that the effect on estimates from REML because of non-normal data distribution is marginal and that the estimates from MMM and U-statistic-based approaches are very similar. Therefore, we conclude that for performing multivariate meta-analysis, the U-statistic estimation procedure is a viable alternative to REML and MMM. Easy implementation of all three methods are illustrated by their application to data from two published meta-analysis from the fields of hip fracture and periodontal disease. We discuss ideas for future research based on U-statistic for testing significance of between-study heterogeneity and for extending the work to meta-regression setting. Copyright © 2011 John Wiley & Sons, Ltd.

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

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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

Immunotherapy in advanced melanoma: a network meta-analysis.

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Pyo, Jung-Soo; Kang, Guhyun

2017-05-01

The aim of this study was to compare the effects of various immunotherapeutic agents and chemotherapy for unresected or metastatic melanomas. We performed a network meta-analysis using a Bayesian statistical model to compare objective response rate (ORR) of various immunotherapies from 12 randomized controlled studies. The estimated ORRs of immunotherapy and chemotherapy were 0.224 and 0.108, respectively. The ORRs of immunotherapy in untreated and pretreated patients were 0.279 and 0.176, respectively. In network meta-analysis, the odds ratios for ORR of nivolumab (1 mg/kg)/ipilmumab (3 mg/kg), pembrolizumab 10 mg/kg and nivolumab 3 mg/kg were 8.54, 5.39 and 4.35, respectively, compared with chemotherapy alone. Our data showed that various immunotherapies had higher ORRs rather than chemotherapy alone.

Relaxation training for anxiety: a ten-years systematic review with meta-analysis

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Manzoni, Gian Mauro; Pagnini, Francesco; Castelnuovo, Gianluca; Molinari, Enrico

2008-01-01

Background Relaxation training is a common treatment for anxiety problems. Lacking is a recent quantitative meta-analysis that enhances understanding of the variability and clinical significance of anxiety reduction outcomes after relaxation treatment. Methods All studies (1997–2007), both RCT, observational and without control group, evaluating the efficacy of relaxation training (Jacobson's progressive relaxation, autogenic training, applied relaxation and meditation) for anxiety problems and disorders were identified by comprehensive electronic searches with Pubmed, Psychinfo and Cochrane Registers, by checking references of relevant studies and of other reviews. Our primary outcome was anxiety measured with psychometric questionnaires. Meta-analysis was undertaken synthesizing the data from all trials, distinguishing within and between effect sizes. Results 27 studies qualified for the inclusion in the meta-analysis. As hypothesized, relaxation training showed a medium-large effect size in the treatment of anxiety. Cohen's d was .57 (95% CI: .52 to .68) in the within analysis and .51 (95% CI: .46 to .634) in the between group analysis. Efficacy was higher for meditation, among volunteers and for longer treatments. Implications and limitations are discussed. Conclusion The results show consistent and significant efficacy of relaxation training in reducing anxiety. This meta-analysis extends the existing literature through facilitation of a better understanding of the variability and clinical significance of anxiety improvement subsequent to relaxation training. PMID:18518981

Relaxation training for anxiety: a ten-years systematic review with meta-analysis

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Castelnuovo Gianluca

2008-06-01

Full Text Available Abstract Background Relaxation training is a common treatment for anxiety problems. Lacking is a recent quantitative meta-analysis that enhances understanding of the variability and clinical significance of anxiety reduction outcomes after relaxation treatment. Methods All studies (1997–2007, both RCT, observational and without control group, evaluating the efficacy of relaxation training (Jacobson's progressive relaxation, autogenic training, applied relaxation and meditation for anxiety problems and disorders were identified by comprehensive electronic searches with Pubmed, Psychinfo and Cochrane Registers, by checking references of relevant studies and of other reviews. Our primary outcome was anxiety measured with psychometric questionnaires. Meta-analysis was undertaken synthesizing the data from all trials, distinguishing within and between effect sizes. Results 27 studies qualified for the inclusion in the meta-analysis. As hypothesized, relaxation training showed a medium-large effect size in the treatment of anxiety. Cohen's d was .57 (95% CI: .52 to .68 in the within analysis and .51 (95% CI: .46 to .634 in the between group analysis. Efficacy was higher for meditation, among volunteers and for longer treatments. Implications and limitations are discussed. Conclusion The results show consistent and significant efficacy of relaxation training in reducing anxiety. This meta-analysis extends the existing literature through facilitation of a better understanding of the variability and clinical significance of anxiety improvement subsequent to relaxation training.

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

Associations between interleukin-1 gene polymorphisms and sepsis risk: a meta-analysis

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2014-01-01

Background Previous epidemiological studies have presented conflicting evidence regarding associations between interleukin-1 (IL-1) polymorphisms and sepsis susceptibility. We have performed a meta-analysis to evaluate possible associations between IL-1 polymorphisms and sepsis risk. Methods Eligible literature was retrieved from PubMed, Embase and Web of Knowledge databases until Jun 15, 2013. The pooled odds ratio (OR) and 95% confidence interval (CI) were calculated using random-effects model in the overall and subgroup analysis based on ethnicity, sepsis severity and quality score. Results Eighteen studies addressing five IL-1 polymorphisms were included in this meta-analysis. For IL-1A-889 (rs1800587) polymorphism, significant association was observed in overall comparison for allelic effect (OR = 1.47, 95% CI = 1.01-2.13, P = 0.04). There were no significant associations between either IL-1B-511 (rs16944) or IL-1B-31 (rs1143627) and sepsis susceptibility in overall or subgroup analyses. For IL-1B + 3594 (rs143634) polymorphism, genotype TT decreased sepsis risk in overall analysis (OR = 0.59, 95% CI = 0.36-0.97, P = 0.04), as well as in Caucasian (OR = 0.57, 95% CI = 0.34-0.95, P = 0.03) and sepsis (OR = 0.55, 95% CI = 0.31-0.97, P = 0.04) subgroup analysis. For IL-1RN VNTR polymorphism, significant association was observed in overall comparison for allelic effect (OR = 1.40, 95% CI = 1.01-1.95, P = 0.04). Furthermore, the effect sizes of IL-1RN VNTR on sepsis risk increased with disease severity (septic shock OR > severe sepsis OR > sepsis OR). Conclusions Our meta-analysis indicated that IL-1A-889, IL-1B + 3954 and IL-1RN VNTR might be associated with sepsis susceptibility. However, further studies with larger sample sizes and from homogenous populations would be necessary to validate these findings. PMID:24428862

Multivariate meta-analysis: modelling the heterogeneity mixing apples and oranges; dangerous or delicious?

NARCIS (Netherlands)

L.R. Arends (Lidia)

2006-01-01

textabstractMeta-analysis may be broadly defined as the quantitative review and synthesis of the results of related but independent studies. For the simple case where meta-analysis concerns only one outcome measure in each study, the statistical methods are well established now. However, in many

Meta-Analysis of Placental Transcriptome Data Identifies a Novel Molecular Pathway Related to Preeclampsia.

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van Uitert, Miranda; Moerland, Perry D; Enquobahrie, Daniel A; Laivuori, Hannele; van der Post, Joris A M; Ris-Stalpers, Carrie; Afink, Gijs B

2015-01-01

Studies using the placental transcriptome to identify key molecules relevant for preeclampsia are hampered by a relatively small sample size. In addition, they use a variety of bioinformatics and statistical methods, making comparison of findings challenging. To generate a more robust preeclampsia gene expression signature, we performed a meta-analysis on the original data of 11 placenta RNA microarray experiments, representing 139 normotensive and 116 preeclamptic pregnancies. Microarray data were pre-processed and analyzed using standardized bioinformatics and statistical procedures and the effect sizes were combined using an inverse-variance random-effects model. Interactions between genes in the resulting gene expression signature were identified by pathway analysis (Ingenuity Pathway Analysis, Gene Set Enrichment Analysis, Graphite) and protein-protein associations (STRING). This approach has resulted in a comprehensive list of differentially expressed genes that led to a 388-gene meta-signature of preeclamptic placenta. Pathway analysis highlights the involvement of the previously identified hypoxia/HIF1A pathway in the establishment of the preeclamptic gene expression profile, while analysis of protein interaction networks indicates CREBBP/EP300 as a novel element central to the preeclamptic placental transcriptome. In addition, there is an apparent high incidence of preeclampsia in women carrying a child with a mutation in CREBBP/EP300 (Rubinstein-Taybi Syndrome). The 388-gene preeclampsia meta-signature offers a vital starting point for further studies into the relevance of these genes (in particular CREBBP/EP300) and their concomitant pathways as biomarkers or functional molecules in preeclampsia. This will result in a better understanding of the molecular basis of this disease and opens up the opportunity to develop rational therapies targeting the placental dysfunction causal to preeclampsia.

Effectiveness of problem-based learning in Chinese pharmacy education: a meta-analysis.

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Zhou, Jiyin; Zhou, Shiwen; Huang, Chunji; Xu, Rufu; Zhang, Zuo; Zeng, Shengya; Qian, Guisheng

2016-01-19

This review provides a critical overview of problem-based learning (PBL) practices in Chinese pharmacy education. PBL has yet to be widely applied in pharmaceutical education in China. The results of those studies that have been conducted are published in Chinese and thus may not be easily accessible to international researchers. Therefore, this meta-analysis was carried out to review the effectiveness of PBL. Databases were searched for studies in accordance with the inclusion criteria. Two reviewers independently performed the study identification and data extraction. A meta-analysis was conducted using Revman 5.3 software. Sixteen randomized controlled trials were included. The meta-analysis revealed that PBL had a positive association with higher theoretical scores (SMD = 1.17, 95% CI [0.77, 11.57], P methods are superior to conventional teaching methods in improving students' learning interest, independent analysis skills, scope of knowledge, self-study, team spirit, and oral expression. This meta-analysis indicates that PBL pedagogy is superior to traditional lecture-based teaching in Chinese pharmacy education. PBL methods could be an optional, supplementary method of pharmaceutical teaching in China. However, Chinese pharmacy colleges and universities should revise PBL curricula according to their own needs, which would maximize the effectiveness of PBL.

Small studies are more heterogeneous than large ones: a meta-meta-analysis

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Hout, J. in't; Ioannidis, J.P.; Borm, G.F.; Goeman, J.J.

2015-01-01

OBJECTIVES: Between-study heterogeneity plays an important role in random-effects models for meta-analysis. Most clinical trials are small, and small trials are often associated with larger effect sizes. We empirically evaluated whether there is also a relationship between trial size and

Effect of Continuous Positive Airway Pressure on Adiponectin in Patients with Obstructive Sleep Apnea: A Meta-Analysis.

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Li-Da Chen

Full Text Available Obstructive sleep apnea (OSA has been suggested to be associated with low levels of adiponectin. Continuous positive airway pressure (CPAP is the gold standard treatment for OSA; however, previous studies assessing the effect of CPAP on adiponectin in patients with OSA yielded conflicting results. The present meta-analysis was performed to determine whether CPAP therapy could increase adiponectin levels.Two reviewers independently searched PubMed, Cochrane library, Embase and Web of Science before February 2015. Information on characteristics of subjects, study design and pre- and post-CPAP treatment of serum adiponectin was extracted for analysis. Standardized mean difference (SMD was used to analyze the summary estimates for CPAP therapy.Eleven studies involving 240 patients were included in this meta-analysis, including ten observational studies and one randomized controlled study. The meta-analysis showed that there was no change of adiponectin levels before and after CPAP treatment in OSA patients (SMD = 0.059, 95% confidence interval (CI = -0.250 to 0.368, z = 0.37, p = 0.710. Subgroup analyses indicated that the results were not affected by age, baseline body mass index, severity of OSA, CPAP therapy duration, sample size and racial differences.This meta-analysis suggested that CPAP therapy has no impact on adiponectin in OSA patients, without significant changes in body weight. Further large-scale, well-designed long-term interventional investigations are needed to clarify this issue.

Computer use and carpal tunnel syndrome: A meta-analysis.

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Shiri, Rahman; Falah-Hassani, Kobra

2015-02-15

Studies have reported contradictory results on the role of keyboard or mouse use in carpal tunnel syndrome (CTS). This meta-analysis aimed to assess whether computer use causes CTS. Literature searches were conducted in several databases until May 2014. Twelve studies qualified for a random-effects meta-analysis. Heterogeneity and publication bias were assessed. In a meta-analysis of six studies (N=4964) that compared computer workers with the general population or other occupational populations, computer/typewriter use (pooled odds ratio (OR)=0.72, 95% confidence interval (CI) 0.58-0.90), computer/typewriter use ≥1 vs. computer/typewriter use ≥4 vs. computer/typewriter use (pooled OR=1.34, 95% CI 1.08-1.65), mouse use (OR=1.93, 95% CI 1.43-2.61), frequent computer use (OR=1.89, 95% CI 1.15-3.09), frequent mouse use (OR=1.84, 95% CI 1.18-2.87) and with years of computer work (OR=1.92, 95% CI 1.17-3.17 for long vs. short). There was no evidence of publication bias for both types of studies. Studies that compared computer workers with the general population or several occupational groups did not control their estimates for occupational risk factors. Thus, office workers with no or little computer use are a more appropriate comparison group than the general population or several occupational groups. This meta-analysis suggests that excessive computer use, particularly mouse usage might be a minor occupational risk factor for CTS. Further prospective studies among office workers with objectively assessed keyboard and mouse use, and CTS symptoms or signs confirmed by a nerve conduction study are needed. Copyright © 2014 Elsevier B.V. All rights reserved.

Meta-Analysis of Comparing Personal and Environmental Factors Effective in Addiction Relapse (Iran, 2004 -2012

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s Safari

2014-12-01

Full Text Available Objective: This As a meta-analysis, this study aimed to integrate different studies and investigate the impact of individual and environmental factors on the reappearance of addiction in quitted people. Method: This study is a meta-analysis which uses Hunter and Schmidt approach. For this purpose, 28 out of 42 studies enjoying acceptable methodologies were selected, upon which the meta-analysis was conducted. A meta-analysis checklist was the research instrument. Using summary of the study results, the researcher manually calculated effect size and interpreted it based on the meta-analysis approach and Cohen’s table. Findings: Results revealed that the effect size of environmental factors on addiction relapse was 0.64 while it was obtained 0.41 for individual factors on addiction relapse. Conclusion: According to Cohen’s table, the effect sizes are evaluated as moderate and high for individual factors and environmental factors on addiction relapse, respectively.

Prognostic Value of microRNA-9 in Various Cancers: a Meta-analysis.

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Zhang, Yunyuan; Zhou, Jun; Sun, Meiling; Sun, Guirong; Cao, Yongxian; Zhang, Haiping; Tian, Runhua; Zhou, Lan; Duan, Liang; Chen, Xian; Lun, Limin

2017-07-01

Recently, there are more and more evidences from studies have revealed the association between microRNA-9 (miR-9) expression and outcome in multiple cancers, but inconsistent results have also been reported. It is necessary to rationalize a meta analysis of all available data to clarify the prognostic role of miR-9. Eligible studies were selected through multiple search strategies and the quality was assessed by MOOSE. Data was extracted from studies according to the key statistics index. All analyses were performed using STATA software. Twenty studies were selected in the meta-analysis to evaluate the prognostic role of miR-9 in multiple tumors. MiR-9 expression level was an independent prognostic biomarker for OS in tumor patients using multivariate and univariate analyses. High expression levels of miR-9 was demonstrated to associated with poor overall survival (OS) (HR = 2.23, 95 % CI: 1.56-3.17, P analysis showed that residence region (China and Japan), sample size, cancer type (solid or leukemia), follow-up months and analysis method (qPCR) did not alter the predictive value of miR-9 on OS in various cancers. Furthermore, no significant associations were detected for miR-9 expression and lymph node metastasis or distant metastasis. The present results suggest that promoted miR-9 expression is associated with poor OS in patients with general cancers.

Diagnostic significance of microRNAs as novel biomarkers for bladder cancer: a meta-analysis of ten articles.

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Shi, Hong-Bin; Yu, Jia-Xing; Yu, Jian-Xiu; Feng, Zheng; Zhang, Chao; Li, Guang-Yong; Zhao, Rui-Ning; Yang, Xiao-Bo

2017-08-03

Previous studies have revealed the importance of microRNAs' (miRNAs) function as biomarkers in diagnosing human bladder cancer (BC). However, the results are discordant. Consequently, the possibility of miRNAs to be BC biomarkers was summarized in this meta-analysis. In this study, the relevant articles were systematically searched from CBM, PubMed, EMBASE, and Chinese National Knowledge Infrastructure (CNKI). The bivariate model was used to calculate the pooled diagnostic parameters and summary receiver operator characteristic (SROC) curve in this meta-analysis, thereby estimating the whole predictive performance. STATA software was used during the whole analysis. Thirty-one studies from 10 articles, including 1556 cases and 1347 controls, were explored in this meta-analysis. In short, the pooled sensitivity, area under the SROC curve, specificity, positive likelihood ratio, diagnostic odds ratio, and negative likelihood ratio were 0.72 (95%CI 0.66-0.76), 0.80 (0.77-0.84), 0.76 (0.71-0.81), 3.0 (2.4-3.8), 8 (5.0-12.0), and 0.37 (0.30-0.46) respectively. Additionally, sub-group and meta-regression analyses revealed that there were significant differences between ethnicity, miRNA profiling, and specimen sub-groups. These results suggested that Asian population-based studies, multiple-miRNA profiling, and blood-based assays might yield a higher diagnostic accuracy than their counterparts. This meta-analysis demonstrated that miRNAs, particularly multiple miRNAs in the blood, might be novel, useful biomarkers with relatively high sensitivity and specificity and can be used for the diagnosis of BC. However, further prospective studies with more samples should be performed for further validation.

The influence of stereotype threat on immigrants: review and meta-analysis

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Appel, Markus; Weber, Silvana; Kronberger, Nicole

2015-01-01

In many regions around the world students with certain immigrant backgrounds underachieve in educational settings. This paper provides a review and meta-analysis on one potential source of the immigrant achievement gap: stereotype threat, a situational predicament that may prevent students to perform up to their full abilities. A meta-analysis of 19 experiments suggests an overall mean effect size of 0.63 (random effects model) in support of stereotype threat theory. The results are complemen...

Network meta-analysis: a technique to gather evidence from direct and indirect comparisons

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2017-01-01

Systematic reviews and pairwise meta-analyses of randomized controlled trials, at the intersection of clinical medicine, epidemiology and statistics, are positioned at the top of evidence-based practice hierarchy. These are important tools to base drugs approval, clinical protocols and guidelines formulation and for decision-making. However, this traditional technique only partially yield information that clinicians, patients and policy-makers need to make informed decisions, since it usually compares only two interventions at the time. In the market, regardless the clinical condition under evaluation, usually many interventions are available and few of them have been studied in head-to-head studies. This scenario precludes conclusions to be drawn from comparisons of all interventions profile (e.g. efficacy and safety). The recent development and introduction of a new technique – usually referred as network meta-analysis, indirect meta-analysis, multiple or mixed treatment comparisons – has allowed the estimation of metrics for all possible comparisons in the same model, simultaneously gathering direct and indirect evidence. Over the last years this statistical tool has matured as technique with models available for all types of raw data, producing different pooled effect measures, using both Frequentist and Bayesian frameworks, with different software packages. However, the conduction, report and interpretation of network meta-analysis still poses multiple challenges that should be carefully considered, especially because this technique inherits all assumptions from pairwise meta-analysis but with increased complexity. Thus, we aim to provide a basic explanation of network meta-analysis conduction, highlighting its risks and benefits for evidence-based practice, including information on statistical methods evolution, assumptions and steps for performing the analysis. PMID:28503228

Body checking and body avoidance in eating disorders: Systematic review and meta-analysis.

