Meta-analysis a structural equation modeling approach

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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

Meta-path based heterogeneous combat network link prediction

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Li, Jichao; Ge, Bingfeng; Yang, Kewei; Chen, Yingwu; Tan, Yuejin

2017-09-01

The combat system-of-systems in high-tech informative warfare, composed of many interconnected combat systems of different types, can be regarded as a type of complex heterogeneous network. Link prediction for heterogeneous combat networks (HCNs) is of significant military value, as it facilitates reconfiguring combat networks to represent the complex real-world network topology as appropriate with observed information. This paper proposes a novel integrated methodology framework called HCNMP (HCN link prediction based on meta-path) to predict multiple types of links simultaneously for an HCN. More specifically, the concept of HCN meta-paths is introduced, through which the HCNMP can accumulate information by extracting different features of HCN links for all the six defined types. Next, an HCN link prediction model, based on meta-path features, is built to predict all types of links of the HCN simultaneously. Then, the solution algorithm for the HCN link prediction model is proposed, in which the prediction results are obtained by iteratively updating with the newly predicted results until the results in the HCN converge or reach a certain maximum iteration number. Finally, numerical experiments on the dataset of a real HCN are conducted to demonstrate the feasibility and effectiveness of the proposed HCNMP, in comparison with 30 baseline methods. The results show that the performance of the HCNMP is superior to those of the baseline methods.

Statistical Power in Meta-Analysis

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Liu, Jin

2015-01-01

Statistical power is important in a meta-analysis study, although few studies have examined the performance of simulated power in meta-analysis. The purpose of this study is to inform researchers about statistical power estimation on two sample mean difference test under different situations: (1) the discrepancy between the analytical power and…

Trial Sequential Analysis in systematic reviews with meta-analysis

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Jørn Wetterslev

2017-03-01

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

Meta-Analysis of Coefficient Alpha

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Rodriguez, Michael C.; Maeda, Yukiko

2006-01-01

The meta-analysis of coefficient alpha across many studies is becoming more common in psychology by a methodology labeled reliability generalization. Existing reliability generalization studies have not used the sampling distribution of coefficient alpha for precision weighting and other common meta-analytic procedures. A framework is provided for…

An Introduction to Path Analysis

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Wolfe, Lee M.

1977-01-01

The analytical procedure of path analysis is described in terms of its use in nonexperimental settings in the social sciences. The description assumes a moderate statistical background on the part of the reader. (JKS)

Random-Effects Models for Meta-Analytic Structural Equation Modeling: Review, Issues, and Illustrations

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Cheung, Mike W.-L.; Cheung, Shu Fai

2016-01-01

Meta-analytic structural equation modeling (MASEM) combines the techniques of meta-analysis and structural equation modeling for the purpose of synthesizing correlation or covariance matrices and fitting structural equation models on the pooled correlation or covariance matrix. Both fixed-effects and random-effects models can be defined in MASEM.…

Transformational Leadership and Organizational Citizenship Behavior: A Meta-Analytic Test of Underlying Mechanisms.

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Nohe, Christoph; Hertel, Guido

2017-01-01

Based on social exchange theory, we examined and contrasted attitudinal mediators (affective organizational commitment, job satisfaction) and relational mediators (trust in leader, leader-member exchange; LMX) of the positive relationship between transformational leadership and organizational citizenship behavior (OCB). Hypotheses were tested using meta-analytic path models with correlations from published meta-analyses (761 samples with 227,419 individuals overall). When testing single-mediator models, results supported our expectations that each of the mediators explained the relationship between transformational leadership and OCB. When testing a multi-mediator model, LMX was the strongest mediator. When testing a model with a latent attitudinal mechanism and a latent relational mechanism, the relational mechanism was the stronger mediator of the relationship between transformational leadership and OCB. Our findings help to better understand the underlying mechanisms of the relationship between transformational leadership and OCB.

A SIMPLE ANALYTICAL METHOD TO DETERMINE SOLAR ENERGETIC PARTICLES' MEAN FREE PATH

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He, H.-Q.; Qin, G.