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Nikodijevic, Alexandra; Buck, Kimberly; Fuller-Tyszkiewicz, Matthew; de Paoli, Tara; Krug, Isabel

2018-05-01

This review sought to systematically review and quantify the evidence related to body checking and body avoidance in eating disorders (EDs) to gauge the size of effects, as well as examine potential differences between clinical and nonclinical populations, and between different ED subtypes. PsycINFO, PsycARTICLES, PsycEXTRA, Cochrane Library, and MEDLINE databases were searched for academic literature published until October 2017. A grey literature search was also conducted. Fifty-two studies were identified for the systematic review, of which 34 were eligible for meta-analysis. Only female samples were included in the meta-analysis. ED cases experienced significantly higher body checking (d = 1.26, p < .001) and body avoidance (d = 1.88, p < .001) overall relative to healthy controls, but neither behaviour varied by ED subtype. In nonclinical samples, body checking (r = .60) and body avoidance (r = .56) were significantly correlated with ED pathology (p < .001). These findings support transdiagnostic theoretical models and approaches to ED treatment and early intervention programmes. Copyright © 2018 John Wiley & Sons, Ltd and Eating Disorders Association.

Robotic thyroidectomy versus endoscopic thyroidectomy: a meta-analysis

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Lin Shuang

2012-11-01

Full Text Available Abstract Background To conduct a meta-analysis to determine the relative merits of robotic thyroidectomy (RT and endoscopic thyroidectomy (ET. Methods A literature search was performed to identify comparative studies reporting peri-operative outcomes for RT and ET. Pooled odds ratios (ORs and weighted mean differences (WMDs with 95% confidence interval (95% CI were calculated using either a fixed-effects or a random-effects model. Results Six studies matched the selection criteria, which reported on 2048 subjects, of whom 978 underwent RT and 1070 underwent ET. Comparing the outcomes of RT with ET, this meta-analysis indicated that RT was associated with more complications (WMD = 1.51, 95% CI 1.18 to 1.94 and greater amount of drainage fluid (WMD = 17.10, 95% CI 5.69 to 28.51. Meanwhile, operating time (WMD = 1.50, 95% CI −39.59 to 42.58, conversion (WMD = 0.63, 95% CI 0.07 to 6.17, post-operative hospital stay (WMD = −0.05; 95% CI −0.18 to 0.08, and the number of lymph nodes harvested (WMD = 0.62, 95% CI −0.29 to 1.53 were similar for both procedures. Conclusion The results of this meta-analysis indicated that RT is associated with an increased risk of complications and a greater amount of drainage fluid. Therefore, RT does not appear to have any advantage over ET. Further studies are required to confirm these results.

Depression and risk of fracture and bone loss: an updated meta-analysis of prospective studies.

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Wu, Q; Liu, B; Tonmoy, S

2018-03-12

This meta-analysis pooled results from 23 qualifying individual cohort studies and found that depression was significantly associated with an increased risk of fractures and bone loss. The association between depression and risk of fracture remains controversial. We conducted a comprehensive meta-analysis to examine the effect of depression on the risk of osteoporotic fractures and bone loss. We searched databases and reviewed citations in relevant articles for eligible cohort studies. Two investigators independently conducted study selection, appraisal, and data abstraction through the use of a standardized protocol. Random effect models were used for meta-analysis. Cochrane Q and I 2 statistics were used to assess heterogeneity. Funnel plots and rank correlation tests were used to evaluate publication bias. Twenty-three studies were included for meta-analysis. In studies that reported hazard ratio (HR) as the outcome (nine studies [n = 309,862]), depression was associated with 26% increase in fracture risk (HR = 1.26, 95% CI, 1.10-1.43, p meta-analysis having modified inclusion criteria and in different subgroup analyses as well. Significant heterogeneity was observed in the meta-analysis; however, no significant publication bias was detected. Depression is associated with a significant increased risk in fracture and bone loss. Effective prevention may decrease such risk.

Prognostic value of C-reactive protein levels in patients with bone neoplasms: A meta-analysis.

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Li, Wenyi; Luo, Xujun; Liu, Zhongyue; Chen, Yanqiao; Li, Zhihong

2018-01-01

The aim of this study was to conduct a meta-analysis of retrospective studies that investigated the association of preoperative C-reactive protein (CRP) levels with the overall survival (OS) of patients with bone neoplasms. A detailed literature search was performed in the Cochrane Library, Web of Science, Embase and PubMed databases up to August 28, 2017, for related research publications written in English. We extracted the data from these studies and combined the hazard ratios (HR) and 95% confidence intervals (CIs) to assess the correlation between CRP levels and OS in patients with bone neoplasms. Five studies with a total of 816 participants from several countries were enrolled in this current meta-analysis. In a pooled analysis of all the publications, increased serum CRP levels had an adverse prognostic effect on the overall survival of patients with bone neoplasms. However, the combined data showed no significant relationship between the level of CRP and OS in Asian patients (HR = 1.73; 95% CI: 0.86-3.49; P = 0.125). Similar trends were observed in patients with bone neoplasms when stratified by ethnicity, histology, metastasis and study sample size. The results of this meta-analysis suggest that increased CRP expression indicates a poorer prognosis in patients with bone neoplasms. More prospective studies are needed to confirm the prognostic significance of CRP levels in patients with bone neoplasms.

Body mass index and risk of BPH: a meta-analysis.

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Wang, S; Mao, Q; Lin, Y; Wu, J; Wang, X; Zheng, X; Xie, L

2012-09-01

Epidemiological studies have reported conflicting results relating obesity to BPH. A meta-analysis of cohort and case-control studies was conducted to pool the risk estimates of the association between obesity and BPH. Eligible studies were retrieved by both computer searches and review of references. We analyzed abstracted data with random effects models to obtain the summary risk estimates. Dose-response meta-analysis was performed for studies reporting categorical risk estimates for a series of exposure levels. A total of 19 studies met the inclusion criteria of the meta-analysis. Positive association with body mass index (BMI) was observed in BPH and lower urinary tract symptoms (LUTS) combined group (odds ratio=1.27, 95% confidence intervals 1.05-1.53). In subgroup analysis, BMI exhibited a positive dose-response relationship with BPH/LUTS in population-based case-control studies and a marginal positive association was observed between risk of BPH and increased BMI. However, no association between BPH/LUTS and BMI was observed in other subgroups stratified by study design, geographical region or primary outcome. The overall current literatures suggested that BMI was associated with increased risk of BPH. Further efforts should be made to confirm these findings and clarify the underlying biological mechanisms.

The Effectiveness of Self-Regulated Learning Scaffolds on Academic Performance in Computer-Based Learning Environments: A Meta-Analysis

Science.gov (United States)

Zheng, Lanqin

2016-01-01

This meta-analysis examined research on the effects of self-regulated learning scaffolds on academic performance in computer-based learning environments from 2004 to 2015. A total of 29 articles met inclusion criteria and were included in the final analysis with a total sample size of 2,648 students. Moderator analyses were performed using a…

Systematic review and meta-analysis

DEFF Research Database (Denmark)

Lo, B; Prosberg, M V; Gluud, L L

2018-01-01

BACKGROUND: The Inflammatory Bowel Disease Disability Index (IBD-DI) has recently been developed for patients with Crohn's disease (CD) and ulcerative colitis (UC). AIM: To assess the severity of disability and associated factors using the IBD-DI, and review the validity of the IBD-DI as a tool. ...... review and meta-analysis found a significant association between disease activity, treatment received and disability; although significant heterogeneity was found. The IBD-DI is reliable and valid, but further studies are needed to measure its interpretability....

Association between depression and periodontitis: a systematic review and meta-analysis.

Science.gov (United States)

Araújo, Milena Moreira; Martins, Carolina Castro; Costa, Lidiane Cristina Machado; Cota, Luís Otávio Miranda; Faria, Rodrigo Lamounier Araújo Melo; Cunha, Fabiano Araújo; Costa, Fernando Oliveira

2016-03-01

The aim of this systematic review and meta-analysis was to assess the scientific evidence on the association between depression and periodontitis. An electronic search was conducted in three databases until October 2015 (PROSPERO-CRD42014006451). Hand searches and grey literature were also included. Search retrieved 423 potentially studies. Two independent reviewers selected the studies, extracted data and assessed risk bias through a modified version of Newcastle-Ottawa scale. Meta-analysis was performed for the presence/absence of periodontitis (dichotomic). Summary effect measures and odds ratio (OR) 95% CI were calculated. After selecting the studies, 15 were included in the systematic review (eight cross-sectional, six case-control and one cohort study). Six studies reported that depression was associated with periodontitis, whereas nine studies did not. The majority of studies had low risk of bias by methodological quality assessment. Meta-analysis of seven cross-sectional studies showed no significant association between depression and periodontitis (OR = 1.03, 95% CI = 0.75-1.41). Findings from the present systematic review showed a great heterogeneity among the studies and the summary effect measure of the meta-analysis cannot affirm an association between depression and periodontitis. Future studies with different designs in distinct populations should be conducted to investigate this association. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Meta-analysis of the serotonin transporter promoter variant (5-HTTLPR) in relation to adverse environment and antisocial behavior.

Science.gov (United States)

Tielbeek, Jorim J; Karlsson Linnér, Richard; Beers, Koko; Posthuma, Danielle; Popma, Arne; Polderman, Tinca J C

2016-07-01

Several studies have suggested an association between antisocial, aggressive, and delinquent behavior and the short variant of the serotonin transporter gene polymorphism (5-HTTLPR). Yet, genome wide and candidate gene studies in humans have not convincingly shown an association between these behaviors and 5-HTTLPR. Moreover, individual studies examining the effect of 5-HTTLPR in the presence or absence of adverse environmental factors revealed inconsistent results. We therefore performed a meta-analysis to test for the robustness of the potential interaction effect of the "long-short" variant of the 5-HTTLPR genotype and environmental adversities, on antisocial behavior. Eight studies, comprising of 12 reasonably independent samples, totaling 7,680 subjects with an effective sample size of 6,724, were included in the meta-analysis. Although our extensive meta-analysis resulted in a significant interaction effect between the 5-HTTLPR genotype and environmental adversities on antisocial behavior, the methodological constraints of the included studies hampered a confident interpretation of our results, and firm conclusions regarding the direction of effect. Future studies that aim to examine biosocial mechanisms that influence the etiology of antisocial behavior should make use of larger samples, extend to genome-wide genetic risk scores and properly control for covariate interaction terms, ensuring valid and well-powered research designs. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Bipolar disorder prevalence: a systematic review and meta-analysis of the literature

Directory of Open Access Journals (Sweden)

Adauto S. Clemente

2015-06-01

Full Text Available Objective:Bipolar disorder (BD is common in clinical psychiatric practice, and several studies have estimated its prevalence to range from 0.5 to 5% in community-based samples. However, no systematic review and meta-analysis of the prevalence of BD type 1 and type 2 has been published in the literature. We carried out a systematic review and meta-analysis of the lifetime and 1-year prevalence of BD type 1 and type 2 and assessed whether the prevalence of BD changed according to the diagnostic criteria adopted (DSM-III, DSM-III-R vs. DSM-IV.Methods:We searched MEDLINE, Scopus, Web of Science, PsycINFO, and the reference lists of identified studies. The analyses included 25 population- or community-based studies and 276,221 participants.Results:The pooled lifetime prevalence of BD type 1 was 1.06% (95% confidence interval [95%CI] 0.81-1.31 and that of BD type 2 was 1.57% (95%CI 1.15-1.99. The pooled 1-year prevalence was 0.71% (95%CI 0.56-0.86 for BD type 1 and 0.50% (95%CI 0.35-0.64 for BD type 2. Subgroup analysis showed a significantly higher lifetime prevalence of BD type 1 according to the DSM-IV criteria compared to the DSM-III and DSM-IIIR criteria (p < 0.001.Conclusion:This meta-analysis confirms that estimates of BD type 1 and type 2 prevalence are low in the general population. The increase in prevalence from DSM-III and DSM-III-R to DSM-IV may reflect different factors, such as minor changes in diagnostic operationalization, use of different assessment instruments, or even a genuine increase in the prevalence of BD.

Meta-analysis of transcutaneous electrical nerve stimulation for relief of spinal pain.

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Resende, L; Merriwether, E; Rampazo, É P; Dailey, D; Embree, J; Deberg, J; Liebano, R E; Sluka, K A

2018-04-01

We conducted a systematic review and meta-analysis analysing the existing data on transcutaneous electrical nerve stimulation (TENS) or interferential current (IFC) for chronic low back pain (CLBP) and/or neck pain (CNP) taking into account intensity and timing of stimulation, examining pain, function and disability. Seven electronic databases were searched for TENS or IFC treatment in non-specific CLBP or CNP. Four reviewers independently selected randomized controlled trials (RCTs) of TENS or IFC intervention in adult individuals with non-specific CLBP or CNP. Primary outcomes were for self-reported pain intensity and back-specific disability. Two reviewers performed quality assessment, and two reviewers extracted data using a standardized form. Nine RCTs were selected (eight CLBP; one CNP), and seven studies with complete data sets were included for meta-analysis (655 participants). For CLBP, meta-analysis shows TENS/IFC intervention, independent of time of assessment, was significantly different from placebo/control (p TENS/IFC intervention was better than placebo/control, during therapy (p = 0.02), but not immediately after therapy (p = 0.08), or 1-3 months after therapy (p = 0.99). Analysis for adequate stimulation parameters was not significantly different, and there was no effect on disability. This systematic review provides inconclusive evidence of TENS benefits in low back pain patients because the quality of the studies was low, and adequate parameters and timing of assessment were not uniformly used or reported. Without additional high-quality clinical trials using sufficient sample sizes and adequate parameters and outcome assessments, the outcomes of this review are likely to remain unchanged. These data highlight the need for additional high-quality RCTs to examine the effects of TENS in CLBP. Trials should consider intensity of stimulation, timing of outcome assessment and assessment of pain, disability and function. © 2017 European Pain

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.

Music-Induced Analgesia in Chronic Pain Conditions: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Garza-Villarreal, Eduardo A; Pando, Victor; Vuust, Peter; Parsons, Christine

2017-11-01

Music is increasingly used as an adjuvant for the management of chronic pain (CP), as it is non-invasive, inexpensive, and patients usually report positive experiences with it. However, little is known about its clinical efficacy in chronic pain patients. We aimed to determine the effect of music as an adjuvant for chronic pain, as well as to identify characteristics of music interventions associated with positive clinical outcomes. In this systematic review and meta-analysis, we investigated randomized controlled trials (RCTs) of adult patients that reported any type of music intervention for chronic pain, chosen by the researcher or patient, lasting for any duration. Searches were performed using PsycINFO, Scopus, and PubMed for RCTs published until the end of May 2016. The primary outcome was reduction in self-reported pain using a standardized pain measurement instrument, reported post-intervention. The secondary outcomes were: quality of life measures, depression, anxiety, and related measures. The study was pre-registered with PROSPERO (CRD42016039837), and the meta-analysis was performed using RevMan 5.3 (The Nordic Cochrane Centre for The Cochrane Collaboration, Copenhagen, Denmark). We identified 768 titles and abstracts, and we included 14 RTCs that fulfilled our criteria. The sample size of the studies varied between 25 and 200 patients. We found that music reduced self-reported chronic pain and depressive symptoms. We also found that music had a greater effect when the patient chose the music, compared to when the researcher chose it. The sample size of RCTs was small and sometimes with different outcome measures. There was high heterogeneity associated with pooled estimates. Our analysis suggests that music may be beneficial as an adjuvant for chronic pain patients, as it reduces self-reported pain and its common comorbidities. Importantly, the analgesic effect of music appears higher with self-chosen over researcher-chosen music. Pain, music

Internal fixation of mandibular angle fractures: a meta-analysis.

Science.gov (United States)

Regev, Eran; Shiff, Jacob S; Kiss, Alex; Fialkov, Jeffrey A

2010-06-01

The degree of rigidity of internal fixation required for the treatment of mandibular angle fractures has long been at the center of debate in the literature. A statistical comparison between rigid fixation and monocortical fixation has been difficult because of multiple terms, definitions, and technical variations. The purpose of this study was to use the meta-analysis tool to combine information from multiple studies and to compare complication rates for different fixation methods. An English language literature search was conducted for articles on mandibular angle fractures. Information was collected on four variables of interest: compression/noncompression technique, monocortical/bicortical screws, number of plates, and location of plates. Five outcome rates were analyzed: infection, reoperation, hardware removal, malunion, and nonunion. Meta-analyses were run using Comprehensive Meta Analysis, version 2.2.03. Twenty-four studies with relevant data on the variables and outcomes of interest met the inclusion criteria. Significantly higher rates of infection, reoperation, and hardware removal were found for compression compared with noncompression, two plates compared with one plate, and for plates located on both the inferior and superior borders as compared with superior or inferior only. There were also significantly higher infection rates for bicortical screws compared with monocortical screws and higher malunion rates for compression compared with noncompression plating techniques. The results of this meta-analysis found lower complication rates with the use of noncompression, monocortical, and single-plate fixation, supporting the trend toward a single, superiorly placed, monocortical miniplate for fixation of mandibular angle fractures.

A Meta-Analysis of the Relations among Training Criteria

National Research Council Canada - National Science Library

Alliger, George

1998-01-01

.... Meta-analysis results among criteria using this framework include the finding of substantial reliabilities across training criteria and reasonable convergence among subdivisions of criteria within a larger level...

An Introduction to MAMA (Meta-Analysis of MicroArray data) System.

Science.gov (United States)

Zhang, Zhe; Fenstermacher, David

2005-01-01

Analyzing microarray data across multiple experiments has been proven advantageous. To support this kind of analysis, we are developing a software system called MAMA (Meta-Analysis of MicroArray data). MAMA utilizes a client-server architecture with a relational database on the server-side for the storage of microarray datasets collected from various resources. The client-side is an application running on the end user's computer that allows the user to manipulate microarray data and analytical results locally. MAMA implementation will integrate several analytical methods, including meta-analysis within an open-source framework offering other developers the flexibility to plug in additional statistical algorithms.

A Meta-Analysis of Advance-Organizer Studies.

Science.gov (United States)

Stone, Carol Leth

Long term studies of advance organizers (AO) were analyzed with Glass's meta-analysis technique. AO's were defined as bridges from reader's previous knowledge to what is to be learned. The results were compared with predictions from Ausubel's model of assimilative learning. The results of the study indicated that advance organizers were associated…

The prevalence of depressive symptoms in frontotemporal dementia: a meta-analysis.

Science.gov (United States)

Chakrabarty, Trisha; Sepehry, Amir A; Jacova, Claudia; Hsiung, Ging-Yuek Robin

2015-01-01

Depression is common in Alzheimer's and vascular dementia and is associated with poorer outcomes; however, less is known about the impact of depression on frontotemporal dementia (FTD). Here, we conducted a meta-analysis of diagnostic methods and the prevalence of depressive symptoms in FTD. PubMed, EMBASE and PsychINFO were queried for 'depression' and/or 'depressive mood' in behavioral- and language-variant FTD. The prevalence and diagnosis of depressive symptoms were extracted from relevant studies and the results pooled using a random-effects model. We included 29 studies in this meta-analysis, with sample sizes ranging from 3 to 73 (n = 870). The omnibus estimated event rate of depressed mood was 0.334 (33%; 95% CI: 0.268-0.407). Symptoms were most commonly assessed via standardized neuropsychiatric rating scales, with other methods including subjective caregiver reports and chart reviews. The study results were heterogeneous due to the variability in diagnostic methods. Depressive symptoms similar to those in other dementias are commonly detected in FTD. However, the diagnostic methods are heterogeneous, and symptoms of depression often overlap with manifestations of FTD. Having a standardized diagnostic approach to depression in FTD will greatly facilitate future research in this area.

Inference for binomial probability based on dependent Bernoulli random variables with applications to meta-analysis and group level studies.

Science.gov (United States)

Bakbergenuly, Ilyas; Kulinskaya, Elena; Morgenthaler, Stephan

2016-07-01

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group-level studies or in meta-analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arising from standard log-odds and arcsine transformations of the estimated probability p̂, both for single-group studies and in combining results from several groups or studies in meta-analysis. Our simulations confirm that these biases are linear in ρ, for small values of ρ, the intracluster correlation coefficient. These biases do not depend on the sample sizes or the number of studies K in a meta-analysis and result in abysmal coverage of the combined effect for large K. We also propose bias-correction for the arcsine transformation. Our simulations demonstrate that this bias-correction works well for small values of the intraclass correlation. The methods are applied to two examples of meta-analyses of prevalence. © 2016 The Authors. Biometrical Journal Published by Wiley-VCH Verlag GmbH & Co. KGaA.