2011-01-01

To obtain the mean free path of solar energetic particles (SEPs) for a solar event, one usually has to fit time profiles of both flux and anisotropy from spacecraft observations to numerical simulations of SEPs' transport processes. This method can be called a simulation method. But a reasonably good fitting needs a lot of simulations, which demand a large amount of calculation resources. Sometimes, it is necessary to find an easy way to obtain the mean free path of SEPs quickly, for example, in space weather practice. Recently, Shalchi et al. provided an approximate analytical formula of SEPs' anisotropy time profile as a function of particles' mean free path for impulsive events. In this paper, we determine SEPs' mean free path by fitting the anisotropy time profiles from Shalchi et al.'s analytical formula to spacecraft observations. This new method can be called an analytical method. In addition, we obtain SEPs' mean free path with the traditional simulation methods. Finally, we compare the mean free path obtained with the simulation method to that of the analytical method to show that the analytical method, with some minor modifications, can give us a good, quick approximation of SEPs' mean free path for impulsive events.

Negative psychological responses of injury and rehabilitation adherence effects on return to play in competitive athletes: a systematic review and meta-analysis

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Ivarsson A

2017-03-01

Full Text Available Andreas Ivarsson,1 Ulrika Tranaeus,2,3 Urban Johnson,1 Andreas Stenling 4 1Center of Research on Welfare, Health and Sport, School of Health and Welfare, Halmstad University, Halmstad, 2Performance and Training Unit, The Swedish School of Sport and Health Sciences (GIH, 3Musculoskeletal & Sports Injury Epidemiology Center, IMM, Karolinska Institutet, Stockholm, 4Department of Psychology, Umeå University, Umeå, Sweden Abstract: Previous research offers evidence that psychological factors influence an injured athlete during the rehabilitation process. Our first objective was to conduct a systematic review and meta-analysis of the results from all published studies that examined the relationships among negative affective responses after sport injuries, rehabilitation adherence, and return to play (RTP. The second objective was to use a meta-analytic path analysis to investigate whether an indirect effect existed between negative affective responses and RTP through rehabilitation adherence. This literature review resulted in seven studies providing 14 effect sizes. The results from the meta-analysis showed that negative affective responses had a negative effect on successful RTP, whereas rehabilitation adherence had a positive effect on RTP. The results from the meta-analytic path analysis showed a weak and nonsignificant indirect effect of negative affective responses on RTP via rehabilitation adherence. These results underline the importance of providing supportive environments for injured athletes to increase the chances of successful RTP via a decrease in negative affective responses and increase in rehabilitation adherence. Keywords: affective responses, rehabilitation behaviors, return to play, sport injuries

The Meta-Analytic Big Bang

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Shadish, William R.; Lecy, Jesse D.

2015-01-01

This article looks at the impact of meta-analysis and then explores why meta-analysis was developed at the time and by the scholars it did in the social sciences in the 1970s. For the first problem, impact, it examines the impact of meta-analysis using citation network analysis. The impact is seen in the sciences, arts and humanities, and on such…

Thresholds for statistical and clinical significance in systematic reviews with meta-analytic methods

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Jakobsen, Janus Christian; Wetterslev, Jorn; Winkel, Per

2014-01-01

BACKGROUND: Thresholds for statistical significance when assessing meta-analysis results are being insufficiently demonstrated by traditional 95% confidence intervals and P-values. Assessment of intervention effects in systematic reviews with meta-analysis deserves greater rigour. METHODS......: Methodologies for assessing statistical and clinical significance of intervention effects in systematic reviews were considered. Balancing simplicity and comprehensiveness, an operational procedure was developed, based mainly on The Cochrane Collaboration methodology and the Grading of Recommendations...... Assessment, Development, and Evaluation (GRADE) guidelines. RESULTS: We propose an eight-step procedure for better validation of meta-analytic results in systematic reviews (1) Obtain the 95% confidence intervals and the P-values from both fixed-effect and random-effects meta-analyses and report the most...

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.

The meta-analytic big bang.

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Shadish, William R; Lecy, Jesse D

2015-09-01

This article looks at the impact of meta-analysis and then explores why meta-analysis was developed at the time and by the scholars it did in the social sciences in the 1970s. For the first problem, impact, it examines the impact of meta-analysis using citation network analysis. The impact is seen in the sciences, arts and humanities, and on such contemporaneous developments as multilevel modeling, medical statistics, qualitative methods, program evaluation, and single-case design. Using a constrained snowball sample of citations, we highlight key articles that are either most highly cited or most central to the systematic review network. Then, the article examines why meta-analysis came to be in the 1970s in the social sciences through the work of Gene Glass, Robert Rosenthal, and Frank Schmidt, each of whom developed similar theories of meta-analysis at about the same time. The article ends by explaining how Simonton's chance configuration theory and Campbell's evolutionary epistemology can illuminate why meta-analysis occurred with these scholars when it did and not in medical sciences. Copyright © 2015 John Wiley & Sons, Ltd.

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

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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…

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

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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.

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

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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.

Dissociable meta-analytic brain networks contribute to coordinated emotional processing.

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Riedel, Michael C; Yanes, Julio A; Ray, Kimberly L; Eickhoff, Simon B; Fox, Peter T; Sutherland, Matthew T; Laird, Angela R

2018-06-01

Meta-analytic techniques for mining the neuroimaging literature continue to exert an impact on our conceptualization of functional brain networks contributing to human emotion and cognition. Traditional theories regarding the neurobiological substrates contributing to affective processing are shifting from regional- towards more network-based heuristic frameworks. To elucidate differential brain network involvement linked to distinct aspects of emotion processing, we applied an emergent meta-analytic clustering approach to the extensive body of affective neuroimaging results archived in the BrainMap database. Specifically, we performed hierarchical clustering on the modeled activation maps from 1,747 experiments in the affective processing domain, resulting in five meta-analytic groupings of experiments demonstrating whole-brain recruitment. Behavioral inference analyses conducted for each of these groupings suggested dissociable networks supporting: (1) visual perception within primary and associative visual cortices, (2) auditory perception within primary auditory cortices, (3) attention to emotionally salient information within insular, anterior cingulate, and subcortical regions, (4) appraisal and prediction of emotional events within medial prefrontal and posterior cingulate cortices, and (5) induction of emotional responses within amygdala and fusiform gyri. These meta-analytic outcomes are consistent with a contemporary psychological model of affective processing in which emotionally salient information from perceived stimuli are integrated with previous experiences to engender a subjective affective response. This study highlights the utility of using emergent meta-analytic methods to inform and extend psychological theories and suggests that emotions are manifest as the eventual consequence of interactions between large-scale brain networks. © 2018 Wiley Periodicals, Inc.

Meta-Analysis for Sociology – A Measure-Driven Approach

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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

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

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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.

Video game training does not enhance cognitive ability: A comprehensive meta-analytic investigation.

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Sala, Giovanni; Tatlidil, K Semir; Gobet, Fernand

2018-02-01

As a result of considerable potential scientific and societal implications, the possibility of enhancing cognitive ability by training has been one of the most influential topics of cognitive psychology in the last two decades. However, substantial research into the psychology of expertise and a recent series of meta-analytic reviews have suggested that various types of cognitive training (e.g., working memory training) benefit performance only in the trained tasks. The lack of skill generalization from one domain to different ones-that is, far transfer-has been documented in various fields of research such as working memory training, music, brain training, and chess. Video game training is another activity that has been claimed by many researchers to foster a broad range of cognitive abilities such as visual processing, attention, spatial ability, and cognitive control. We tested these claims with three random-effects meta-analytic models. The first meta-analysis (k = 310) examined the correlation between video game skill and cognitive ability. The second meta-analysis (k = 315) dealt with the differences between video game players and nonplayers in cognitive ability. The third meta-analysis (k = 359) investigated the effects of video game training on participants' cognitive ability. Small or null overall effect sizes were found in all three models. These outcomes show that overall cognitive ability and video game skill are only weakly related. Importantly, we found no evidence of a causal relationship between playing video games and enhanced cognitive ability. Video game training thus represents no exception to the general difficulty of obtaining far transfer. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

MetaMetaDB: a database and analytic system for investigating microbial habitability.