Meta-Analysis: Treatment of Attention-Deficit/Hyperactivity Disorder in Children with Comorbod Tic Disorders

Science.gov (United States)

Bloch, Michael H.; Panza, Kaitlyn E.; Landeros-Weisenberger, Angeli; Leckman, James F.

2009-01-01

Methylphenidate appears to provide the greatest and most immediate improvement of the symptoms of attention deficit hyperactivity disorder and does not appear to worsen tic symptoms based on a meta-analysis study. The meta-analysis included nine studies with 477 subjects.

[Meta-analysis of pathological gambling 1997-2007].

Science.gov (United States)

Muñoz-Molina, Yaromir

2008-01-01

Determining the prevalence of pathological gambling related to variables such as age and sex; furthermore, identifying the most current tools used for measuring it and the kind of gaming associated with this type of obsessive behavior. A meta-analysis of studies concerning pathological gambling published between 1997 and 2007 was carried out. Inclusion criteria for papers consisted of having a probabilistic sample, indicating the tool used for measuring it and presenting the prevalence rate. It was observed that pathological gambling affects men more than women; furthermore, there are differences amongst adults and adolescents related to this type of behaviour, the latter group having the higher prevalence rate. Video lottery terminals are the most frequently occurring type of game associated with pathological gambling. Pathological gambling deserves more attention by public health managers. Prevalence studies help to understand it better.

Golgi protein 73 as a biomarker for hepatocellular carcinoma: A diagnostic meta-analysis.

Science.gov (United States)

Yang, Jing; Li, Jingjing; Dai, Weiqi; Wang, Fan; Shen, Miao; Chen, Kan; Cheng, Ping; Zhang, Yan; Wang, Chengfen; Zhu, Rong; Zhang, Huawei; Zheng, Yuanyuan; Wang, Junshan; Xia, Yujing; Lu, Jie; Zhou, Yingqun; Guo, Chuanyong

2015-04-01

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and the third leading cause of cancer-related mortality worldwide. Conflicting results have been reported regarding the use of serum Golgi protein 73 (GP73) as a promising serum marker for the diagnosis of HCC; therefore, the aim of the present study was to provide a systematic review of the diagnostic performance of GP73 for HCC. Following a systematic review of the relevant studies, a number of indices associated with the accuracy of the diagnostic performance of GP73, including the sensitivity and specificity, were pooled using Meta Disc 1.4 software. Data were presented as forest plots, and summary receiver operating characteristic (SROC) curve analysis was used to summarize the overall test performance. Eleven studies were included in this meta-analysis. The summary estimates for serum GP73 in diagnosing HCC were as follows: Sensitivity, 77% [95% confidence interval (CI), 75-79%]; specificity, 91% (95% CI, 90-92%); positive likelihood ratio, 4.34 (95% CI, 2.19-8.59); negative likelihood ratio, 0.30 (95% CI, 0.26-0.36) and diagnostic odds ratio, 15.78 (95% CI, 6.95-35.83). The area under the SROC curve was 0.8638, and the Q index was 0.7944. Significant heterogeneity was found. This meta-analysis indicates a moderate diagnostic value of GP73 in HCC; however, further studies with rigorous design, large sample size and multiregional cooperation are required.

Meta-analysis of genetic polymorphisms in xenobiotic metabolizing ...

Indian Academy of Sciences (India)

TAJAMUL HUSSAIN

2018-06-12

Jun 12, 2018 ... ity in COMT protein, thus impairing conversion of cate- chol oestrogens ... nale of the current meta-analysis is to address the ambi- guity in the .... disease association across the globe with this polymor- ..... Health Perspect. 117 ...

Impact of Mobile Assisted Language Learning (MALL on EFL: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Imtiaz Hassan Taj

2016-04-01

Full Text Available Mobile Assisted Language Learning (MALL has emerged as a potential tool in the instruction of English as a foreign language (EFL. Meta-analysis of 13 studies published between year 2008 and 2015 was conducted. Four point criteria for the selection of studies for analysis is based on the year of publication, quasi-experimental design, pretest and posttest method and finally use of mobile device for intervention. Findings of the analysis suggest that MALL has fostered the EFL instruction. Overall effect size was (d = 0.8 which is considered a large effect size. Keywords: MALL, technology assisted language learning, EFL, vocabulary acquisition, vocabulary instruction, meta-analysis

Effect of Sling Exercise Training on Balance in Patients with Stroke: A Meta-Analysis.

Science.gov (United States)

Chen, Lianghua; Chen, Junqi; Peng, Qiyuan; Chen, Jingjie; Zou, Yucong; Liu, Gang

2016-01-01

This study aims to evaluate the effect of sling exercise training (SET) on balance in patients with stroke. PubMed, Cochrane Library, Ovid LWW, CBM, CNKI, WanFang, and VIP databases were searched for randomized controlled trials of the effect of SET on balance in patients with stroke. The study design and participants were subjected to metrological analysis. Berg balance Scale (BBS), Barthel index score (BI), and Fugl-Meyer Assessment (FMA) were used as independent parameters for evaluating balance function, activities of daily living(ADL) and motor function after stroke respectively, and were subjected to meta-analysis by RevMan5.3 software. Nine studies with 460 participants were analyzed. Results of meta-analysis showed that the SET treatment combined with conventional rehabilitation was superior to conventional rehabilitation treatments, with increased degrees of BBS (WMD = 3.81, 95% CI [0.15, 7.48], P = 0.04), BI (WMD = 12.98, 95% CI [8.39, 17.56], P risk of bias. Therefore, more multi-center and large-sampled randomized controlled trials are needed to confirm its clinical applications.

Contact With Mental Health Services Prior to Suicide: A Systematic Review and Meta-Analysis.

Science.gov (United States)

Walby, Fredrik A; Myhre, Martin Øverlien; Kildahl, Anine Therese

2018-04-16

Access to mental health care is regarded as a central suicide prevention strategy. This is the first systematic review and meta-analysis of the prevalence of contact with mental health services preceding suicide. A systematic search for articles reporting prevalence of contact with mental health services before suicide was conducted in MEDLINE and PsycINFO, restricted to studies published from January 1, 2000, to January 12, 2017. A random-effects meta-analysis with double arcsine transformations was conducted, with meta-regression used to explore heterogeneity. Thirty-five studies were included in the systematic review, and 20 were included in the meta-analysis. Among suicide decedents in the population, 3.7% (95% confidence interval [CI]=2.6%-4.8%) were inpatients at the time of death. In the year before death, 18.3% (CI=14.6%-22.4%) of suicide decedents had contact with inpatient mental health services, 26.1% (CI=16.5%-37.0%) had contact with outpatient mental health services, and 25.7% (CI=22.7%-28.9%) had contact with inpatient or outpatient mental health services. Meta-regression showed that women had significantly higher levels of contact compared with men and that the prevalence of contact with inpatient or outpatient services increased according to the sample year. Contact with services prior to suicide was found to be common and contact with inpatient or outpatient mental health services before suicide seems to be increasing. However, the reviewed studies were mainly conducted in Western European and North American countries, and most studies focused on psychiatric hospitalization, which resulted in limited data on contact with outpatient services. Better monitoring and data on suicides that occur during and after treatment seem warranted.

Genome-wide association study meta-analysis of European and Asian-ancestry samples identifies three novel loci associated with bipolar disorder.

Science.gov (United States)

Chen, D T; Jiang, X; Akula, N; Shugart, Y Y; Wendland, J R; Steele, C J M; Kassem, L; Park, J-H; Chatterjee, N; Jamain, S; Cheng, A; Leboyer, M; Muglia, P; Schulze, T G; Cichon, S; Nöthen, M M; Rietschel, M; McMahon, F J; Farmer, A; McGuffin, P; Craig, I; Lewis, C; Hosang, G; Cohen-Woods, S; Vincent, J B; Kennedy, J L; Strauss, J

2013-02-01

Meta-analyses of bipolar disorder (BD) genome-wide association studies (GWAS) have identified several genome-wide significant signals in European-ancestry samples, but so far account for little of the inherited risk. We performed a meta-analysis of ∼750,000 high-quality genetic markers on a combined sample of ∼14,000 subjects of European and Asian-ancestry (phase I). The most significant findings were further tested in an extended sample of ∼17,700 cases and controls (phase II). The results suggest novel association findings near the genes TRANK1 (LBA1), LMAN2L and PTGFR. In phase I, the most significant single nucleotide polymorphism (SNP), rs9834970 near TRANK1, was significant at the P=2.4 × 10(-11) level, with no heterogeneity. Supportive evidence for prior association findings near ANK3 and a locus on chromosome 3p21.1 was also observed. The phase II results were similar, although the heterogeneity test became significant for several SNPs. On the basis of these results and other established risk loci, we used the method developed by Park et al. to estimate the number, and the effect size distribution, of BD risk loci that could still be found by GWAS methods. We estimate that >63,000 case-control samples would be needed to identify the ∼105 BD risk loci discoverable by GWAS, and that these will together explain <6% of the inherited risk. These results support previous GWAS findings and identify three new candidate genes for BD. Further studies are needed to replicate these findings and may potentially lead to identification of functional variants. Sample size will remain a limiting factor in the discovery of common alleles associated with BD.

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.

Meta-Analysis of Parent-Mediated Interventions for Young Children with Autism Spectrum Disorder

Science.gov (United States)

Nevill, Rose E.; Lecavalier, Luc; Stratis, Elizabeth A.

2018-01-01

A number of studies of parent-mediated interventions in autism spectrum disorder have been published in the last 15 years. We reviewed 19 randomized clinical trials of parent-mediated interventions for children with autism spectrum disorder between the ages of 1 and 6 years and conducted a meta-analysis on their efficacy. Meta-analysis outcomes…

A systematic review and meta-analysis of the proportion of dogs surrendered for dog-related and owner-related reasons.

Science.gov (United States)

Lambert, Kim; Coe, Jason; Niel, Lee; Dewey, Cate; Sargeant, Jan M

2015-01-01

Companion-animal relinquishment is a worldwide phenomenon that leaves companion animals homeless. Knowing why humans make the decision to end their relationship with a companion-animal can help in our understanding of this complex societal issue and can help to develop preventive strategies. A systematic review and meta-analysis was conducted to summarize reasons why dogs are surrendered, and determine if certain study characteristics were associated with the reported proportions of reasons for surrender. Articles investigating one or more reasons for dog surrender were selected from the references of a published scoping review. Two reviewers assessed the titles and abstracts of these articles, identifying 39 relevant articles. From these, 21 articles were further excluded because of ineligible study design, insufficient data available for calculating a proportion, or no data available for dogs. Data were extracted from 18 articles and meta-analysis was conducted on articles investigating reasons for dog surrender to a shelter (n=9) or dog surrender for euthanasia (n=5). Three studies were excluded from meta-analysis because they were duplicate populations. Other reasons for excluding studies from meta-analysis were, (1) the study only investigated reasons for dog re-relinquishment (n=2) and (2) the study sample size was dog surrender to a shelter and dog surrender for euthanasia. Results of meta-analysis found owner health/illness as a reason for dog surrender to a shelter had an overall estimate of 4.6% (95% CI: 4.1%, 5.2%). For all other identified reasons for surrender there was significant variation in methodology among studies preventing further meta-analysis. Univariable meta-regression was conducted to explore sources of variation among these studies. Country was identified as a significant source of variation (pdog surrender for euthanasia. The overall estimate for studies from Australia was 10% (95% CI: 8.0%, 12.0%; I(2)=15.5%), compared to 16% (95% CI

Meta-analysis and systematic review of studies on the effectiveness of HIV stigma reduction programs.

Science.gov (United States)

Mak, Winnie W S; Mo, Phoenix K H; Ma, Gloria Y K; Lam, Maggie Y Y

2017-09-01

The present study conducted a meta-analysis and systematic review on studies evaluating the effectiveness of stigma reduction programs in improving knowledge and reducing negative attitudes towards people living with HIV (PLHIV). Meta-analysis (k = 42 studies) found significant and small effect sizes in the improvement of the participants' knowledge of HIV/AIDS from interventions with (Cohen's d = 0.48, 95% CI [0.30, 0.66]) and without control groups (Cohen's d = 0.42, 95% CI [0.28, 0.57]). Significant and small effect sizes were found in the improvement of the participants' attitudes toward PLHIV from interventions with (Cohen's d = 0.39, 95% CI [0.23, 0.55]) and without control groups (Cohen's d = 0.25, 95% CI [0.11, 0.39]). Significant and small effect sizes were sustained at the follow-up assessments. Subgroup analysis showed that number of intervention sessions, intervention settings, and sample type significantly moderated the effect sizes in the meta-analysis. Findings from the systematic review of 35 studies indicated that most of the included studies showed positive results in reducing negative attitudes toward PLHIV and improving HIV-related knowledge. Most of the included studies tended to have low methodological quality. The present meta-analysis and systematic review indicated that the studies generally found small improvement in HIV-related knowledge and reduction in negative attitudes towards PLHIV among the stigma reduction programs being evaluated. High-quality stigma reduction programs with multidimensional stigma indicators and psychometrically sound outcome measures are highly warranted. Copyright © 2017 Elsevier Ltd. All rights reserved.

Meta-analysis of landscape conservation plan evaluations

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Michaela Foster; M. Nils Peterson; Frederick Cubbage; Gerard McMahon

2016-01-01

The number of studies evaluating the quality and content of many types of plans have grown in recent decades. Natural resource conservation plans have been included in some of these plan evaluation studies; however, no meta-analysis of natural resource planning literature has been conducted. This focus is needed because natural resource conservation planning differs...

Tutoring Adolescents in Literacy: A Meta-Analysis

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Jun, Seung Won; Ramirez, Gloria; Cumming, Alister

2010-01-01

What does research reveal about tutoring adolescents in literacy? We conducted a meta-analysis, identifying 152 published studies, of which 12 met rigorous inclusion criteria. We analyzed the 12 studies for the effects of tutoring according to the type, focus, and amount of tutoring; the number, age, and language background of students; and the…

A Meta-Analysis of Massage Therapy Research

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Moyer, Christopher A.; Rounds, James; Hannum, James W.

2004-01-01

Massage therapy (MT) is an ancient form of treatment that is now gaining popularity as part of the complementary and alternative medical therapy movement. A meta-analysis was conducted of studies that used random assignment to test the effectiveness of MT. Mean effect sizes were calculated from 37 studies for 9 dependent variables. Single…

Meta-Analysis of Placental Transcriptome Data Identifies a Novel Molecular Pathway Related to Preeclampsia.

Directory of Open Access Journals (Sweden)

Miranda van Uitert

Full Text Available Studies using the placental transcriptome to identify key molecules relevant for preeclampsia are hampered by a relatively small sample size. In addition, they use a variety of bioinformatics and statistical methods, making comparison of findings challenging. To generate a more robust preeclampsia gene expression signature, we performed a meta-analysis on the original data of 11 placenta RNA microarray experiments, representing 139 normotensive and 116 preeclamptic pregnancies. Microarray data were pre-processed and analyzed using standardized bioinformatics and statistical procedures and the effect sizes were combined using an inverse-variance random-effects model. Interactions between genes in the resulting gene expression signature were identified by pathway analysis (Ingenuity Pathway Analysis, Gene Set Enrichment Analysis, Graphite and protein-protein associations (STRING. This approach has resulted in a comprehensive list of differentially expressed genes that led to a 388-gene meta-signature of preeclamptic placenta. Pathway analysis highlights the involvement of the previously identified hypoxia/HIF1A pathway in the establishment of the preeclamptic gene expression profile, while analysis of protein interaction networks indicates CREBBP/EP300 as a novel element central to the preeclamptic placental transcriptome. In addition, there is an apparent high incidence of preeclampsia in women carrying a child with a mutation in CREBBP/EP300 (Rubinstein-Taybi Syndrome. The 388-gene preeclampsia meta-signature offers a vital starting point for further studies into the relevance of these genes (in particular CREBBP/EP300 and their concomitant pathways as biomarkers or functional molecules in preeclampsia. This will result in a better understanding of the molecular basis of this disease and opens up the opportunity to develop rational therapies targeting the placental dysfunction causal to preeclampsia.

Meta-analysis of the association of the SLC6A3 3'-UTR VNTR with cognition.

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Ettinger, Ulrich; Merten, Natascha; Kambeitz, Joseph

2016-01-01

The gene coding for the dopamine transporter (DAT), SLC6A3, contains a 40-base pair variable number of tandem repeats (VNTR) polymorphism (rs28363170) in its 3' untranslated region. This VNTR has been associated with attention deficit hyperactivity disorder (ADHD) and has been investigated in relation to cognition and brain function. Here, we report the results of a comprehensive meta-analysis with meta-regression examining the association of the VNTR with different domains of cognition in healthy adults. We extracted data from 28 independent studies and carried out meta-analyses for associations with working memory (k=10 samples, N=1193 subjects), inhibition (k=8 samples, N=829 subjects), executive functions including inhibition (k=10 samples, N=984 subjects), attention (k=6 samples, N=742 subjects) and declarative long-term memory (k=5 samples, N=251 subjects). None of the investigated dimensions showed significant associations with the VNTR (all p>0.26). Meta-regression including year of publication, gender, age, ethnicity and percentage of 10R-homozygotes similarly did not attain significance. We conclude that there is no evidence that rs28363170 may be a significant predictor of cognitive function in healthy adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

Diet influenced tooth erosion prevalence in children and adolescents: Results of a meta-analysis and meta-regression

NARCIS (Netherlands)

Salas, M.M.; Nascimento, G.G.; Vargas-Ferreira, F.; Tarquinio, S.B.; Huysmans, M.C.D.N.J.M.; Demarco, F.F.

2015-01-01

OBJECTIVE: The aim of the present study was to assess the influence of diet in tooth erosion presence in children and adolescents by meta-analysis and meta-regression. DATA: Two reviewers independently performed the selection process and the quality of studies was assessed. SOURCES: Studies

First-trimester exposure to metformin and risk of birth defects: a systematic review and meta-analysis.

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Cassina, Matteo; Donà, Marta; Di Gianantonio, Elena; Litta, Pietro; Clementi, Maurizio

2014-01-01

Metformin is generally considered a non-teratogenic drug; however, only a few studies specifically designed to assess the rate of congenital anomalies after metformin use have been published in the literature. The objects of the present study were to review all of the prospective and retrospective studies reporting on women treated with metformin at least during the first trimester of their pregnancy and to estimate the overall rate of major birth defects. Databases were searched for English language articles until December 2013. Inclusion criteria for the meta-analysis were: a case group of women with PCOS or pre-pregnancy type 2 diabetes and first-trimester exposure to metformin; a disease-matched control group which was not exposed to metformin or other oral anti-diabetic agents; and a list of the major anomalies in both the study and the control groups. A random effects model was used for the meta-analysis of data, using odds ratios. Studies not fulfilling the inclusion criteria for the meta-analysis but reporting relevant data on major malformations in women diagnosed with PCOS were then used to estimate the overall birth defects rate. Meta-analysis of nine controlled studies with women affected by PCOS detected that the rate of major birth defects in the metformin-exposed group was not statistically increased compared with the disease-matched control group and that there was no significant heterogeneity among the studies. The metformin-exposed sample was composed of 351 pregnancies and the OR of major birth defects was 0.86 (95% confidence interval: 0.18-4.08; Pheterogeneity = 0.71). By evaluating all of the non-overlapping PCOS studies reported in the literature, even those without an appropriate control group, the overall rate of major anomalies was 0.6% in the sample of 517 women who discontinued the therapy upon conception or confirmation of pregnancy and 0.5% in the sample of 634 women who were treated with metformin throughout the first trimester of

The prevalence of chronic fatigue syndrome/ myalgic encephalomyelitis: a meta-analysis

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Johnston S

2013-03-01

Full Text Available Samantha Johnston,1 Ekua W Brenu,1 Donald Staines,1,2 Sonya Marshall-Gradisnik1 1Griffith Health Institute, School of Medical Sciences, National Centre for Neuroimmunology and Emerging Diseases, Griffith University, Parklands, QLD, Australia; 2Gold Coast Public Health Unit, Queensland Health, Robina, QLD, Australia Purpose: To perform a meta-analysis to examine variability among prevalence estimates for CFS/ME, according to the method of assessment used. Methods: Databases were systematically searched for studies on CFS/ME prevalence in adults that applied the 1994 Centers for Disease Control (CDC case definition.1 Estimates were categorized into two methods of assessment: self-reporting of symptoms versus clinical assessment of symptoms. Meta-analysis was performed to pool prevalences by assessment using random effects modeling. This was stratified by sample setting (community or primary care and heterogeneity was examined using the I2 statistic. Results: Of 216 records found, 14 studies were considered suitable for inclusion. The pooled prevalence for self-reporting assessment was 3.28% (95% CI: 2.24–4.33 and 0.76% (95% CI: 0.23–1.29 for clinical assessment. High variability was observed among self-reported estimates, while clinically assessed estimates showed greater consistency. Conclusion: The observed heterogeneity in CFS/ME prevalence may be due to differences in method of assessment. Stakeholders should be cautious of prevalence determined by the self-reporting of symptoms alone. The 1994 CDC case definition appeared to be the most reliable clinical assessment tool available at the time of these studies. Improving clinical case definitions and their adoption internationally will enable better comparisons of findings and inform health systems about the true burden of CFS/ME. Keywords: chronic fatigue syndrome, myalgic encephalomyelitis, prevalence, meta-analysis

Systematic review and meta-analysis of the effects of football heading.