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Ching-chia Yang

Full Text Available MetaMetaDB (http://mmdb.aori.u-tokyo.ac.jp/ is a database and analytic system for investigating microbial habitability, i.e., how a prokaryotic group can inhabit different environments. The interaction between prokaryotes and the environment is a key issue in microbiology because distinct prokaryotic communities maintain distinct ecosystems. Because 16S ribosomal RNA (rRNA sequences play pivotal roles in identifying prokaryotic species, a system that comprehensively links diverse environments to 16S rRNA sequences of the inhabitant prokaryotes is necessary for the systematic understanding of the microbial habitability. However, existing databases are biased to culturable prokaryotes and exhibit limitations in the comprehensiveness of the data because most prokaryotes are unculturable. Recently, metagenomic and 16S rRNA amplicon sequencing approaches have generated abundant 16S rRNA sequence data that encompass unculturable prokaryotes across diverse environments; however, these data are usually buried in large databases and are difficult to access. In this study, we developed MetaMetaDB (Meta-Metagenomic DataBase, which comprehensively and compactly covers 16S rRNA sequences retrieved from public datasets. Using MetaMetaDB, users can quickly generate hypotheses regarding the types of environments a prokaryotic group may be adapted to. We anticipate that MetaMetaDB will improve our understanding of the diversity and evolution of prokaryotes.

MetaMetaDB: a database and analytic system for investigating microbial habitability.

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Yang, Ching-chia; Iwasaki, Wataru

2014-01-01

MetaMetaDB (http://mmdb.aori.u-tokyo.ac.jp/) is a database and analytic system for investigating microbial habitability, i.e., how a prokaryotic group can inhabit different environments. The interaction between prokaryotes and the environment is a key issue in microbiology because distinct prokaryotic communities maintain distinct ecosystems. Because 16S ribosomal RNA (rRNA) sequences play pivotal roles in identifying prokaryotic species, a system that comprehensively links diverse environments to 16S rRNA sequences of the inhabitant prokaryotes is necessary for the systematic understanding of the microbial habitability. However, existing databases are biased to culturable prokaryotes and exhibit limitations in the comprehensiveness of the data because most prokaryotes are unculturable. Recently, metagenomic and 16S rRNA amplicon sequencing approaches have generated abundant 16S rRNA sequence data that encompass unculturable prokaryotes across diverse environments; however, these data are usually buried in large databases and are difficult to access. In this study, we developed MetaMetaDB (Meta-Metagenomic DataBase), which comprehensively and compactly covers 16S rRNA sequences retrieved from public datasets. Using MetaMetaDB, users can quickly generate hypotheses regarding the types of environments a prokaryotic group may be adapted to. We anticipate that MetaMetaDB will improve our understanding of the diversity and evolution of prokaryotes.

A Meta-Path-Based Prediction Method for Human miRNA-Target Association

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Jiawei Luo

2016-01-01

Full Text Available MicroRNAs (miRNAs are short noncoding RNAs that play important roles in regulating gene expressing, and the perturbed miRNAs are often associated with development and tumorigenesis as they have effects on their target mRNA. Predicting potential miRNA-target associations from multiple types of genomic data is a considerable problem in the bioinformatics research. However, most of the existing methods did not fully use the experimentally validated miRNA-mRNA interactions. Here, we developed RMLM and RMLMSe to predict the relationship between miRNAs and their targets. RMLM and RMLMSe are global approaches as they can reconstruct the missing associations for all the miRNA-target simultaneously and RMLMSe demonstrates that the integration of sequence information can improve the performance of RMLM. In RMLM, we use RM measure to evaluate different relatedness between miRNA and its target based on different meta-paths; logistic regression and MLE method are employed to estimate the weight of different meta-paths. In RMLMSe, sequence information is utilized to improve the performance of RMLM. Here, we carry on fivefold cross validation and pathway enrichment analysis to prove the performance of our methods. The fivefold experiments show that our methods have higher AUC scores compared with other methods and the integration of sequence information can improve the performance of miRNA-target association prediction.

Updated Meta-Analysis of Learner Control within Educational Technology

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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…

The path dependency theory: analytical framework to study institutional integration. The case of France.

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Trouvé, Hélène; Couturier, Yves; Etheridge, Francis; Saint-Jean, Olivier; Somme, Dominique

2010-06-30

The literature on integration indicates the need for an enhanced theorization of institutional integration. This article proposes path dependence as an analytical framework to study the systems in which integration takes place. PRISMA proposes a model for integrating health and social care services for older adults. This model was initially tested in Quebec. The PRISMA France study gave us an opportunity to analyze institutional integration in France. A qualitative approach was used. Analyses were based on semi-structured interviews with actors of all levels of decision-making, observations of advisory board meetings, and administrative documents. Our analyses revealed the complexity and fragmentation of institutional integration. The path dependency theory, which analyzes the change capacity of institutions by taking into account their historic structures, allows analysis of this situation. The path dependency to the Bismarckian system and the incomplete reforms of gerontological policies generate the coexistence and juxtaposition of institutional systems. In such a context, no institution has sufficient ability to determine gerontology policy and build institutional integration by itself. Using path dependence as an analytical framework helps to understand the reasons why institutional integration is critical to organizational and clinical integration, and the complex construction of institutional integration in France.

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

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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.

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

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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.

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.

Teaching meta-analysis using MetaLight

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Thomas James

2012-10-01

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

An Optimization-Driven Analysis Pipeline to Uncover Biomarkers and Signaling Paths: Cervix Cancer

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Enery Lorenzo

2015-05-01

Full Text Available Establishing how a series of potentially important genes might relate to each other is relevant to understand the origin and evolution of illnesses, such as cancer. High‑throughput biological experiments have played a critical role in providing information in this regard. A special challenge, however, is that of trying to conciliate information from separate microarray experiments to build a potential genetic signaling path. This work proposes a two-step analysis pipeline, based on optimization, to approach meta-analysis aiming to build a proxy for a genetic signaling path.

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 the Predictors of Cyberbullying Perpetration and Victimization

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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…

Meta-analytic framework for sparse K-means to identify disease subtypes in multiple transcriptomic studies.

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Huo, Zhiguang; Ding, Ying; Liu, Silvia; Oesterreich, Steffi; Tseng, George

Disease phenotyping by omics data has become a popular approach that potentially can lead to better personalized treatment. Identifying disease subtypes via unsupervised machine learning is the first step towards this goal. In this paper, we extend a sparse K -means method towards a meta-analytic framework to identify novel disease subtypes when expression profiles of multiple cohorts are available. The lasso regularization and meta-analysis identify a unique set of gene features for subtype characterization. An additional pattern matching reward function guarantees consistent subtype signatures across studies. The method was evaluated by simulations and leukemia and breast cancer data sets. The identified disease subtypes from meta-analysis were characterized with improved accuracy and stability compared to single study analysis. The breast cancer model was applied to an independent METABRIC dataset and generated improved survival difference between subtypes. These results provide a basis for diagnosis and development of targeted treatments for disease subgroups.

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

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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…

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.

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.

A novel bi-level meta-analysis approach: applied to biological pathway analysis.

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Nguyen, Tin; Tagett, Rebecca; Donato, Michele; Mitrea, Cristina; Draghici, Sorin

2016-02-01

The accumulation of high-throughput data in public repositories creates a pressing need for integrative analysis of multiple datasets from independent experiments. However, study heterogeneity, study bias, outliers and the lack of power of available methods present real challenge in integrating genomic data. One practical drawback of many P-value-based meta-analysis methods, including Fisher's, Stouffer's, minP and maxP, is that they are sensitive to outliers. Another drawback is that, because they perform just one statistical test for each individual experiment, they may not fully exploit the potentially large number of samples within each study. We propose a novel bi-level meta-analysis approach that employs the additive method and the Central Limit Theorem within each individual experiment and also across multiple experiments. We prove that the bi-level framework is robust against bias, less sensitive to outliers than other methods, and more sensitive to small changes in signal. For comparative analysis, we demonstrate that the intra-experiment analysis has more power than the equivalent statistical test performed on a single large experiment. For pathway analysis, we compare the proposed framework versus classical meta-analysis approaches (Fisher's, Stouffer's and the additive method) as well as against a dedicated pathway meta-analysis package (MetaPath), using 1252 samples from 21 datasets related to three human diseases, acute myeloid leukemia (9 datasets), type II diabetes (5 datasets) and Alzheimer's disease (7 datasets). Our framework outperforms its competitors to correctly identify pathways relevant to the phenotypes. The framework is sufficiently general to be applied to any type of statistical meta-analysis. The R scripts are available on demand from the authors. sorin@wayne.edu Supplementary data are available at Bioinformatics online. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e

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

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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.