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Kontos, Anthony P; Braithwaite, Rock; Chrisman, Sara P D; McAllister-Deitrick, Jamie; Symington, Larissa; Reeves, Valerie L; Collins, Michael W

2017-08-01

The objective of this study was to provide a meta-analysis examining the effects of football heading. Meta-analytical review on football heading effects on neurocognitive performance, cognition and symptom reports. Combinations of the key terms were entered into the following electronic database search engines: Cochrane Libraries, PyscARTICLE, PyscINFO, PubMed, ProQuest, SPORTDiscus and Web of Science on 7 July 2016. The following inclusion criteria were used to determine eligibility for studies: (1) the study examined and reported on soccer athletes; (2) the population's age, sex and sport position was described; (3) cognitive function, symptoms, balance or other outcomes were quantitatively measured; (4) football heading exposure was quantitatively measured between at least two groups and (5) the study was written in the English language after December 1979. The literature search process identified 467 unique studies. After applying exclusion criteria, 28 studies remained. Included studies had a total of 2288 participants (female participants =933, male participants =1355), aged 13-70 years. The overall results of random effects modelling of football heading were found to be inconclusive across all outcomes, groups and time points. No moderating variables related to methodological, sample or study characteristics were supported in the analysis; age was a potential moderating variable. We provide the first meta-analytical review of football heading effects aggregated from multiple studies and extended findings from a recent systematic review of the effects of football heading. Our analysis indicates no overall effect for heading a football on adverse outcomes. 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/.

CNV-association meta-analysis in 191,161 European adults reveals new loci associated with anthropometric traits

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Macé, Aurélien; Tuke, Marcus A; Deelen, Patrick

2017-01-01

There are few examples of robust associations between rare copy number variants (CNVs) and complex continuous human traits. Here we present a large-scale CNV association meta-analysis on anthropometric traits in up to 191,161 adult samples from 26 cohorts. The study reveals five CNV associations......-scale genome-wide meta-analysis of structural variation and find rare CNVs associated with height, weight and BMI with large effect sizes.......)). Burden analysis shows a 0.41 cm decrease in height, a 0.003 increase in waist-to-hip ratio and increase in BMI by 0.14 kg/m(2) for each Mb of total deletion burden (P = 2.5 × 10(-10), 6.0 × 10(-5), and 2.9 × 10(-3)). Our study provides evidence that the same genes (e.g., MC4R, FIBIN, and FMO5) harbor...

Efficacy of escitalopram compared to citalopram: a meta-analysis.

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Montgomery, Stuart; Hansen, Thomas; Kasper, Siegfried

2011-03-01

The aim of this review was to assess the clinical relevance of the relative antidepressant efficacy of escitalopram and citalopram by meta-analysis. Studies in major depressive disorder (MDD) with both escitalopram and citalopram treatment arms were identified. Adult patients had to meet DSM-IV criteria for MDD. The primary outcome measure was the treatment difference in Montgomery-Asberg Depression Rating Scale (MADRS) total score at week 8 (or last assessment if escitalopram, n=995; citalopram, n=1014). Escitalopram was significantly more effective than citalopram in overall treatment effect, with an estimated mean treatment difference of 1.7 points at week 8 (or last assessment if escitalopram. In this meta-analysis, the statistically significant superior efficacy of escitalopram compared to citalopram was shown to be clinically relevant.

Association between increase in fixed penalties and road safety outcomes: A meta-analysis.

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Elvik, Rune

2016-07-01

Studies that have evaluated the association between increases in traffic fine amounts (fixed penalties) and changes in compliance with road traffic law or the number of accidents are synthesised by means of meta-analysis. The studies were few and different in many respects. Nine studies were included in the meta-analysis of changes in compliance. Four studies were included in the meta-analysis of changes in accidents. Increasing traffic fines was found to be associated with small changes in the rate of violations. The changes were non-linear. For increases up to about 100%, violations were reduced. For larger increases, no reduction in violations was found. A small reduction in fatal accidents was associated with increased fixed penalties, varying between studies from less than 1-12%. The main pattern of changes in violations was similar in the fixed-effects and random-effects models of meta-analysis, meta-regression and when simple (non-weighted) mean values were computed. The main findings are thus robust, although most of the primary studies did not control very well for potentially confounding factors. Summary estimates of changes in violations or accidents should be treated as provisional and do not necessarily reflect causal relationships. Copyright © 2016 Elsevier Ltd. All rights reserved.

[The meta-analysis of data from individual patients].

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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,

The Effects of Massage Therapy on Pain and Anxiety after Surgery: A Systematic Review and Meta-Analysis.

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Kukimoto, Yukiko; Ooe, Noriko; Ideguchi, Norio

2017-12-01

Pain management is critical for patients after surgery, but current pain management methods are not always adequate. Massage therapy may be a therapeutic complementary therapy for pain. Many researchers have investigated the effects of massage therapy on post-operative pain, but there have been no systematic reviews and meta-analysis of its efficacy for post-operative patients. Our objective was to assess the effects of massage therapy on pain management among post-operative patients by conducting a systematic review and meta-analysis. The databases searched included MEDLINE, CINAHL, and the Cochrane Library's CENTRAL. To assess the effects of massage therapy on post-operative pain and anxiety, we performed a meta-analysis and calculated standardized mean difference with 95% CIs (Confidential Intervals) as a summary effect. Ten randomized controlled trials were selected (total sample size = 1,157). Meta-analysis was conducted using subgroup analysis. The effect of single dosage massage therapy on post-operative pain showed significant improvement (-0.49; 95% confidence intervals -0.64, -0.34; p < .00001) and low heterogeneity (p = .39, I 2 = 4%), sternal incisions showed significant improvement in pain (-0.68; -0.91, -0.46; p< .00001) and low heterogeneity (p = .76, I 2 = 0%). The anxiety subgroups showed substantial heterogeneity. The findings of this study revealed that massage therapy may alleviate post-operative pain, although there are limits on generalization of these findings due to low methodological quality in the reviewed studies. Copyright © 2017 American Society for Pain Management Nursing. Published by Elsevier Inc. All rights reserved.

Self-reported interoceptive deficits in eating disorders: A meta-analysis of studies using the eating disorder inventory.

Science.gov (United States)

Jenkinson, Paul M; Taylor, Lauren; Laws, Keith R

2018-07-01

An impairment of the ability to sense the physiological condition of the body - interoception - has long been proposed as central to the onset and maintenance of eating disorders. More recent attention to this topic has generally indicated the presence of interoceptive deficits in individuals with an eating disorder diagnosis; however, possible links with specific diagnosis, BMI, age, illness duration, depression, and alexithymia remain unclear from individual studies. This meta-analysis aimed to provide a necessary quantitative overview of self-reported interoceptive deficits in eating disorder populations, and the relationship between these deficits and the previously mentioned factors. Using a random effects model, our meta-analysis assessed the magnitude of differences in interoceptive abilities as measured using the Eating Disorder Inventory in 41 samples comparing people with eating disorders (n = 4308) and healthy controls (n = 3459). Follow-up and moderator analysis was conducted, using group comparisons and meta-regressions. We report a large pooled effect size of 1.62 for eating disorders with some variation between diagnostic groups. Further moderator analysis showed that BMI, age and alexithymia were significant predictors of overall effect size. This meta-analysis is the first to confirm that large interoceptive deficits occur in a variety of eating disorders and crucially, in those who have recovered. These deficits may be useful in identifying and distinguishing eating disorders. Future research needs to consider both objective and subjective measures of interoception across different types of eating disorders and may fruitfully examine interoception as a possible endophenotype and target for treatment. Copyright © 2018 Elsevier Inc. All rights reserved.

Plasma exchange for renal vasculitis and idiopathic rapidly progressive glomerulonephritis: a meta-analysis

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Walsh, Michael; Catapano, Fausta; Szpirt, Wladimir

2011-01-01

Plasma exchange may be effective adjunctive treatment for renal vasculitis. We performed a systematic review and meta-analysis of randomized controlled trials of plasma exchange for renal vasculitis.......Plasma exchange may be effective adjunctive treatment for renal vasculitis. We performed a systematic review and meta-analysis of randomized controlled trials of plasma exchange for renal vasculitis....

Indirect health costs in ulcerative colitis and Crohn's disease: a systematic review and meta-analysis.

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Kawalec, Paweł; Malinowski, Krzysztof Piotr

2015-04-01

The aim of this systematic review was to collect all current data on indirect costs related to inflammatory bowel disease as well as assessing homogeneity and comparability, and conducting a meta-analysis. Costs were collected using databases from Medline, Embase and Centre for Reviews and Dissemination databases, then average annual cost per patient was calculated and expressed in 2013-rate USD using the consumer price index and purchasing power parity (scenario 1) and then adjusted to specific gross domestic product (scenario 2) to make them comparable. The studies were then included in quantitative synthesis using the meta-analysis and bootstrap methods. This systematic review was carried out and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. From 18 publications, overall annual indirect costs per patient as a result of the quantitative synthesis among all studies eligible for meta-analysis ranged from US$2425.01-US$9622.15 depending on the scenario and model used for analysis. The cost of presenteeism was assessed in only two studies. Considering heterogeneity among all identified studies random-effect model presented the most accurate results of meta-analysis equal to US$7189.27 and US$9622.15 per patient per year for scenario 1 and scenario 2, respectively. This systematic review revealed the existence of a relatively small number of studies that reported on the great economic burden of the disease upon society. A great variety of methodologies and cost components resulted in a very large discrepancy in indirect costs and made meta-analysis difficult to perform, so two scenarios were considered and meta-analysis conducted in subgroups to make data more comparable.

Hand dysfunction in type 2 diabetes mellitus: Systematic review with meta-analysis.

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Gundmi, Shubha; Maiya, Arun G; Bhat, Anil K; Ravishankar, N; Hande, Manjunatha H; Rajagopal, K V

2018-03-01

People with type 2 diabetes mellitus frequently show complications in feet and hands. However, the literature has mostly focused on foot complications. The disease can affect the strength and dexterity of the hands, thereby reducing function. This systematic review and meta-analysis focused on identifying the existing evidence on how type 2 diabetes mellitus affects hand strength, dexterity and function. We searched MEDLINE via PubMed, CINHAL, Scopus and Web of Science, and the Cochrane central register of controlled trials for reports of studies of grip and pinch strength as well as hand dexterity and function evaluated by questionnaires comparing patients with type 2 diabetes mellitus and healthy controls that were published between 1990 and 2017. Data are reported as standardized mean difference (SMD) or mean difference (MD) and 95% confidence intervals (CIs). Among 2077 records retrieved, only 7 full-text articles were available for meta-analysis. For both the dominant and non-dominant hand, type 2 diabetes mellitus negatively affected grip strength (SMD: -1.03; 95% CI: -2.24 to 0.18 and -1.37, -3.07 to 0.33) and pinch strength (-1.09, -2.56 to 0.38 and -1.12, -2.73 to 0.49), although not significantly. Dexterity of the dominant hand did not differ between diabetes and control groups but was poorer for the non-dominant hand, although not significantly. Hand function was worse for diabetes than control groups in 2 studies (MD: -8.7; 95% CI: -16.88 to -1.52 and 4.69, 2.03 to 7.35). This systematic review with meta-analysis suggested reduced hand function, specifically grip and pinch strength, for people with type 2 diabetes mellitus versus healthy controls. However, the sample size for all studies was low. Hence, we need studies with adequate sample size and randomized controlled trials to provide statistically significant results. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Prevalence of polycystic ovary syndrome and its associated complications in Iranian women: A meta-analysis.

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Jalilian, Anahita; Kiani, Faezeh; Sayehmiri, Fatemeh; Sayehmiri, Kourosh; Khodaee, Zahra; Akbari, Malihe

2015-10-01

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age and is the most common cause of infertility due to anovulation. There is no single criterion for the diagnosis of this syndrome. The purpose of this study was to investigate the prevalence of PCOS and its associated complications in Iranian women using meta-analysis method. Prevalence of PCOS was investigated from the SID, Goggle scholar, PubMed, Magiran, Irandoc, and Iranmedex, and weighting of each study was calculated according to sample size and prevalence of the binomial distribution. Data were analyzed using a random-effects model meta-analysis (Random effects model) and the software R and Stata Version 11.2. 30 studies conducted between the years 2006 to 2011 were entered into meta-analysis. The total sample size was 19, 226 women aged between 10-45 years. The prevalence of PCOS based on National institute of child health and human disease of the U.S was, 6.8% (95 % CI: 4.11-8.5), based on Rotterdam was 19.5% (95 % CI: 2.24-8.14), and based on ultrasound was 4.41% (95% CI: 5.68-4.14). Also, the prevalence of hirsutism was estimated to be 13%, acne 26%, androgenic alopecia 9%, menstrual disorders 28%, overweight 21%, obesity 19%, and infertility 8%. The prevalence of PCOS in Iran is not high. However, given the risk of complications such as heart disease - cardiovascular and infertility, prevention of PCOS is important; we suggest that health officials must submit plans for the community in this respect.

Therapy of bovine endometritis with prostaglandin F2α: a meta-analysis.

Science.gov (United States)

Haimerl, P; Heuwieser, W; Arlt, S

2013-05-01

The objective of the conducted meta-analysis was to assess the efficacy of the treatment of bovine endometritis with PGF(2α) by statistical means. Postpartum uterine infections have a high prevalence and a very negative effect on reproductive performance in dairy cattle. Because of a wide discordance between research results, a meta-analysis of the efficacy of the treatment of bovine endometritis with PGF(2α) was conducted. A comprehensive literature search was performed using online databases to reveal a total of 2,307 references. In addition, 5 articles were retrieved by reviewing citations. After applying specific exclusion criteria and evaluating specific evidence parameters, 5 publications, comprising 6 trials, were eligible for being analyzed by means of meta-analysis. Data for each trial were extracted and analyzed using meta-analysis software Review Manager (version 5.1; The Nordic Cochrane Centre, Copenhagen, Denmark). Estimated effect sizes of PGF(2α) were calculated on calving to first service and calving to conception interval. Prostaglandin F(2α) treatment of cows with chronic endometritis had a negative effect on both reproductive performance parameters. Heterogeneity was substantial for calving to first service and calving to conception interval [I(2) (measure of variation beyond chance)=100 and 87%, respectively]; therefore, random-effects models were used. Sensitivity analysis as well as subgroup analysis showed that the performance of randomization was influential in modifying effect size of PGF(2α) treatment. The funnel plot illustrated a publication bias toward smaller studies that reported a prolonged calving to conception interval after a PGF(2α) treatment. We conclude that the investigation of this subject by means of meta-analysis did not reveal an improvement of reproductive performance of cows with endometritis after treatment with PGF(2α). Furthermore, there is a shortage of comparable high quality studies investigating

Do jobs follow people or people follow jobs? A meta-analysis of Carlino–Mills studies

NARCIS (Netherlands)

Hoogstra, Gerke J.; Van Dijk, Jouke; Florax, Raymond J. G. M.

2017-01-01

Do jobs follow people or people follow jobs? A meta-analysis of Carlino–Mills studies. Spatial Economic Analysis. This study examines the classic question as to whether ‘jobs follow people’ or ‘people follow jobs’ by performing a meta-analysis of 321 results from 64 Carlino–Mills studies. It is

Periodontal disease and risk of preeclampsia: a meta-analysis of observational studies.

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Ben-Juan Wei

Full Text Available BACKGROUND: Many epidemiological studies have found a positive association between periodontal disease (PD and the risk of preeclampsia, but the magnitude of this association varies and independent studies have reported conflicting findings. We performed a meta-analysis to ascertain the relationship between PD and preeclampsia. METHODS: The PubMed database was searched up to January 12, 2013, for relevant observational studies on an association between PD and the risk of preeclampsia. Data were extracted and analyzed independently by two authors. The meta-analysis was performed using comprehensive meta-analysis software. RESULTS: Thirteen observational case-control studies and two cohort studies, involving 1089 preeclampsia patients, were identified. Based on a random-effects meta-analysis, a significant association between PD and preeclampsia was identified (odds ratio = 2.79, 95% confidence interval CI, 2.01-3.01, P<0.0001. CONCLUSIONS: Although the causality remains unclear, the association between PD and preeclampsia may reflect the induction of PD by the preeclamptic state, or it may be part of an overall exaggerated inflammatory response to pregnancy. Larger randomized controlled trials with preeclampsia as the primary outcome and pathophysiological studies are required to explore causality and to dissect the biological mechanisms involved.

Simpson's paradox and calculation of number needed to treat from meta-analysis

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Cates Christopher J

2002-01-01

Full Text Available Abstract Background Calculation of numbers needed to treat (NNT is more complex from meta-analysis than from single trials. Treating the data as if it all came from one trial may lead to misleading results when the trial arms are imbalanced. Discussion An example is shown from a published Cochrane review in which the benefit of nursing intervention for smoking cessation is shown by formal meta-analysis of the individual trial results. However if these patients were added together as if they all came from one trial the direction of the effect appears to be reversed (due to Simpson's paradox. Whilst NNT from meta-analysis can be calculated from pooled Risk Differences, this is unlikely to be a stable method unless the event rates in the control groups are very similar. Since in practice event rates vary considerably, the use a relative measure, such as Odds Ratio or Relative Risk is advocated. These can be applied to different levels of baseline risk to generate a risk specific NNT for the treatment. Summary The method used to calculate NNT from meta-analysis should be clearly stated, and adding the patients from separate trials as if they all came from one trial should be avoided.

Systematic review and meta-analysis of glyphosate exposure and risk of lymphohematopoietic cancers.

Science.gov (United States)

Chang, Ellen T; Delzell, Elizabeth

2016-01-01

This systematic review and meta-analysis rigorously examines the relationship between glyphosate exposure and risk of lymphohematopoietic cancer (LHC) including NHL, Hodgkin lymphoma (HL), multiple myeloma (MM), and leukemia. Meta-relative risks (meta-RRs) were positive and marginally statistically significant for the association between any versus no use of glyphosate and risk of NHL (meta-RR = 1.3, 95% confidence interval (CI) = 1.0-1.6, based on six studies) and MM (meta-RR = 1.4, 95% CI = 1.0-1.9; four studies). Associations were statistically null for HL (meta-RR = 1.1, 95% CI = 0.7-1.6; two studies), leukemia (meta-RR = 1.0, 95% CI = 0.6-1.5; three studies), and NHL subtypes except B-cell lymphoma (two studies each). Bias and confounding may account for observed associations. Meta-analysis is constrained by few studies and a crude exposure metric, while the overall body of literature is methodologically limited and findings are not strong or consistent. Thus, a causal relationship has not been established between glyphosate exposure and risk of any type of LHC.