Executive Function and Reading Comprehension: A Meta-Analytic Review

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Follmer, D. Jake

2018-01-01

This article presents a meta-analytic review of the relation between executive function and reading comprehension. Results (N = 6,673) supported a moderate positive association between executive function and reading comprehension (r = 0.36). Moderator analyses suggested that correlations between executive function and reading comprehension did not…

Different presence of Chlamydia pneumoniae, herpes simplex virus type 1, human herpes virus 6, and Toxoplasma gondii in schizophrenia: meta-analysis and analytical study

Directory of Open Access Journals (Sweden)

Gutiérrez-Fernández J

2015-03-01

Full Text Available José Gutiérrez-Fernández,1 Juan de Dios Luna del Castillo,2 Sara Mañanes-González,1 José Antonio Carrillo-Ávila,1 Blanca Gutiérrez,3 Jorge A Cervilla,3 Antonio Sorlózano-Puerto1 1Department of Microbiology, 2Department of Statistics and Operation Research, 3Department of Psychiatry, Institute of Neurosciences and CIBERSAM, School of Medicine and Biohealth Research Institute (Instituto de Investigación Biosanitaria IBS-Granada, University of Granada, Granada, Spain Abstract: In the present study we have performed both a meta-analysis and an analytical study exploring the presence of Chlamydia pneumoniae, herpes simplex virus type 1, human herpes virus 6, and Toxoplasma gondii antibodies in a sample of 143 schizophrenic patients and 143 control subjects. The meta-analysis was performed on papers published up to April 2014. The presence of serum immunoglobulin G and immunoglobulin A was performed by enzyme-linked immunosorbent assay test. The detection of microbial DNA in total peripheral blood was performed by nested polymerase chain reaction. The meta-analysis showed that: 1 C. pneumoniae DNA in blood and brain are more common in schizophrenic patients; 2 there is association with parasitism by T. gondii, despite the existence of publication bias; and 3 herpes viruses were not more common in schizophrenic patients. In our sample only anti-Toxoplasma immunoglobulin G was more prevalent and may be a risk factor related to schizophrenia, with potential value for prevention. Keywords: meta-analysis, analytical study, Chlamydia pneumoniae, herpes simplex virus type 1, human herpes virus 6, Toxoplasma gondii, schizophrenia

A Meta-analytic Review of Religious or Spiritual Involvement and Social Health among Cancer Patients

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

2015-01-01

Background Religion and spirituality (R/S) play an important role in the daily lives of many cancer patients. There has been great interest in determining whether R/S factors are related to clinically-relevant health outcomes. This meta-analytic review examined associations between dimensions of R/S and social health (e.g., social roles and relationships). Methods A systematic search of PubMed, PsycInfo, Cochrane Library, and CINAHL databases was conducted, and data were extracted by four pairs of investigators. Bivariate associations between specific R/S dimensions and social health outcomes were examined in a meta-analysis using a generalized estimating equation (GEE) approach. Results A total of 78 independent samples encompassing 14,277 patients were included in the meta-analysis. Social health was significantly associated with overall R/S (Fisher z effect size = .20, Pcancer. Further research is needed to examine the temporal nature of these associations and the mechanisms that underlie them. PMID:26258730

Community-Based Mental Health and Behavioral Programs for Low-Income Urban Youth: A Meta-Analytic Review

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Farahmand, Farahnaz K.; Duffy, Sophia N.; Tailor, Megha A.; Dubois, David L.; Lyon, Aaron L.; Grant, Kathryn E.; Zarlinski, Jennifer C.; Masini, Olivia; Zander, Keith J.; Nathanson, Alison M.

2012-01-01

A meta-analytic review of 33 studies and 41 independent samples was conducted of the effectiveness of community-based mental health and behavioral programs for low-income urban youth. Findings indicated positive effects, with an overall mean effect of 0.25 at post-test. While this is comparable to previous meta-analytic intervention research with…

Meta-analysis with R

CERN Document Server

Schwarzer, Guido; Rücker, Gerta

2015-01-01

This book provides a comprehensive introduction to performing meta-analysis using the statistical software R. It is intended for quantitative researchers and students in the medical and social sciences who wish to learn how to perform meta-analysis with R. As such, the book introduces the key concepts and models used in meta-analysis. It also includes chapters on the following advanced topics: publication bias and small study effects; missing data; multivariate meta-analysis, network meta-analysis; and meta-analysis of diagnostic studies.  .

A Review of Level 2 Parent-Report Instruments Used to Screen Children Aged 1.5-5 for Autism: A Meta-Analytic Update

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Hampton, Justin; Strand, Paul S.

2015-01-01

The present study utilized meta-analytic procedures to estimate the diagnostic validity of instruments used to screen young children, ages 1.5-5 years, for autism. Five scales met inclusion criteria, and data from 18 studies contributed the meta-analysis. Results revealed that 4 of 5 scales met criteria for "good" validity, including two…

Meta-Analysis inside and outside Particle Physics: Convergence Using the Path of Least Resistance?

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Jackson, Dan; Baker, Rose

2013-01-01

In this note, we explain how the method proposed by Hartung and Knapp provides a compromise between conventional meta-analysis methodology and "unconstrained averaging", as used by the Particle Data Group.

Perceived Discrimination and Health: A Meta-Analytic Review

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Pascoe, Elizabeth A.; Richman, Laura Smart

2009-01-01

Perceived discrimination has been studied with regard to its impact on several types of health effects. This meta-analysis provides a comprehensive account of the relationships between multiple forms of perceived discrimination and both mental and physical health outcomes. In addition, this meta-analysis examines potential mechanisms by which…

Action Video Game Training for Healthy Adults: A Meta-Analytic Study.

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Wang, Ping; Liu, Han-Hui; Zhu, Xing-Ting; Meng, Tian; Li, Hui-Jie; Zuo, Xi-Nian

2016-01-01

Action video game (AVG) has attracted increasing attention from both the public and from researchers. More and more studies found video game training improved a variety of cognitive functions. However, it remains controversial whether healthy adults can benefit from AVG training, and whether young and older adults benefit similarly from AVG training. In the present study, we aimed to quantitatively assess the AVG training effect on the cognitive ability of adults and to compare the training effects on young and older adults by conducting a meta-analysis on previous findings. We systematically searched video game training studies published between January 1986 and July 2015. Twenty studies were included in the present meta-analysis, for a total of 313 participants included in the training group and 323 participants in the control group. The results demonstrate that healthy adults achieve moderate benefit from AVG training in overall cognitive ability and moderate to small benefit in specific cognitive domains. In contrast, young adults gain more benefits from AVG training than older adults in both overall cognition and specific cognitive domains. Age, education, and some methodological factors, such as the session duration, session number, total training duration, and control group type, modulated the training effects. These meta-analytic findings provide evidence that AVG training may serve as an efficient way to improve the cognitive performance of healthy adults. We also discussed several directions for future AVG training studies.

A Meta-Analysis of Behavioral Parent Training for Children with Attention Deficit Hyperactivity Disorder

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Lee, Pei-chin; Niew, Wern-ing; Yang, Hao-jan; Chen, Vincent Chin-hung; Lin, Keh-chung

2012-01-01

This meta-analysis examined the effect of behavioral parent training on child and parental outcomes for children with attention deficit hyperactivity disorder. Meta-analytic procedures were used to estimate the effect of behavioral parent training on children with attention deficit hyperactivity disorder. Variables moderating the intervention…

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

meta-analytic studies are described (selection, code, data filtration. The most common analysis (graph, adjustments are presented, the choice of the statistical model (a qualitative explanatory factor, a qualitative or quantitative effect, the interference factors and the post-analytic procedures (residual variations, heterogeneity among results. In conclusion, this text shows that meta-analysis is better than traditional methods of literature review for esteeming with more precision the treatments effects adjusting it's for the experimental heterogeneity. However, the meta-analysis requires discipline in the systematization and analysis of the research results.