Exhaled carbon monoxide in asthmatics: a meta-analysis

Directory of Open Access Journals (Sweden)

Huang Mao

2010-04-01

Full Text Available Abstract Background The non-invasive assessment of airway inflammation is potentially advantageous in asthma management. Exhaled carbon monoxide (eCO measurement is cheap and has been proposed to reflect airway inflammation and oxidative stress but current data are conflicting. The purpose of this meta-analysis is to determine whether eCO is elevated in asthmatics, is regulated by steroid treatment and reflects disease severity and control. Methods A systematic search for English language articles published between 1997 and 2009 was performed using Medline, Embase and Cochrane databases. Observational studies comparing eCO in non-smoking asthmatics and healthy subjects or asthmatics before and after steroid treatment were included. Data were independently extracted by two investigators and analyzed to generate weighted mean differences using either a fixed or random effects meta-analysis depending upon the degree of heterogeneity. Results 18 studies were included in the meta-analysis. The eCO level was significantly higher in asthmatics as compared to healthy subjects and in intermittent asthma as compared to persistent asthma. However, eCO could not distinguish between steroid-treated asthmatics and steroid-free patients nor separate controlled and partly-controlled asthma from uncontrolled asthma in cross-sectional studies. In contrast, eCO was significantly reduced following a course of corticosteroid treatment. Conclusions eCO is elevated in asthmatics but levels only partially reflect disease severity and control. eCO might be a potentially useful non-invasive biomarker of airway inflammation and oxidative stress in nonsmoking asthmatics.

Meta-Analysis of Massage Therapy on Cancer Pain.

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Lee, Sook-Hyun; Kim, Jong-Yeop; Yeo, Sujung; Kim, Sung-Hoon; Lim, Sabina

2015-07-01

Cancer pain is the most common complaint among patients with cancer. Conventional treatment does not always relieve cancer pain satisfactorily. Therefore, many patients with cancer have turned to complementary therapies to help them with their physical, emotional, and spiritual well-being. Massage therapy is increasingly used for symptom relief in patients with cancer. The current study aimed to investigate by meta-analysis the effects of massage therapy for cancer patients experiencing pain. Nine electronic databases were systematically searched for studies published through August 2013 in English, Chinese, and Korean. Methodological quality was assessed using the Physiotherapy Evidence Database (PEDro) and Cochrane risk-of-bias scales. Twelve studies, including 559 participants, were used in the meta-analysis. In 9 high-quality studies based on the PEDro scale (standardized mean difference, -1.24; 95% confidence interval, -1.72 to -0.75), we observed reduction in cancer pain after massage. Massage therapy significantly reduced cancer pain compared with no massage treatment or conventional care (standardized mean difference, -1.25; 95% confidence interval, -1.63 to -0.87). Our results indicate that massage is effective for the relief of cancer pain, especially for surgery-related pain. Among the various types of massage, foot reflexology appeared to be more effective than body or aroma massage. Our meta-analysis indicated a beneficial effect of massage for relief of cancer pain. Further well-designed, large studies with longer follow-up periods are needed to be able to draw firmer conclusions regarding the effectiveness. © The Author(s) 2015.

Gardening is beneficial for health: A meta-analysis.

Science.gov (United States)

Soga, Masashi; Gaston, Kevin J; Yamaura, Yuichi

2017-03-01

There is increasing evidence that gardening provides substantial human health benefits. However, no formal statistical assessment has been conducted to test this assertion. Here, we present the results of a meta-analysis of research examining the effects of gardening, including horticultural therapy, on health. We performed a literature search to collect studies that compared health outcomes in control (before participating in gardening or non-gardeners) and treatment groups (after participating in gardening or gardeners) in January 2016. The mean difference in health outcomes between the two groups was calculated for each study, and then the weighted effect size determined both across all and sets of subgroup studies. Twenty-two case studies (published after 2001) were included in the meta-analysis, which comprised 76 comparisons between control and treatment groups. Most studies came from the United States, followed by Europe, Asia, and the Middle East. Studies reported a wide range of health outcomes, such as reductions in depression, anxiety, and body mass index, as well as increases in life satisfaction, quality of life, and sense of community. Meta-analytic estimates showed a significant positive effect of gardening on the health outcomes both for all and sets of subgroup studies, whilst effect sizes differed among eight subgroups. Although Egger's test indicated the presence of publication bias, significant positive effects of gardening remained after adjusting for this using trim and fill analysis. This study has provided robust evidence for the positive effects of gardening on health. A regular dose of gardening can improve public health.

Gardening is beneficial for health: A meta-analysis

Directory of Open Access Journals (Sweden)

Masashi Soga

2017-03-01

Full Text Available There is increasing evidence that gardening provides substantial human health benefits. However, no formal statistical assessment has been conducted to test this assertion. Here, we present the results of a meta-analysis of research examining the effects of gardening, including horticultural therapy, on health. We performed a literature search to collect studies that compared health outcomes in control (before participating in gardening or non-gardeners and treatment groups (after participating in gardening or gardeners in January 2016. The mean difference in health outcomes between the two groups was calculated for each study, and then the weighted effect size determined both across all and sets of subgroup studies. Twenty-two case studies (published after 2001 were included in the meta-analysis, which comprised 76 comparisons between control and treatment groups. Most studies came from the United States, followed by Europe, Asia, and the Middle East. Studies reported a wide range of health outcomes, such as reductions in depression, anxiety, and body mass index, as well as increases in life satisfaction, quality of life, and sense of community. Meta-analytic estimates showed a significant positive effect of gardening on the health outcomes both for all and sets of subgroup studies, whilst effect sizes differed among eight subgroups. Although Egger's test indicated the presence of publication bias, significant positive effects of gardening remained after adjusting for this using trim and fill analysis. This study has provided robust evidence for the positive effects of gardening on health. A regular dose of gardening can improve public health.

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.

Genome-Wide Meta-Analysis of Sciatica in Finnish Population.

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Susanna Lemmelä

Full Text Available Sciatica or the sciatic syndrome is a common and often disabling low back disorder in the working-age population. It has a relatively high heritability but poorly understood molecular mechanisms. The Finnish population is a genetic isolate where small founder population and bottleneck events have led to enrichment of certain rare and low frequency variants. We performed here the first genome-wide association (GWAS and meta-analysis of sciatica. The meta-analysis was conducted across two GWAS covering 291 Finnish sciatica cases and 3671 controls genotyped and imputed at 7.7 million autosomal variants. The most promising loci (p<1x10-6 were replicated in 776 Finnish sciatica patients and 18,489 controls. We identified five intragenic variants, with relatively low frequencies, at two novel loci associated with sciatica at genome-wide significance. These included chr9:14344410:I (rs71321981 at 9p22.3 (NFIB gene; p = 1.30x10-8, MAF = 0.08 and four variants at 15q21.2: rs145901849, rs80035109, rs190200374 and rs117458827 (MYO5A; p = 1.34x10-8, MAF = 0.06; p = 2.32x10-8, MAF = 0.07; p = 3.85x10-8, MAF = 0.06; p = 4.78x10-8, MAF = 0.07, respectively. The most significant association in the meta-analysis, a single base insertion rs71321981 within the regulatory region of the transcription factor NFIB, replicated in an independent Finnish population sample (p = 0.04. Despite identifying 15q21.2 as a promising locus, we were not able to replicate it. It was differentiated; the lead variants within 15q21.2 were more frequent in Finland (6-7% than in other European populations (1-2%. Imputation accuracies of the three significantly associated variants (chr9:14344410:I, rs190200374, and rs80035109 were validated by genotyping. In summary, our results suggest a novel locus, 9p22.3 (NFIB, which may be involved in susceptibility to sciatica. In addition, another locus, 15q21.2, emerged as a promising one, but failed to replicate.

The Economic Value of Mangroves: A Meta-Analysis

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Marwa E. Salem

2012-03-01

Full Text Available This paper presents a synthesis of the mangrove ecosystem valuation literature through a meta-regression analysis. The main contribution of this study is that it is the first meta-analysis focusing solely on mangrove forests, whereas previous studies have included different types of wetlands. The number of studies included in the regression analysis is 44 for a total of 145 observations. We include several regressions with the objective of addressing outliers in the data as well as the possible correlations between observations of the same study. We also investigate possible interaction effects between type of service and GDP per capita. Our findings indicate that mangroves exhibit decreasing returns to scale, that GDP per capita has a positive effect on mangrove values and that using the replacement cost and contingent valuation methods produce higher estimates than do other methods. We also find that there are statistically significant interaction effects that influence the data. Finally, the results indicate that employing weighted regressions provide a better fit than others. However, in terms of forecast performance we find that all the estimated models performed similarly and were not able to conclude decisively that one outperforms the other.

Pooling, meta-analysis, and the evaluation of drug safety

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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.

A comparison of national guidelines for network meta-analysis.

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Laws, Andrew; Kendall, Robyn; Hawkins, Neil

2014-07-01

Within technology appraisals, it is necessary to compare the complete set of treatments that may be used in the patient group under consideration. Randomized controlled trials are a key source of evidence for these comparisons. The techniques of network meta-analysis allow the networks of trial evidence to be evaluated to obtain estimates of comparative efficacy between sets of treatments. These techniques may be the only source of estimates of comparative effectiveness if trials directly comparing the treatments of interest have not been conducted, and may provide useful additional evidence if both direct and indirect comparisons exist. We examined both published and draft guidelines from reimbursement and health technology appraisal bodies, and considered their recommendations using appropriate methodology for the conduct of indirect comparisons and the assessments of their validity. Guidelines from 33 countries were reviewed. Of these, guidelines from 9 countries-Australia, Belgium, Canada, France, Germany, Scotland, Spain, South Africa, and the United Kingdom (England and Wales)-included detailed recommendations on the conduct of network meta-analysis. The recommendations were summarized. No two recommendations from the multiple national guidelines are mutually exclusive. It is possible to perform one network meta-analysis for submission to multiple national jurisdictions. Copyright © 2014 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Predicting adult obesity from childhood obesity : A systematic review and meta-analysis

OpenAIRE

Simmonds, M.; Llewellyn, A.; Owen, C. G.; Woolacott, N.

2016-01-01

A systematic review and meta-analysis was performed to investigate the ability of simple measures of childhood obesity such as body mass index (BMI) to predict future obesity in adolescence and adulthood. Large cohort studies, which measured obesity both in childhood and in later adolescence or adulthood, using any recognized measure of obesity were sought. Study quality was assessed. Studies were pooled using diagnostic meta-analysis methods. Fifteen prospective cohort studies were included ...

An efficient Bayesian meta-analysis approach for studying cross-phenotype genetic associations.

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Arunabha Majumdar

2018-02-01

Full Text Available Simultaneous analysis of genetic associations with multiple phenotypes may reveal shared genetic susceptibility across traits (pleiotropy. For a locus exhibiting overall pleiotropy, it is important to identify which specific traits underlie this association. We propose a Bayesian meta-analysis approach (termed CPBayes that uses summary-level data across multiple phenotypes to simultaneously measure the evidence of aggregate-level pleiotropic association and estimate an optimal subset of traits associated with the risk locus. This method uses a unified Bayesian statistical framework based on a spike and slab prior. CPBayes performs a fully Bayesian analysis by employing the Markov Chain Monte Carlo (MCMC technique Gibbs sampling. It takes into account heterogeneity in the size and direction of the genetic effects across traits. It can be applied to both cohort data and separate studies of multiple traits having overlapping or non-overlapping subjects. Simulations show that CPBayes can produce higher accuracy in the selection of associated traits underlying a pleiotropic signal than the subset-based meta-analysis ASSET. We used CPBayes to undertake a genome-wide pleiotropic association study of 22 traits in the large Kaiser GERA cohort and detected six independent pleiotropic loci associated with at least two phenotypes. This includes a locus at chromosomal region 1q24.2 which exhibits an association simultaneously with the risk of five different diseases: Dermatophytosis, Hemorrhoids, Iron Deficiency, Osteoporosis and Peripheral Vascular Disease. We provide an R-package 'CPBayes' implementing the proposed method.

Understanding the physical attractiveness literature: Qualitative reviews versus meta-analysis.

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Feingold, Alan

2017-01-01

The target article is a qualitative review of selected findings in the physical attractiveness literature. This commentary explains why the meta-analytic approach, frequently used by other attractiveness reviewers, is preferable for drawing unbiased conclusions about the effects of attractiveness. The article's main contribution is affording a foundation for subsequent meta-analysis of the studies discussed in a subjective fashion.

Grain yield increase in cereal variety mixtures: A meta-analysis of field trials

DEFF Research Database (Denmark)

Kiær, Lars Pødenphant; Skovgaard, Ib; Østergård, Hanne

2009-01-01

on grain yield. To investigate the prevalence and preconditions for positive mixing effects, reported grain yields of variety mixtures and pure variety stands were obtained from previously published variety trials, converted into relative mixing effects and combined using meta-analysis. Furthermore...... as meeting the criteria for inclusion in the meta-analysis; on the other hand, nearly 200 studies were discarded. The accepted studies reported results on both winter and spring types of each crop species. Relative mixing effects ranged from 30% to 100% with an overall meta-estimate of at least 2.7% (p

Effects of clinical pathways in the joint replacement: a meta-analysis

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Faggiano F

2009-07-01

Full Text Available Abstract Background A meta-analysis was performed to evaluate the use of clinical pathways for hip and knee joint replacements when compared with standard medical care. The impact of clinical pathways was evaluated assessing the major outcomes of in-hospital hip and knee joint replacement processes: postoperative complications, number of patients discharged at home, length of in-hospital stay and direct costs. Methods Medline, Cinahl, Embase and the Cochrane Central Register of Controlled Trials were searched. The search was performed from 1975 to 2007. Each study was assessed independently by two reviewers. The assessment of methodological quality of the included studies was based on the Jadad methodological approach and on the New Castle Ottawa Scale. Data analysis abided by the guidelines set out by The Cochrane Collaboration regarding statistical methods. Meta-analyses were performed using RevMan software, version 4.2. Results Twenty-two studies met the study inclusion criteria and were included in the meta-analysis for a total sample of 6,316 patients. The aggregate overall results showed significantly fewer patients suffering postoperative complications in the clinical pathways group when compared with the standard care group. A shorter length of stay in the clinical pathway group was also observed and lower costs during hospital stay were associated with the use of the clinical pathways. No significant differences were found in the rates of discharge to home. Conclusion The results of this meta-analysis show that clinical pathways can significantly improve the quality of care even if it is not possible to conclude that the implementation of clinical pathways is a cost-effective process, because none of the included studies analysed the cost of the development and implementation of the pathways. Based on the results we assume that pathways have impact on the organisation of care if the care process is structured in a standardised way

CNV-association meta-analysis in 191,161 European adults reveals new loci associated with anthropometric traits

NARCIS (Netherlands)

Macé, Aurélien; Tuke, Marcus A; Deelen, Patrick; Kristiansson, Kati; Mattsson, Hannele; Nõukas, Margit; Sapkota, Yadav; Schick, Ursula; Porcu, Eleonora; Rüeger, Sina; McDaid, Aaron F; Porteous, David; Winkler, Thomas W; Salvi, Erika; Shrine, Nick; Liu, Xueping; Ang, Wei Q; Zhang, Weihua; Feitosa, Mary F; Venturini, Cristina; van der Most, Peter J; Rosengren, Anders; Wood, Andrew R; Beaumont, Robin N; Jones, Samuel E; Ruth, Katherine S; Yaghootkar, Hanieh; Tyrrell, Jessica; Havulinna, Aki S; Boers, Harmen; Mägi, Reedik; Kriebel, Jennifer; Müller-Nurasyid, Martina; Perola, Markus; Nieminen, Markku; Lokki, Marja-Liisa; Kähönen, Mika; Viikari, Jorma S; Geller, Frank; Lahti, Jari; Palotie, Aarno; Koponen, Päivikki; Lundqvist, Annamari; Rissanen, Harri; Bottinger, Erwin P; Afaq, Saima; Wojczynski, Mary K; Lenzini, Petra; Nolte, Ilja M; Sparsø, Thomas; Schupf, Nicole; Christensen, Kaare; Perls, Thomas T; Newman, Anne B; Werge, Thomas; Snieder, Harold; Spector, Timothy D; Chambers, John C; Koskinen, Seppo; Melbye, Mads; Raitakari, Olli T; Lehtimäki, Terho; Tobin, Martin D; Wain, Louise V; Sinisalo, Juha; Peters, Annette; Meitinger, Thomas; Martin, Nicholas G; Wray, Naomi R; Montgomery, Grant W; Medland, Sarah E; Swertz, Morris A; Vartiainen, Erkki; Borodulin, Katja; Männistö, Satu; Murray, Anna; Bochud, Murielle; Jacquemont, Sébastien; Rivadeneira, Fernando; Hansen, Thomas F; Oldehinkel, Albertine J; Mangino, Massimo; Province, Michael A; Deloukas, Panos; Kooner, Jaspal S; Freathy, Rachel M; Pennell, Craig; Feenstra, Bjarke; Strachan, David P; Lettre, Guillaume; Hirschhorn, Joel; Cusi, Daniele; Heid, Iris M; Hayward, Caroline; Männik, Katrin; Beckmann, Jacques S; Loos, Ruth J F; Nyholt, Dale R; Metspalu, Andres; Eriksson, Johan G; Weedon, Michael N; Salomaa, Veikko; Franke, Lude; Reymond, Alexandre; Frayling, Timothy M; Kutalik, Zoltán

2017-01-01

There are few examples of robust associations between rare copy number variants (CNVs) and complex continuous human traits. Here we present a large-scale CNV association meta-analysis on anthropometric traits in up to 191,161 adult samples from 26 cohorts. The study reveals five CNV associations at

A Meta-Analysis of the Predictors of Cyberbullying Perpetration and Victimization

Science.gov (United States)

Guo, Siying

2016-01-01

Previous studies so far have investigated various aspects of cyberbullying. Using meta-analytic approaches, the study was primarily to determine the target factors predicting individuals' perpetration and victimization in cyberbullying. A meta-analysis of 77 studies containing 418 primary effect sizes was conducted to exam the relative magnitude…

Diagnostic value of WIF1 methylation for colorectal cancer: a meta-analysis

Science.gov (United States)

Chen, Min; Huang, Tianyi; Chen, Yuehong; Ji, Huihui; Pan, Ranran; Wang, Tiangong; Jiang, Danjie; Chen, Yanfei; Yang, Yong; Duan, Shiwei

2018-01-01

As a common antagonist of Wnt/β-catenin signaling, Wnt inhibitory factor 1 (WIF1) plays an important role in the tumor progression. The aim of our meta-analysis was to summarize the diagnostic value of WIF1 methylation in colorectal cancer (CRC). Eligible studies were retrieved by a systemic search among PubMed, Embase, CNKI, and Wanfang literature databases. The diagnostic value of WIF1 methylation for CRC was assessed by the summary receiver operating characteristics (SROC) test. Our meta-analysis of 12 studies between 1420 CRC samples and 946 control samples showed that WIF1 hypermethylation was significantly associated with CRC (P < 0.001, OR = 30.10, 95% CI = 19.48-46.50). WIF1 hypermethylation, as a diagnostic biomarker for CRC, has a pooled sensitivity of 0.40 (95% CI: 0.37-0.42), a pooled specificity of 0.95 (95% CI: 0.93-0.96), a pooled positive-likelihood ratio (PLR) of 8.65 (95% CI, 4.47-16.73), and a pooled negative-likelihood ratio (NLR) of 0.41 (95% CI, 0.30-0.55), a diagnostic odds ratio (DOR) of 26.86 (95% CI: 15.73-45.89), and an area under the curve (AUC) of 0.9115. In conclusion, our study established that WIF1 hypermethylation might be a promising diagnostic biomarker for CRC. PMID:29435185

Low circulating ghrelin levels in women with polycystic ovary syndrome: a systematic review and meta-analysis

Science.gov (United States)

Gao, Tian; Wu, Lang; Chang, Fuhou; Cao, Guifang

2016-01-01

Although numerous, human subject studies evaluating the relationship between circulating ghrelin levels and polycystic ovary syndrome (PCOS) risk have yielded inconsistent findings. We aimed to quantitatively assess the association by summarizing all available evidence from human subject studies. The PubMed and Web of Science databases were searched up to February 2015 for eligible studies. Studies were eligible if they reported circulating ghrelin levels in women with PCOS and healthy women controls. A fixed or random-effects model was used to pool risk estimations. Twenty studies including 894 PCOS patients and 574 controls were included in the meta-analysis. The studies had fair methodological quality. The pooling analysis of all available studies revealed that ghrelin levels were significantly lower in PCOS patients than in controls, with standardized mean difference of −0.40 (95% CI: −0.73, −0.08). The significant association persisted in many subgroup strata. However, the heterogeneity across studies was considerable and not eliminated in subgroup analyses. Meta-regression analysis further suggested that the heterogeneity might be relevant to variability in study location, PCOS relevant factors like HOMA-IR ratio, as well as other factors not assessed. In conclusion, our meta-analysis suggested that ghrelin levels were significantly lower in PCOS patients than in controls. Further studies with large sample sizes are warranted to replicate our findings. PMID:26607017

Comparison of sputum collection methods for tuberculosis diagnosis: a systematic review and pairwise and network meta-analysis.

Science.gov (United States)

Datta, Sumona; Shah, Lena; Gilman, Robert H; Evans, Carlton A

2017-08-01

The performance of laboratory tests to diagnose pulmonary tuberculosis is dependent on the quality of the sputum sample tested. The relative merits of sputum collection methods to improve tuberculosis diagnosis are poorly characterised. We therefore aimed to investigate the effects of sputum collection methods on tuberculosis diagnosis. We did a systematic review and meta-analysis to investigate whether non-invasive sputum collection methods in people aged at least 12 years improve the diagnostic performance of laboratory testing for pulmonary tuberculosis. We searched PubMed, Google Scholar, ProQuest, Web of Science, CINAHL, and Embase up to April 14, 2017, to identify relevant experimental, case-control, or cohort studies. We analysed data by pairwise meta-analyses with a random-effects model and by network meta-analysis. All diagnostic performance data were calculated at the sputum-sample level, except where authors only reported data at the individual patient-level. Heterogeneity was assessed, with potential causes identified by logistic meta-regression. We identified 23 eligible studies published between 1959 and 2017, involving 8967 participants who provided 19 252 sputum samples. Brief, on-demand spot sputum collection was the main reference standard. Pooled sputum collection increased tuberculosis diagnosis by microscopy (odds ratio [OR] 1·6, 95% CI 1·3-1·9, pmeta-analysis confirmed these findings, and revealed that both pooled and instructed spot sputum collections were similarly effective techniques for increasing the diagnostic performance of microscopy. Tuberculosis diagnoses were substantially increased by either pooled collection or by providing instruction on how to produce a sputum sample taken at any time of the day. Both interventions had a similar effect to that reported for the introduction of new, expensive laboratory tests, and therefore warrant further exploration in the drive to end the global tuberculosis epidemic. Wellcome Trust

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.

Meta-analysis, Simpson's paradox, and the number needed to treat

Directory of Open Access Journals (Sweden)

Deeks Jonathan J

2002-01-01

Full Text Available Abstract Background There is debate concerning methods for calculating numbers needed to treat (NNT from results of systematic reviews. Methods We investigate the susceptibility to bias for alternative methods for calculating NNTs through illustrative examples and mathematical theory. Results Two competing methods have been recommended: one method involves calculating the NNT from meta-analytical estimates, the other by treating the data as if it all arose from a single trial. The 'treat-as-one-trial' method was found to be susceptible to bias when there were imbalances between groups within one or more trials in the meta-analysis (Simpson's paradox. Calculation of NNTs from meta-analytical estimates is not prone to the same bias. The method of calculating the NNT from a meta-analysis depends on the treatment effect used. When relative measures of treatment effect are used the estimates of NNTs can be tailored to the level of baseline risk. Conclusions The treat-as-one-trial method of calculating numbers needed to treat should not be used as it is prone to bias. Analysts should always report the method they use to compute estimates to enable readers to judge whether it is appropriate.

The prevalence of food allergy: a meta-analysis

NARCIS (Netherlands)

Rona, Roberto J.; Keil, Thomas; Summers, Colin; Gislason, David; Zuidmeer, Laurian; Sodergren, Eva; Sigurdardottir, Sigurveig T.; Lindner, Titia; Goldhahn, Klaus; Dahlstrom, Jorgen; McBride, Doreen; Madsen, Charlotte

2007-01-01

There is uncertainty about the prevalence of food allergy in communities. To assess the prevalence of food allergy by performing a meta-analysis according to the method of assessment used. The foods assessed were cow's milk, hen's egg, peanut, fish, shellfish, and an overall estimate of food

Automatic imitation: A meta-analysis.

Science.gov (United States)

Cracco, Emiel; Bardi, Lara; Desmet, Charlotte; Genschow, Oliver; Rigoni, Davide; De Coster, Lize; Radkova, Ina; Deschrijver, Eliane; Brass, Marcel

2018-05-01

Automatic imitation is the finding that movement execution is facilitated by compatible and impeded by incompatible observed movements. In the past 15 years, automatic imitation has been studied to understand the relation between perception and action in social interaction. Although research on this topic started in cognitive science, interest quickly spread to related disciplines such as social psychology, clinical psychology, and neuroscience. However, important theoretical questions have remained unanswered. Therefore, in the present meta-analysis, we evaluated seven key questions on automatic imitation. The results, based on 161 studies containing 226 experiments, revealed an overall effect size of g z = 0.95, 95% CI [0.88, 1.02]. Moderator analyses identified automatic imitation as a flexible, largely automatic process that is driven by movement and effector compatibility, but is also influenced by spatial compatibility. Automatic imitation was found to be stronger for forced choice tasks than for simple response tasks, for human agents than for nonhuman agents, and for goalless actions than for goal-directed actions. However, it was not modulated by more subtle factors such as animacy beliefs, motion profiles, or visual perspective. Finally, there was no evidence for a relation between automatic imitation and either empathy or autism. Among other things, these findings point toward actor-imitator similarity as a crucial modulator of automatic imitation and challenge the view that imitative tendencies are an indicator of social functioning. The current meta-analysis has important theoretical implications and sheds light on longstanding controversies in the literature on automatic imitation and related domains. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

A Meta-Analysis on Antecedents and Outcomes of Detachment from Work.

Science.gov (United States)

Wendsche, Johannes; Lohmann-Haislah, Andrea

2016-01-01

Detachment from work has been proposed as an important non-work experience helping employees to recover from work demands. This meta-analysis (86 publications, k = 91 independent study samples, N = 38,124 employees) examined core antecedents and outcomes of detachment in employee samples. With regard to outcomes, results indicated average positive correlations between detachment and self-reported mental (i.e., less exhaustion, higher life satisfaction, more well-being, better sleep) and physical (i.e., lower physical discomfort) health, state well-being (i.e., less fatigue, higher positive affect, more intensive state of recovery), and task performance (small to medium sized effects). However, average relationships between detachment and physiological stress indicators and work motivation were not significant while associations with contextual performance and creativity were significant, but negative. Concerning work characteristics, as expected, job demands were negatively related and job resources were positively related to detachment (small sized effects). Further, analyses revealed that person characteristics such as negative affectivity/neuroticism (small sized effect) and heavy work investment (medium sized effect) were negatively related to detachment whereas detachment and demographic variables (i.e., age and gender) were not related. Moreover, we found a medium sized average negative relationship between engagement in work-related activities during non-work time and detachment. For most of the examined relationships heterogeneity of effect sizes was moderate to high. We identified study design, samples' gender distribution, and affective valence of work-related thoughts as moderators for some of these aforementioned relationships. The results of this meta-analysis point to detachment as a non-work (recovery) experience that is influenced by work-related and personal characteristics which in turn is relevant for a range of employee outcomes.

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…

The Trans-Contextual Model of Autonomous Motivation in Education: Conceptual and Empirical Issues and Meta-Analysis.

Science.gov (United States)

Hagger, Martin S; Chatzisarantis, Nikos L D

2016-06-01

The trans-contextual model outlines the processes by which autonomous motivation toward activities in a physical education context predicts autonomous motivation toward physical activity outside of school, and beliefs about, intentions toward, and actual engagement in, out-of-school physical activity. In the present article, we clarify the fundamental propositions of the model and resolve some outstanding conceptual issues, including its generalizability across multiple educational domains, criteria for its rejection or failed replication, the role of belief-based antecedents of intentions, and the causal ordering of its constructs. We also evaluate the consistency of model relationships in previous tests of the model using path-analytic meta-analysis. The analysis supported model hypotheses but identified substantial heterogeneity in the hypothesized relationships across studies unattributed to sampling and measurement error. Based on our meta-analysis, future research needs to provide further replications of the model in diverse educational settings beyond physical education and test model hypotheses using experimental methods.

A Meta-Analysis of the Relation between Creative Self-Efficacy and Different Creativity Measurements

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Haase, Jennifer; Hoff, Eva V.; Hanel, Paul H. P.; Innes-Ker, Åse

2018-01-01

This meta-analysis investigated the relations between creative self-efficacy (CSE) and creativity measures and hypothesized that self-assessed questionnaires would have a different relation to self-efficacy beliefs compared to other creativity tests. The meta-analysis synthesized 60 effect sizes from 41 papers (overall N = 17226). Taken as a…

Prevalence of premenstrual syndrome in Iran: A systematic review and meta-analysis

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Mehdi Ranjbaran

2017-11-01

Full Text Available Background: Premenstrual syndrome (PMS is a common disorder characterized by physical, mental and behavioral changes in the luteal phase of the menstrual cycle in the reproductive age women. Objective: The present study aimed to determine the overall prevalence of PMS in Iran by a systematic review and meta-analysis study. Materials and Methods: In this systematic review and meta-analysis, we searched international databases included ISI Web of Knowledge, PubMed/Medline, Scopus, Google Scholar, and also local databases including Iranmedex, Scientific Information Database, and Magiran for articles in English and Persian language published up to September 2016. We carried out data analysis with Stata version 11. We examined heterogeneity in the results of studies through I2 statistics and Chi-square based Q test. Also, we investigated the effects of potential heterogeneity factors in the prevalence of PMS by meta-regression. Results: We studied a total of 9147 reproductive-age women from 24 articles which entered to meta-analysis. Based on the result of random effect model, we estimated the overall prevalence of PMS 70.8% [95% CI: 63.8-77.7]. The results of subgroup analysis revealed that prevalence of PMS was 80.4% (95% CI; 66.9-93.9 among high school students, 68.9% (95% CI; 59.2-78.6 among university students, and 54.9% (95% CI; 51.6-58.2 in general population. Univariate meta-regression model showed that prevalence of PMS was decreased by increasing the age of subjects but this was not statistically significant (p=0.155. Conclusion: Our finding showed that PMS was prevalent in Iranian reproductive age women especially among high school students. More epidemiological research for determining factors that affect PMS prevalence seems essential.

The Effects of Choice on Intrinsic Motivation and Related Outcomes: A Meta-Analysis of Research Findings

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Patall, Erika A.; Cooper, Harris; Robinson, Jorgianne Civey

2008-01-01

A meta-analysis of 41 studies examined the effect of choice on intrinsic motivation and related outcomes in a variety of settings with both child and adult samples. Results indicated that providing choice enhanced intrinsic motivation, effort, task performance, and perceived competence, among other outcomes. Moderator tests revealed the effect…

Meta-analysis of lipid-traits in Hispanics identifies novel loci, population-specific effects, and tissue-specific enrichment of eQTLs

NARCIS (Netherlands)

Below, Jennifer E.; Parra, Esteban J.; Gamazon, Eric R.; Torres, Jason; Krithika, S.; Candille, Sophie; Lu, Yingchang; Manichakul, Ani; Peralta-Romero, Jesus; Duan, Qing; Li, Yun; Morris, Andrew P.; Gottesman, Omri; Bottinger, Erwin; Wang, Xin-Qun; Taylor, Kent D.; Ida Chen, Y.-D.; Rotter, Jerome I.; Rich, Stephen S.; Loos, Ruth J. F.; Tang, Hua; Cox, Nancy J.; Cruz, Miguel; Hanis, Craig L.; Valladares-Salgado, Adan

2016-01-01

We performed genome-wide meta-analysis of lipid traits on three samples of Mexican and Mexican American ancestry comprising 4,383 individuals, and followed up significant and highly suggestive associations in three additional Hispanic samples comprising 7,876 individuals. Genome-wide significant

Meta-Transcriptomic Analysis of a Chromate-Reducing Aquifer Microbial Community

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Beller, H. R.; Brodie, E. L.; Han, R.; Karaoz, U.

2010-12-01

A major challenge for microbial ecology that has become more tractable in the advent of new molecular techniques is characterizing gene expression in complex microbial communities. We are using meta-transcriptomic analysis to characterize functional changes in an aquifer-derived, chromate-reducing microbial community as it transitions through various electron-accepting conditions. We inoculated anaerobic microcosms with groundwater from the Cr-contaminated Hanford 100H site and supplemented them with lactate and electron acceptors present at the site, namely, nitrate, sulfate, and Fe(III). The microcosms progressed successively through various electron-accepting conditions (e.g., denitrifying, sulfate-reducing, and ferric iron-reducing conditions, as well as nitrate-dependent, chemolithotrophic Fe(II)-oxidizing conditions). Cr(VI) was rapidly reduced initially and again upon further Cr(VI) amendments. Extensive geochemical sampling and analysis (e.g., lactate, acetate, chloride, nitrate, nitrite, sulfate, dissolved Cr(VI), total Fe(II)), RNA/DNA harvesting, and PhyloChip analyses were conducted. Methods were developed for removal of rRNA from total RNA in preparation for meta-transcriptome sequencing. To date, samples representing denitrifying and fermentative/sulfate-reducing conditions have been sequenced using 454 Titanium technology. Of the non-rRNA related reads for the denitrifying sample (which was also actively reducing chromate), ca. 8% were associated with denitrification and ca. 0.9% were associated with chromate resistance/transport, in contrast to the fermentative/sulfate-reducing sample (in which chromate had already been reduced), which had zero reads associated with either of these categories but many predicted proteins associated with sulfate-reducing bacteria. We observed sequences for key functional transcripts that were unique at the nucleotide level compared to the GenBank non-redundant database [such as L-lactate dehydrogenase (iron

A double-loop adaptive sampling approach for sensitivity-free dynamic reliability analysis

International Nuclear Information System (INIS)

Wang, Zequn; Wang, Pingfeng

2015-01-01

Dynamic reliability measures reliability of an engineered system considering time-variant operation condition and component deterioration. Due to high computational costs, conducting dynamic reliability analysis at an early system design stage remains challenging. This paper presents a confidence-based meta-modeling approach, referred to as double-loop adaptive sampling (DLAS), for efficient sensitivity-free dynamic reliability analysis. The DLAS builds a Gaussian process (GP) model sequentially to approximate extreme system responses over time, so that Monte Carlo simulation (MCS) can be employed directly to estimate dynamic reliability. A generic confidence measure is developed to evaluate the accuracy of dynamic reliability estimation while using the MCS approach based on developed GP models. A double-loop adaptive sampling scheme is developed to efficiently update the GP model in a sequential manner, by considering system input variables and time concurrently in two sampling loops. The model updating process using the developed sampling scheme can be terminated once the user defined confidence target is satisfied. The developed DLAS approach eliminates computationally expensive sensitivity analysis process, thus substantially improves the efficiency of dynamic reliability analysis. Three case studies are used to demonstrate the efficacy of DLAS for dynamic reliability analysis. - Highlights: • Developed a novel adaptive sampling approach for dynamic reliability analysis. • POD Developed a new metric to quantify the accuracy of dynamic reliability estimation. • Developed a new sequential sampling scheme to efficiently update surrogate models. • Three case studies were used to demonstrate the efficacy of the new approach. • Case study results showed substantially enhanced efficiency with high accuracy

The association between Selenium and Prostate Cancer: a Systematic Review and Meta-Analysis

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Sayehmiri, Kourosh; Azami, Milad; Mohammadi, Younes; Soleymani, Ali; Tardeh, Zainab

2018-06-25

Background: Evidence of relationship between selenium and prostate cancer has been inconsistent. The present metaanalysis was conducted to determine relationship between selenium and prostate cancer. Methods: A systematic review and meta-analysis was carried out using preferred reporting items for systematic reviews and meta-analysis (PRISMA). We searched PubMed, Scopus, Web of Science, ScienceDirect, Embase, CINAHL, Cochrane Library, EBSCO and Google scholar search engines and the reference lists of the retrieved papers for relevant data, without any limitation regarding language or time until 2016. Heterogeneity among studies was evaluated using Q test and I2 Index. Finally, a random effects model was used for combining results using STATA software version 11.1. P<0.05 was considered significant. Results: Thirty-eight studies including 36,419 cases and 105,293 controls were included in the final analysis. The pooled relative risk (RR) of relation between selenium and prostate cancer was 0.86 (95% Confidence Interval [CI]:0.78-0.94). Sub-group analyses based on case-control, cohort, and RCT studies gave values of 0.89 (95% CI: 0.80-1.00), 0.77 (95% CI: 0.52-1.14) and 0.90 (95% CI: 0.74-1.09), respectively. RRs based on serum, plasma and nail samples were 0.69 (95% CI: 0.51-0.95), 0.85 (95% CI: 0.61-1.17), 0.66 (95% CI: 0.41-1.05), respectively. According to 10 studies, investigated the relation between advanced prostate cancer and selenium in which the RR was 0.67 (95% CI: 0.52-0.87). Conclusions: This meta-analysis indicated that selenium most probably has a protective role against development of prostate cancer and its progression to advanced stages. Therefore, selenium supplementation can be proposed for prevention of prostate cancer. Creative Commons Attribution License

Maternal education and breastfeeding practices in China: A systematic review and meta-analysis.

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Zhao, Jian; Zhao, Yun; Du, Mengran; Binns, Colin W; Lee, Andy H

2017-07-01

to examine the association between maternal education and breastfeeding prevalence in China. a systematic review and meta-analysis was conducted based on the literature of observational studies retrieved from electronic databases of CNKI, Medline, Embase, CINHAL, ProQuest and Science Direct. Maternal education was recoded into two binary categorical variables using different cut-off points. Both fixed and random effect models were used to estimate the pooled association between maternal education and breastfeeding prevalence in China. Visual inspection of Galbraith plot for heterogeneity detection, sensitivity analysis and publication bias test were performed. a total of 31 studies were included in the systematic review, and 15 and 26 studies were suitable for meta-analysis in terms of two different cutoff points of maternal education respectively. In the group using 6-year education cut-off (Group 1), the odds of breastfeeding was 10% (pooled OR=0.90, 95% CI: 0.83, 0.97) lower in mothers who had been educated for 'more than 6 years' compared to mothers with '6 years or less' education. In the group using 12-year education cut-off (Group 2), the odds of breastfeeding was 9% (pooled OR=0.91, 95% CI: 0.86, 0.96) lower in mothers who had 'more than 12 years' education compared to mothers who attained '12 years or less' education. There was substantial heterogeneity across the studies in both groups. Through meta-regression analysis, sample size of studies was detected contributing to the heterogeneity in Group 1; however none of study level factors were found to be a source of heterogeneity in Group 2. in the Chinese culture and employment environment, mothers who have attained a higher level of education are less likely to breastfeed their babies compared to mothers with lower education levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

Feature-Space Clustering for fMRI Meta-Analysis

DEFF Research Database (Denmark)

Goutte, Cyril; Hansen, Lars Kai; Liptrot, Mathew G.

2001-01-01

MRI sequences containing several hundreds of images, it is sometimes necessary to invoke feature extraction to reduce the dimensionality of the data space. A second interesting application is in the meta-analysis of fMRI experiment, where features are obtained from a possibly large number of single......-voxel analyses. In particular this allows the checking of the differences and agreements between different methods of analysis. Both approaches are illustrated on a fMRI data set involving visual stimulation, and we show that the feature space clustering approach yields nontrivial results and, in particular......, shows interesting differences between individual voxel analysis performed with traditional methods. © 2001 Wiley-Liss, Inc....

Multivariate Meta-Analysis of Genetic Association Studies: A Simulation Study.

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Binod Neupane

Full Text Available In a meta-analysis with multiple end points of interests that are correlated between or within studies, multivariate approach to meta-analysis has a potential to produce more precise estimates of effects by exploiting the correlation structure between end points. However, under random-effects assumption the multivariate estimation is more complex (as it involves estimation of more parameters simultaneously than univariate estimation, and sometimes can produce unrealistic parameter estimates. Usefulness of multivariate approach to meta-analysis of the effects of a genetic variant on two or more correlated traits is not well understood in the area of genetic association studies. In such studies, genetic variants are expected to roughly maintain Hardy-Weinberg equilibrium within studies, and also their effects on complex traits are generally very small to modest and could be heterogeneous across studies for genuine reasons. We carried out extensive simulation to explore the comparative performance of multivariate approach with most commonly used univariate inverse-variance weighted approach under random-effects assumption in various realistic meta-analytic scenarios of genetic association studies of correlated end points. We evaluated the performance with respect to relative mean bias percentage, and root mean square error (RMSE of the estimate and coverage probability of corresponding 95% confidence interval of the effect for each end point. Our simulation results suggest that multivariate approach performs similarly or better than univariate method when correlations between end points within or between studies are at least moderate and between-study variation is similar or larger than average within-study variation for meta-analyses of 10 or more genetic studies. Multivariate approach produces estimates with smaller bias and RMSE especially for the end point that has randomly or informatively missing summary data in some individual studies, when

Does anaesthesia with nitrous oxide affect mortality or cardiovascular morbidity? A systematic review with meta-analysis and trial sequential analysis.

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Imberger, G; Orr, A; Thorlund, K; Wetterslev, J; Myles, P; Møller, A M

2014-03-01

The role of nitrous oxide in modern anaesthetic practice is contentious. One concern is that exposure to nitrous oxide may increase the risk of cardiovascular complications. ENIGMA II is a large randomized clinical trial currently underway which is investigating nitrous oxide and cardiovascular complications. Before the completion of this trial, we performed a systematic review and meta-analysis, using Cochrane methodology, on the outcomes that make up the composite primary outcome. We used conventional meta-analysis and trial sequential analysis (TSA). We reviewed 8282 abstracts and selected 138 that fulfilled our criteria for study type, population, and intervention. We attempted to contact the authors of all the selected publications to check for unpublished outcome data. Thirteen trials had outcome data eligible for our outcomes. We assessed three of these trials as having a low risk of bias. Using conventional meta-analysis, the relative risk of short-term mortality in the nitrous oxide group was 1.38 [95% confidence interval (CI) 0.22-8.71] and the relative risk of long-term mortality in the nitrous oxide group was 0.94 (95% CI 0.80-1.10). In both cases, TSA demonstrated that the data were far too sparse to make any conclusions. There were insufficient data to perform meta-analysis for stroke, myocardial infarct, pulmonary embolus, or cardiac arrest. This systematic review demonstrated that we currently do not have robust evidence for how nitrous oxide used as part of general anaesthesia affects mortality and cardiovascular complications.

Veterinary homeopathy: meta-analysis of randomised placebo-controlled trials.

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Mathie, Robert T; Clausen, Jürgen

2015-01-01

Meta-analysis of randomised controlled trials (RCTs) of veterinary homeopathy has not previously been undertaken. For all medical conditions and species collectively, we tested the hypothesis that the outcome of homeopathic intervention (treatment and/or prophylaxis, individualised and/or non-individualised) is distinguishable from corresponding intervention using placebos. All facets of the review, including literature search strategy, study eligibility, data extraction and assessment of risk of bias, were described in an earlier paper. A trial was judged to comprise reliable evidence if its risk of bias was low or was unclear in specific domains of assessment. Effect size was reported as odds ratio (OR). A trial was judged free of vested interest if it was not funded by a homeopathic pharmacy. Meta-analysis was conducted using the random-effects model, with hypothesis-driven sensitivity analysis based on risk of bias. Nine of 15 trials with extractable data displayed high risk of bias; low or unclear risk of bias was attributed to each of the remaining six trials, only two of which comprised reliable evidence without overt vested interest. For all N = 15 trials, pooled OR = 1.69 [95% confidence interval (CI), 1.12 to 2.56]; P = 0.01. For the N = 2 trials with suitably reliable evidence, pooled OR = 2.62 [95% CI, 1.13 to 6.05]; P = 0.02). Meta-analysis provides some very limited evidence that clinical intervention in animals using homeopathic medicines is distinguishable from corresponding intervention using placebos. The low number and quality of the trials hinders a more decisive conclusion. Copyright © 2014 The Faculty of Homeopathy. Published by Elsevier Ltd. All rights reserved.

Digital Games, Design, and Learning: A Systematic Review and Meta-Analysis

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Clark, Douglas B.; Tanner-Smith, Emily E.; Killingsworth, Stephen S.

2016-01-01

In this meta-analysis, we systematically reviewed research on digital games and learning for K-16 students. We synthesized comparisons of game versus nongame conditions (i.e., media comparisons) and comparisons of augmented games versus standard game designs (i.e., value-added comparisons). We used random-effects meta-regression models with robust…

Determining The Factors Affecting Fruit Hardness of Different Peach Types with Meta Analysis

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Hande Küçükönder

2014-09-01

Full Text Available The aim of this study is to determine the factor effective in determining the hardness of Caterina, Suidring, Royal Glory and Tirrenia peach types using meta analysis. In the study, the impact force (Fi and the contact time (tc were detected and the impulse values (I that are expressed as independent variable in the area under the curve were calculated in the measurements performed using the technique of a low-mass lateral impactor multiplicated with peach. Using the theory of elasticity, the independent variables were determined as Fmax (maximum impact force, contact time (tmax, Fmax/tmax, 1/tmax, 1/tmax2,5, Fmax/tmax 1.25 and Fmax2.5 parameters. The correlation coefficient values showing the relationship between these parameters and the dependent variable Magness-Taylor force (MT were calculated and were combined with meta-analysis by using the Hunter-Schmid and Fisher’s Z methods. The Cohen’s classification criterion was used in evaluating the resulting mean effect size (combined correlation value and in determining its direction. As a result of the meta-analysis, the mean effect size according to Hunter-Schmid method was found 0.436 (0.371-0.497 positively directed in 95% confidence interval, while it was found 0.468 (0.390-0.545 according to Fisher’s Z method. The effect sizes in both methods were determined “mid-level” according to the Cohen’s classification. When the significance level of the studies was analyzed with the Z test, all of the ones that taken into the meta analysis has been found statistically significant. As a result of the meta analysis in this study evaluating the relationship of peach types with the fruit hardness, the mean effect size has been found to reach “strong level”. Consequently, “maximum shock acceleration” was found to be a more effective factor comparing to the other factors in determining the the fruit hardness according to the results of meta analysis applied in both methods.

Babies and math: A meta-analysis of infants' simple arithmetic competence.

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Christodoulou, Joan; Lac, Andrew; Moore, David S

2017-08-01

Wynn's (1992) seminal research reported that infants looked longer at stimuli representing "incorrect" versus "correct" solutions of basic addition and subtraction problems and concluded that infants have innate arithmetical abilities. Since then, infancy researchers have attempted to replicate this effect, yielding mixed findings. The present meta-analysis aimed to systematically compile and synthesize all of the primary replications and extensions of Wynn (1992) that have been conducted to date. The synthesis included 12 studies consisting of 26 independent samples and 550 unique infants. The summary effect, computed using a random-effects model, was statistically significant, d = +0.34, p < .001, suggesting that the phenomenon Wynn originally reported is reliable. Five different tests of publication bias yielded mixed results, suggesting that while a moderate level of publication bias is probable, the summary effect would be positive even after accounting for this issue. Out of the 10 metamoderators tested, none were found to be significant, but most of the moderator subgroups were significantly different from a null effect. Although this meta-analysis provides support for Wynn's original findings, further research is warranted to understand the underlying mechanisms responsible for infants' visual preferences for "mathematically incorrect" test stimuli. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Survival after radiotherapy in gastric cancer: Systematic review and meta-analysis

International Nuclear Information System (INIS)

Valentini, Vincenzo; Cellini, Francesco; Minsky, Bruce D.; Mattiucci, Gian Carlo; Balducci, Mario; D'Agostino, Giuseppe; D'Angelo, Elisa; Dinapoli, Nicola; Nicolotti, Nicola; Valentini, Chiara; La Torre, Giuseppe

2009-01-01

Background and purpose: A systematic review and meta-analysis was performed to assess the impact of radiotherapy on both 3- and 5-year survival in patients with resectable gastric cancer. Methods: Randomized Clinical Trials (RCTs) in which radiotherapy, (preoperative, postoperative and/or intraoperative), was compared with surgery alone or surgery plus chemotherapy in resectable gastric cancer were identified by searching web-based databases and supplemented by manual examination of reference lists. Meta-analysis was performed using Risk Ratios (RRs). Random or fixed effects models were used to combine data. The methodological quality was evaluated by Chalmers' score. Results: Radiotherapy had a significant impact on 5-year survival. Using an intent to treat (ITT) and a Per Protocol (PP) analysis, the overall 5-year RR was 1.26 (95% CI: 1.08-1.48; NNT = 17) and 1.31 (95% CI: 1.04-1.66; NNT = 13), respectively. Although the quality of the studies was variable, the data were consistent and no clear publication bias was found. Conclusion: This meta-analysis showed a statistically significant 5-year survival benefit with the addition of radiotherapy in patients with resectable gastric cancer. Radiotherapy remains a standard component in the treatment of resectable gastric cancer and new RCTs need to address the impact of new conformal radiotherapy technologies.

Smoking and olfactory dysfunction: A systematic literature review and meta-analysis.

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Ajmani, Gaurav S; Suh, Helen H; Wroblewski, Kristen E; Pinto, Jayant M

2017-08-01

A systematic review and meta-analysis of the literature was undertaken, examining the association between tobacco smoking and olfactory function in humans, utilizing PubMed and Web of Science (1970-2015) as data sources. Systematic literature review and meta-analysis. This database review of studies of smoking and olfaction, with a focus on identifying high-quality studies (based on modified versions of the Newcastle-Ottawa Scale), used validated olfactory tests among the generally healthy population. We identified 11 studies meeting inclusion criteria. Of 10 cross-sectional studies, two were excluded from meta-analysis because the cohorts they studied were included in another article in the review. In meta-analysis, current smokers had substantially higher odds of olfactory dysfunction compared to never smokers (odds ratio [OR] = 1.59, 95% confidence interval [CI] = 1.37-1.85). In contrast, former smokers were found to have no difference in risk of impaired olfaction compared to never smokers (OR = 1.05, 95% CI = 0.91-1.21). The single longitudinal study reviewed found a trend toward increased risk of olfactory decline over time in ever smokers; this trend was stronger in current as compared to former smokers. Current smoking, but not former smoking, is associated with significantly increased risk of olfactory dysfunction, suggesting that the effects of smoking on olfaction may be reversible. Future studies that prospectively evaluate the impact of smoking cessation on improvement in olfactory function are warranted. N/A. Laryngoscope, 127:1753-1761, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Teaching tools in Evidence Based Practice: evaluation of reusable learning objects (RLOs for learning about Meta-analysis

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Wharrad Heather

2011-05-01

Full Text Available Abstract Background All healthcare students are taught the principles of evidence based practice on their courses. The ability to understand the procedures used in systematically reviewing evidence reported in studies, such as meta-analysis, are an important element of evidence based practice. Meta-analysis is a difficult statistical concept for healthcare students to understand yet it is an important technique used in systematic reviews to pool data from studies to look at combined effectiveness of treatments. In other areas of the healthcare curricula, by supplementing lectures, workbooks and workshops with pedagogically designed, multimedia learning objects (known as reusable learning objects or RLOs we have shown an improvement in students' perceived understanding in subjects they found difficult. In this study we describe the development and evaluation of two RLOs on meta-analysis. The RLOs supplement associated lectures and aim to improve students' understanding of meta-analysis in healthcare students. Methods Following a quality controlled design process two RLOs were developed and delivered to two cohorts of students, a Master in Public Health course and Postgraduate diploma in nursing course. Students' understanding of five key concepts of Meta-analysis were measured before and after a lecture and again after RLO use. RLOs were also evaluated for their educational value, learning support, media attributes and usability using closed and open questions. Results Students rated their understanding of meta-analysis as improved after a lecture and further improved after completing the RLOs (Wilcoxon paired test, p Conclusions Meta-analysis RLOs that are openly accessible and unrestricted by usernames and passwords provide flexible support for students who find the process of meta-analysis difficult.

Night Shift Work and Risk of Depression: Meta-analysis of Observational Studies.

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Lee, Aeyoung; Myung, Seung Kwon; Cho, Jung Jin; Jung, Yu Jin; Yoon, Jong Lull; Kim, Mee Young

2017-07-01

This study aimed to assess whether night shift work is associated with the risk of depression by using a meta-analysis of observational studies. We searched PubMed and EMBASE in August, 2016 to locate eligible studies and investigated the association between night shift work and the risk of depression, reporting outcome measures with adjusted odds ratios (ORs) or relative risks (RRs) and 95% confidence intervals (CIs). In the meta-analysis of a total of 11 observational studies with 9 cross-sectional study, 1 longitudinal study, and 1 cohort study, night shift work was significantly associated with an increased risk of depression (OR/RR, 1.43; 95% CI, 1.24-1.64; I² = 78.0%). Also, subgroup meta-analyses by gender, night shift work duration, type of occupation, continent, and type of publication showed that night shift work was consistently associated with the increased risk of depression. The current meta-analysis suggests that night shift work is associated with the increased risk of depression. However, further large prospective cohort studies are needed to confirm this association. © 2017 The Korean Academy of Medical Sciences.

Steep Delay Discounting and Addictive Behavior: A Meta-Analysis of Continuous Associations

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Amlung, Michael; Vedelago, Lana; Acker, John; Balodis, Iris; MacKillop, James

2016-01-01

Aims To synthesize continuous associations between delayed reward discounting (DRD) and both addiction severity and quantity-frequency (QF); to examine moderators of these relationships; and to investigate publication bias. Methods Meta-analysis of published studies examining continuous associations between DRD and addictive behaviors. Published, peer-reviewed studies on addictive behaviors (alcohol, tobacco, cannabis, stimulants, opiates, and gambling) were identified via PubMed, MEDLINE, and PsycInfo. Studies were restricted to DRD measures of monetary gains. Random effects meta-analysis was conducted using Pearson’s r as the effect size. Publication bias was evaluated using fail-safe N, Begg-Mazumdar and Egger’s tests, meta-regression of publication year and effect size, and imputation of missing studies. Results The primary meta-analysis revealed a small magnitude effect size that was highly significant (r = 0.14, p addictive behavior (p = 0.30) or DRD assessment (p = 0.90). Indices of publication bias suggested a modest impact of unpublished findings. Conclusions Delayed reward discounting is robustly associated with continuous measures of addiction severity and quantity-frequency. This relation is generally robust across type of addictive behavior and delayed reward discounting assessment modality. PMID:27450931

Protection from sunburn with beta-Carotene--a meta-analysis.

Science.gov (United States)

Köpcke, Wolfgang; Krutmann, Jean

2008-01-01

Nutritional protection against skin damage from sunlight is increasingly advocated to the general public, but its effectiveness is controversial. In this meta-analysis, we have systematically reviewed the existing literature on human supplementation studies on dietary protection against sunburn by beta-carotene. A review of literature until June 2007 was performed in PubMed, ISI Web of Science and EBM Cochrane library and identified a total of seven studies which evaluated the effectiveness of beta-carotene in protection against sunburn. Data were abstracted from these studies by means of a standardized data collection protocol. The subsequent meta-analysis showed that (1) beta-carotene supplementation protects against sunburn and (2) the study duration had a significant influence on the effected size. Regression plot analysis revealed that protection required a minimum of 10 weeks of supplementation with a mean increase of the protective effect of 0.5 standard deviations with every additional month of supplementation. Thus, dietary supplementation of humans with beta-carotene provides protection against sunburn in a time-dependent manner.

Risk for Asthma in Offspring of Asthmatic Mothers versus Fathers: A Meta-Analysis

DEFF Research Database (Denmark)

Lim, R.H.; Kobzik, L.; Dahl, Morten

2010-01-01

Background: Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude of the "mate......Background: Many human epidemiologic studies demonstrate that maternal asthma confers greater risk of asthma to offspring than does paternal disease. However, a handful have shown the opposite. Given this disparity, a meta-analysis is necessary to determine the veracity and magnitude...... of the "maternal effect.'' Methodology/Principal Findings: We screened the medical literature from 1966 to 2009 and performed a meta-analysis to compare the effect of maternal asthma vs. paternal asthma on offspring asthma susceptibility. Aggregating data from 33 studies, the odds ratio for asthma in children...

A Karnaugh map based approach towards systemic reviews and meta-analysis.

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Hassan, Abdul Wahab; Hassan, Ahmad Kamal

2016-01-01

Studying meta-analysis and systemic reviews since long had helped us conclude numerous parallel or conflicting studies. Existing studies are presented in tabulated forms which contain appropriate information for specific cases yet it is difficult to visualize. On meta-analysis of data, this can lead to absorption and subsumption errors henceforth having undesirable potential of consecutive misunderstandings in social and operational methodologies. The purpose of this study is to investigate an alternate forum for meta-data presentation that relies on humans' strong pictorial perception capability. Analysis of big-data is assumed to be a complex and daunting task often reserved on the computational powers of machines yet there exist mapping tools which can analyze such data in a hand-handled manner. Data analysis on such scale can benefit from the use of statistical tools like Karnaugh maps where all studies can be put together on a graph based mapping. Such a formulation can lead to more control in observing patterns of research community and analyzing further for uncertainty and reliability metrics. We present a methodological process of converting a well-established study in Health care to its equaling binary representation followed by furnishing values on to a Karnaugh Map. The data used for the studies presented herein is from Burns et al (J Publ Health 34(1):138-148, 2011) consisting of retrospectively collected data sets from various studies on clinical coding data accuracy. Using a customized filtration process, a total of 25 studies were selected for review with no, partial, or complete knowledge of six independent variables thus forming 64 independent cells on a Karnaugh map. The study concluded that this pictorial graphing as expected had helped in simplifying the overview of meta-analysis and systemic reviews.

Meta-analysis of TNF 308 G/A polymorphism and type 2 diabetes mellitus.

Directory of Open Access Journals (Sweden)

Ren-Nan Feng

Full Text Available BACKGROUND AND OBJECTIVES: Many investigations have focused the association between TNF 308 G/A polymorphism and risk for type 2 diabetes mellitus (T2DM. However, the sample sizes of most of the studies were small. The aim of this study is to evaluate the precise association between this variant and risk for T2DM in a large-scale meta-analysis. METHODS: All publications were searched on the association between TNF 308 G/A polymorphism and T2DM. The key words were as follows: diabetes, tumor necrosis factor and polymorphism/variant/genotype. This meta-analysis was assessed by Review manager 5.0. RESULTS: There were 18 studies identified. The odds ratios (ORs and 95% confidence intervals (CI for GA+AA versus GG genotype of TNF 308 G/A polymorphism were 1.03 (0.95-1.12, 1.03 (0.94-1.13 and 1.03 (0.78-1.36 in overall, Caucasian and Asian populations, respectively. The sensitivity analysis further strengthened the validity of this association. No publication bias or heterogeneity was observed in this study. CONCLUSION: In summary, there was no significant association detected between the TNF 308 G/A polymorphism and risk for T2DM.

An update on psoriasis and metabolic syndrome: A meta-analysis of observational studies.

Directory of Open Access Journals (Sweden)

Sanminder Singh

Full Text Available The relationship between psoriasis and metabolic syndrome is not well understood. Though multiple epidemiologic studies have suggested a link between psoriasis and metabolic syndrome, there is a lack of a comprehensive meta-analysis synthesizing the results of all available observational studies to date. In this meta-analysis, we examined global data on the relationship between psoriasis and odds of metabolic syndrome by searching for studies published between 1946-2016. Specifically, we analyzed the results from 35 observational studies from 20 countries with 1,450,188 total participants, of which 46,714 were psoriasis patients. The pooled odds ratio based on random effects analysis was 2.14 (95% CI 1.84-2.48. Publication bias was present, as evidenced by an Egger test and graphical visualization through a funnel plot (p = 0.001. Based on this comprehensive meta-analysis, psoriasis patients have higher odds of having metabolic syndrome when compared with the general population.

Neutrophil/lymphocyte ratio and platelet/lymphocyte ratio in mood disorders: A meta-analysis.

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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.

Meta-analysis of short- and mid-term efficacy of ketamine in unipolar and bipolar depression.

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Romeo, Bruno; Choucha, Walid; Fossati, Philippe; Rotge, Jean-Yves

2015-12-15

Among treatments currently assessed in major depression, ketamine, has been proposed of great interest, especially because of its very rapid action. However, the time-course of the antidepressive action of ketamine remained unclear. In the present meta-analysis, we provided a clear and objective view regarding the putative antidepressive effect of ketamine and its time-course. We searched the MEDLINE and PsycINFO databases through December 2013, without limits on year of publication, using the key words ketamine and synonyms for mood disorder or episode. Six randomized, double-blind and placebo-controlled trials of ketamine in major depression (n=103 patients) were thus identified. Authors were contacted and they all provided original data necessary for this meta-analysis. Standardized mean differences (SMD) were calculated between the depression scores in ketamine and placebo groups at days 1, 2, 3-4, 7 and 14. Ketamine showed an overall antidepressive efficacy from day 1 to day 7. However, the maintenance of its efficacy over time failed to reach significance in bipolar depression after day 3-4. Significant SMDs were not explained by demographic or clinical characteristics of included samples. The present meta-analysis provides a high level of evidence that ketamine has a rapid antidepressive action during one week, especially in unipolar disorder. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Personality and Parkinson's disease: A meta-analysis.

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Santangelo, Gabriella; Garramone, Federica; Baiano, Chiara; D'Iorio, Alfonsina; Piscopo, Fausta; Raimo, Simona; Vitale, Carmine

2018-04-01

Personality changes are considered pre-motor features of Parkinson's disease (PD). Cross-sectional studies revealed that PD patients were more introvert, apprehensive, and cautious than healthy subjects (HS), whereas other studies failed to disclose these behavioural traits. Some studies found mixed results concerning Novelty Seeking (NS) and Harm Avoidance (HA) profiles in PD patients. To better clarify the personality profile in PD we performed a meta-analysis on studies exploring such topic according to both Cloninger's Psychobiological Model (PM) and Big Five Model (BFM) METHODS: The meta-analysis included 17 studies evaluating the personality in PD patients compared with HS. The outcomes were the dimensions of the temperament and character of the PM and personality traits of BFM. Effect sizes from data reported in the primary studies were computed using Hedges'g unbiased approach. Heterogeneity among the studies and publication bias were assessed. Meta-regressions were conducted with age at evaluation, gender, schooling, and type of personality trait tools as moderators. As for PM, PD patients scored higher on HA and lower on NS than HS. No difference was found on Reward Dependence, Perseverance/Persistence and on character level. As for BFM, higher levels of Neuroticism, but lower levels of Openness and Extraversion were associated with PD. The personality profile in PD is characterized by high Neuroticism and HA, and by low Openness, Extraversion and NS. The personality profile delineated in the present study on PD patients seems to reflect the premorbid one and might contribute to development and persistence of affective disorders. Copyright © 2018 Elsevier Ltd. All rights reserved.

Appealing to fear: A Meta-Analysis of Fear Appeal Effectiveness and Theories

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Tannenbaum, Melanie B.; Hepler, Justin; Zimmerman, Rick S.; Saul, Lindsey; Jacobs, Samantha; Wilson, Kristina; Albarracin, Dolores

2018-01-01

Fear appeals are a polarizing issue, with proponents confident in their efficacy and opponents confident that they backfire. We present the results of a comprehensive meta-analysis investigating fear appeals’ effectiveness for influencing attitudes, intentions, and behaviors. We tested predictions from a large number of theories, the majority of which have never been tested meta-analytically until now. Studies were included if they contained a treatment group exposed to a fear appeal, a valid comparison group, a manipulation of depicted fear, a measure of attitudes, intentions, or behaviors concerning the targeted risk or recommended solution, and adequate statistics to calculate effect sizes. The meta-analysis included 127 papers (9% unpublished) yielding 248 independent samples (NTotal = 27,372) collected from diverse populations. Results showed a positive effect of fear appeals on attitudes, intentions, and behaviors, with the average effect on a composite index being random-effects d¯ = 0.29. Moderation analyses based on prominent fear appeal theories showed that the effectiveness of fear appeals increased when the message included efficacy statements, depicted high susceptibility and severity, recommended one-time only (vs. repeated) behaviors, and targeted audiences that included a larger percentage of female message recipients. Overall, we conclude that (a) fear appeals are effective at positively influencing attitude, intentions, and behaviors, (b) there are very few circumstances under which they are not effective, and (c) there are no identified circumstances under which they backfire and lead to undesirable outcomes. PMID:26501228

Prevalence of polycystic ovary syndrome and its associated complications in Iranian women: A meta-analysis

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Anahita Jalilian

2015-10-01

Full Text Available Background: Polycystic ovary syndrome (PCOS is the most common endocrine disorder in women of reproductive age and is the most common cause of infertility due to anovulation. There is no single criterion for the diagnosis of this syndrome. Objective: The purpose of this study was to investigate the prevalence of PCOS and its associated complications in Iranian women using meta-analysis method. Materials and Methods: Prevalence of PCOS was investigated from the SID, Goggle scholar, PubMed, Magiran, Irandoc, and Iranmedex, and weighting of each study was calculated according to sample size and prevalence of the binomial distribution. Data were analyzed using a random-effects model meta-analysis (Random effects model and the software R and Stata Version 11.2. Results: 30 studies conducted between the years 2006 to 2011 were entered into meta-analysis. The total sample size was 19, 226 women aged between 10-45 years. The prevalence of PCOS based on National institute of child health and human disease of the U.S was, 6.8% (95 % CI: 4.11–8.5, based on Rotterdam was 19.5% (95 % CI: 2.24-8.14, and based on ultrasound was 4.41% (95% CI: 5.68-4.14. Also, the prevalence of hirsutism was estimated to be 13%, acne 26%, androgenic alopecia 9%, menstrual disorders 28%, overweight 21%, obesity 19%, and infertility 8%. Conclusion: The prevalence of PCOS in Iran is not high. However, given the risk of complications such as heart disease - cardiovascular and infertility, prevention of PCOS is important; we suggest that health officials must submit plans for the community in this respect.

Flipped classroom improves student learning in health professions education: a meta-analysis.

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Hew, Khe Foon; Lo, Chung Kwan

2018-03-15

The use of flipped classroom approach has become increasingly popular in health professions education. However, no meta-analysis has been published that specifically examines the effect of flipped classroom versus traditional classroom on student learning. This study examined the findings of comparative articles through a meta-analysis in order to summarize the overall effects of teaching with the flipped classroom approach. We focused specifically on a set of flipped classroom studies in which pre-recorded videos were provided before face-to-face class meetings. These comparative articles focused on health care professionals including medical students, residents, doctors, nurses, or learners in other health care professions and disciplines (e.g., dental, pharmacy, environmental or occupational health). Using predefined study eligibility criteria, seven electronic databases were searched in mid-April 2017 for relevant articles. Methodological quality was graded using the Medical Education Research Study Quality Instrument (MERSQI). Effect sizes, heterogeneity estimates, analysis of possible moderators, and publication bias were computed using the COMPREHENSIVE META-ANALYSIS software. A meta-analysis of 28 eligible comparative studies (between-subject design) showed an overall significant effect in favor of flipped classrooms over traditional classrooms for health professions education (standardized mean difference, SMD = 0.33, 95% confidence interval, CI = 0.21-0.46, p flipped classroom approach was more effective when instructors used quizzes at the start of each in-class session. More respondents reported they preferred flipped to traditional classrooms. Current evidence suggests that the flipped classroom approach in health professions education yields a significant improvement in student learning compared with traditional teaching methods.

Plasma L-tryptophan concentration in major depressive disorder: new data and meta-analysis.

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Ogawa, Shintaro; Fujii, Takashi; Koga, Norie; Hori, Hiroaki; Teraishi, Toshiya; Hattori, Kotaro; Noda, Takamasa; Higuchi, Teruhiko; Motohashi, Nobutaka; Kunugi, Hiroshi

2014-09-01

Tryptophan, an essential amino acid, is the precursor to serotonin and is metabolized mainly by the kynurenine pathway. Both serotonin and kynurenine have been implicated in the pathophysiology of major depressive disorder (MDD). However, plasma tryptophan concentration in patients with MDD has not unequivocally been reported to be decreased, which prompted us to perform a meta-analysis on previous studies and our own data. We searched the PubMed database for case-control studies published until August 31, 2013, using the search terms plasma AND tryptophan AND synonyms for MDD. An additional search was performed for the term amino acid instead of tryptophan. We obtained our own data in 66 patients with MDD (DSM-IV) and 82 controls who were recruited from March 2011 to July 2012. The majority of the patients were medicated (N = 53). Total plasma tryptophan concentrations were measured by the liquid chromatography/mass spectrometry method. We scrutinized 160 studies for eligibility. Original articles that were written in English and documented plasma tryptophan values in patients and controls were selected. We included 24 studies from the literature and our own data in the meta-analysis, which involved a total of 744 patients and 793 controls. Data on unmedicated patients (N = 156) and their comparison subjects (N = 203) were also extracted. To see the possible correlation between tryptophan concentrations and depression severity, meta-regression analysis was performed for 10 studies with the Hamilton Depression Rating Scale 17-item version score. In our case-control study, mean (SD) plasma tryptophan level was significantly decreased in the MDD patients versus the controls (53.9 [10.9] vs 57.2 [11.3] μmol/L; P = .03). The meta-analysis after adjusting for publication bias showed a significant decrease in patients with MDD with a modest effect size (Hedges g, -0.45). However, analysis on unmedicated subjects yielded a large effect (Hedges g, -0.84; P = .00015). We

Clinical Effectiveness of Occupational Therapy in Mental Health: A Meta-Analysis.

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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.

Substantia nigra fractional anisotropy is not a diagnostic biomarker of Parkinson's disease: A diagnostic performance study and meta-analysis

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Hirata, Fabiana C.C.; Vieira, Gilson; Lucato, Leandro T.; Leite, Claudia C.; Pastorello, Bruno F.; Otaduy, Maria C.G.; Chaim, Khallil T.; Campanholo, Kenia R. [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Sato, Joao R. [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Universidade Federal do ABC, Center of Mathematics, Computation and Cognition, Santo Andre (Brazil); Bor-Seng-Shu, Edson; Novaes, Natalia P. [Hospital Israelita Albert Einstein, Sao Paulo (Brazil); University of Sao Paulo, Department of Neurology, Sao Paulo (Brazil); Magalhaes Melo, Luciano; Goncalves, Marcia R.; Reis Barbosa, Egberto [University of Sao Paulo, Department of Neurology, Sao Paulo (Brazil); Pereira do Nascimento, Felipe Barjud; Amaro, Edson [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Hospital Israelita Albert Einstein, Sao Paulo (Brazil); Jacobsen Teixeira, Manoel [University of Sao Paulo, Department of Neurosurgery, Sao Paulo (Brazil); Cardoso, Ellison Fernando [University of Sao Paulo, LIM-44, Department of Radiology, Sao Paulo, SP (Brazil); Hospital Israelita Albert Einstein, Sao Paulo (Brazil); Institute of Mathematics and Statistics University of Sao Paulo (IME-USP), Sao Paulo (Brazil)

2017-06-15

Our goal was to estimate the diagnostic accuracy of substantia nigra fractional anisotropy (SN-FA) for Parkinson's disease (PD) diagnosis in a sample similar to the clinical setting, including patients with essential tremor (ET) and healthy controls (HC). We also performed a systematic review and meta-analysis to estimate mean change in SN-FA induced by PD and its diagnostic accuracy. Our sample consisted of 135 subjects: 72 PD, 21 ET and 42 HC. To address inter-scanner variability, two 3.0-T MRI scans were performed. MRI results of this sample were pooled into a meta-analysis that included 1,432 subjects (806 PD and 626 HC). A bivariate model was used to evaluate diagnostic accuracy measures. In our sample, we did not observe a significant effect of disease on SN-FA and it was uninformative for diagnosis. The results of the meta-analysis estimated a 0.03 decrease in mean SN-FA in PD relative to HC (CI: 0.01-0.05). However, the discriminatory capability of SN-FA to diagnose PD was low: pooled sensitivity and specificity were 72 % (CI: 68-75) and 63 % (CI: 58-70), respectively. There was high heterogeneity between studies (I{sup 2} = 91.9 %). SN-FA cannot be used as an isolated measure to diagnose PD. (orig.)

Meta-analysis on shift work and risks of specific obesity types.

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Sun, M; Feng, W; Wang, F; Li, P; Li, Z; Li, M; Tse, G; Vlaanderen, J; Vermeulen, R; Tse, L A

2018-01-01

This systematic review and meta-analysis evaluated the associations between shift work patterns and risks of specific types of obesity. PubMed was searched until March 2017 for observational studies that examined the relationships between shift work patterns and obesity. Odds ratio for obesity was extracted using a fixed-effects or random-effects model. Subgroup meta-analyses were carried out for study design, specific obesity types and characteristics of shift work pattern. A total of 28 studies were included in this meta-analysis. The overall odds ratio of night shift work was 1.23 (95% confidence interval = 1.17-1.29) for risk of obesity/overweight. Cross-sectional studies showed a higher risk of 1.26 than those with the cohort design (risk ratio = 1.10). Shift workers had a higher frequency of developing abdominal obesity (odds ratio = 1.35) than other obesity types. Permanent night workers demonstrated a 29% higher risk than rotating shift workers (odds ratio 1.43 vs. 1.14). This meta-analysis confirmed the risks of night shift work for the development of overweight and obesity with a potential gradient association suggested, especially for abdominal obesity. Modification of working schedules is recommended, particularly for prolonged permanent night work. More accurate and detailed measurements on shift work patterns should be conducted in future research. © 2017 World Obesity Federation.

Does College Teach Critical Thinking? A Meta-Analysis

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Huber, Christopher R.; Kuncel, Nathan R.

2016-01-01

Educators view critical thinking as an essential skill, yet it remains unclear how effectively it is being taught in college. This meta-analysis synthesizes research on gains in critical thinking skills and attitudinal dispositions over various time frames in college. The results suggest that both critical thinking skills and dispositions improve…

Comprehensive School Reform and Achievement: A Meta-Analysis

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Borman, Geoffrey D.; Hewes, Gina M.; Overman, Laura T.; Brown, Shelly

2003-01-01

This meta-analysis reviews research on the achievement effects of comprehensive school reform (CSR) and summarizes the specific effects of 29 widely implemented models. There are limitations on the overall quantity and quality of the research base, but the overall effects of CSR appear promising. The combined quantity, quality, and statistical…

Following celebrities’ medical advice: meta-narrative analysis

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Hoffman, Steven J; Tan, Charlie

2013-01-01

Objective: To synthesise what is known about how celebrities influence people’s decisions on health. Design: Meta-narrative analysis of economics, marketing, psychology, and sociology literatures. Data sources Systematic searches of electronic databases: BusinessSource Complete (1886-), Communication & Mass Media Complete (1915-), Humanities Abstracts (1984-), ProQuest Political Science (1985-), PsycINFO (1806-), PubMed (1966-), and Sociology Abstracts (1952-). Inclusion criteria Studies disc...

Testicular cancer in twins: a meta-analysis.

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Neale, R E; Carrière, P; Murphy, M F G; Baade, P D

2008-01-15

In a meta-analysis of testicular cancer in twins, twins had a 30% increased risk (estimate 1.31, 95% CI 1.1-1.6), providing indirect support for the hypothesis that in utero hormone variations influence risk of testicular cancer. The summary-estimate for dizygotic twins was 1.3 (1.0-1.7) and for monozygotic or same sex twins 1.4 (1.2-1.8).

Ionizing radiation, antioxidant response and oxidative damage: A meta-analysis

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Einor, D., E-mail: daniel@einor.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Bonisoli-Alquati, A., E-mail: andreabonisoli@gmail.com [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, LA 70803 (United States); Costantini, D., E-mail: davidcostantini@libero.it [Department of Biology, University of Antwerp, Wilrijk, B-2610, Antwerp (Belgium); Mousseau, T.A., E-mail: mousseau@sc.edu [Department of Biological Sciences, University of South Carolina, Columbia, SC 29208 (United States); Faculty of Bioscience and Biotechnology, Chubu University, Kasugai (Japan); Møller, A.P., E-mail: anders.moller@u-psud.fr [Laboratoire d' Ecologie, Systématique et Evolution, CNRS UMR 8079, Université Paris-Sud, Bâtiment 362, F-91405 Orsay Cedex (France)

2016-04-01

One mechanism proposed as a link between exposure to ionizing radiation and detrimental effects on organisms is oxidative damage. To test this hypothesis, we surveyed the scientific literature on the effects of chronic low-dose ionizing radiation (LDIR) on antioxidant responses and oxidative damage. We found 40 publications and 212 effect sizes for antioxidant responses and 288 effect sizes for effects of oxidative damage. We performed a meta-analysis of signed and unsigned effect sizes. We found large unsigned effects for both categories (0.918 for oxidative damage; 0.973 for antioxidant response). Mean signed effect size weighted by sample size was 0.276 for oxidative damage and − 0.350 for antioxidant defenses, with significant heterogeneity among effects for both categories, implying that ionizing radiation caused small to intermediate increases in oxidative damage and small to intermediate decreases in antioxidant defenses. Our estimates are robust, as shown by very high fail-safe numbers. Species, biological matrix (tissue, blood, sperm) and age predicted the magnitude of effects for oxidative damage as well as antioxidant response. Meta-regression models showed that effect sizes for oxidative damage varied among species and age classes, while effect sizes for antioxidant responses varied among species and biological matrices. Our results are consistent with the description of mechanisms underlying pathological effects of chronic exposure to LDIR. Our results also highlight the importance of resistance to oxidative stress as one possible mechanism associated with variation in species responses to LDIR-contaminated areas. - Highlights: • There is interest in variation in metabolic effects of chronic low-dose ionizing radiation • A random effect meta-analysis of effect sizes of radioactive contamination was performed • We found significant effects of radiation on oxidative damage and antioxidant response • We found significant heterogeneity among

Questionable assumptions hampered interpretation of a network meta-analysis of primary care depression treatments.

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Linde, Klaus; Rücker, Gerta; Schneider, Antonius; Kriston, Levente

2016-03-01

We aimed to evaluate the underlying assumptions of a network meta-analysis investigating which depression treatment works best in primary care and to highlight challenges and pitfalls of interpretation under consideration of these assumptions. We reviewed 100 randomized trials investigating pharmacologic and psychological treatments for primary care patients with depression. Network meta-analysis was carried out within a frequentist framework using response to treatment as outcome measure. Transitivity was assessed by epidemiologic judgment based on theoretical and empirical investigation of the distribution of trial characteristics across comparisons. Homogeneity and consistency were investigated by decomposing the Q statistic. There were important clinical and statistically significant differences between "pure" drug trials comparing pharmacologic substances with each other or placebo (63 trials) and trials including a psychological treatment arm (37 trials). Overall network meta-analysis produced results well comparable with separate meta-analyses of drug trials and psychological trials. Although the homogeneity and consistency assumptions were mostly met, we considered the transitivity assumption unjustifiable. An exchange of experience between reviewers and, if possible, some guidance on how reviewers addressing important clinical questions can proceed in situations where important assumptions for valid network meta-analysis are not met would be desirable. Copyright © 2016 Elsevier Inc. All rights reserved.

Acupuncture for Alcohol Use Disorder: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Na Young Shin

2017-01-01

Full Text Available Empirical research has produced mixed results regarding the effects of acupuncture on the treatment of alcohol use disorder in humans. Few studies have provided a comprehensive review or a systematic overview of the magnitude of the treatment effect of acupuncture on alcoholism. This study investigated the effects of acupuncture on alcohol-related symptoms and behaviors in patients with this disorder. The PubMed database was searched until 23 August 2016, and reference lists from review studies were also reviewed. Seventeen studies were identified for a full-text inspection, and seven (243 patients of these met our inclusion criteria. The outcomes assessed at the last posttreatment point and any available follow-up data were extracted from each of the studies. Our meta-analysis demonstrated that an acupuncture intervention had a stronger effect on reducing alcohol-related symptoms and behaviors than did the control intervention (g=0.67. A beneficial but weak effect of acupuncture treatment was also found in the follow-up data (g=0.29. Although our analysis showed a significant difference between acupuncture and the control intervention in patients with alcohol use disorder, this meta-analysis is limited by the small number of studies included. Thus, a larger cohort study is required to provide a firm conclusion.