Violent video game effects on aggression, empathy, and prosocial behavior in Eastern and Western countries: A meta-analytic review

NARCIS (Netherlands)

Anderson, C.A.; Shibuya, A.; Ihori, N.; Swing, E.L.; Bushman, B.J.; Sakamoto, A.; Rothstein, H.R.; Saleem, M.; Barlett, C.P.

2010-01-01

Meta-analytic procedures were used to test the effects of violent video games on aggressive behavior, aggressive cognition, aggressive affect, physiological arousal, empathy/desensitization, and prosocial behavior. Unique features of this meta-analytic review include (a) more restrictive

Meta-analysis of choice set generation effects on route choice model estimates and predictions

DEFF Research Database (Denmark)

Prato, Carlo Giacomo

2012-01-01

are applied for model estimation and results are compared to the ‘true model estimates’. Last, predictions from the simulation of models estimated with objective choice sets are compared to the ‘postulated predicted routes’. A meta-analytical approach allows synthesizing the effect of judgments......Large scale applications of behaviorally realistic transport models pose several challenges to transport modelers on both the demand and the supply sides. On the supply side, path-based solutions to the user assignment equilibrium problem help modelers in enhancing the route choice behavior...... modeling, but require them to generate choice sets by selecting a path generation technique and its parameters according to personal judgments. This paper proposes a methodology and an experimental setting to provide general indications about objective judgments for an effective route choice set generation...

The Significance of Attachment Quality for Obesity : A Meta-Analytic Review

NARCIS (Netherlands)

Diener, Marc J.; Geenen, Rinie; Koelen, Jurrijn A.; Aarts, Floor; Gerdes, Victor E. A.; Brandjes, Dees P. M.; Hinnen, Chris

2016-01-01

Theoretical considerations and empirical results suggest that attachment quality is relevant to obesity. This study used meta-analytic methods to systematically examine the empirical, peer-reviewed evidence regarding the relationship between attachment quality and body mass index (BMI) in separate

Meta-analysis as Statistical and Analytical Method of Journal's Content Scientific Evaluation.

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Masic, Izet; Begic, Edin

2015-02-01

A meta-analysis is a statistical and analytical method which combines and synthesizes different independent studies and integrates their results into one common result. Analysis of the journals "Medical Archives", "Materia Socio Medica" and "Acta Informatica Medica", which are located in the most eminent indexed databases of the biomedical milieu. The study has retrospective and descriptive character, and included the period of the calendar year 2014. Study included six editions of all three journals (total of 18 journals). In this period was published a total of 291 articles (in the "Medical Archives" 110, "Materia Socio Medica" 97, and in "Acta Informatica Medica" 84). The largest number of articles was original articles. Small numbers have been published as professional, review articles and case reports. Clinical events were most common in the first two journals, while in the journal "Acta Informatica Medica" belonged to the field of medical informatics, as part of pre-clinical medical disciplines. Articles are usually required period of fifty to fifty nine days for review. Articles were received from four continents, mostly from Europe. The authors are most often from the territory of Bosnia and Herzegovina, then Iran, Kosovo and Macedonia. The number of articles published each year is increasing, with greater participation of authors from different continents and abroad. Clinical medical disciplines are the most common, with the broader spectrum of topics and with a growing number of original articles. Greater support of the wider scientific community is needed for further development of all three of the aforementioned journals.

Unique effects and moderators of effects of sources on self-efficacy: A model-based meta-analysis.

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Byars-Winston, Angela; Diestelmann, Jacob; Savoy, Julia N; Hoyt, William T

2017-11-01

Self-efficacy beliefs are strong predictors of academic pursuits, performance, and persistence, and in theory are developed and maintained by 4 classes of experiences Bandura (1986) referred to as sources: performance accomplishments (PA), vicarious learning (VL), social persuasion (SP), and affective arousal (AA). The effects of sources on self-efficacy vary by performance domain and individual difference factors. In this meta-analysis (k = 61 studies of academic self-efficacy; N = 8,965), we employed B. J. Becker's (2009) model-based approach to examine cumulative effects of the sources as a set and unique effects of each source, controlling for the others. Following Becker's recommendations, we used available data to create a correlation matrix for the 4 sources and self-efficacy, then used these meta-analytically derived correlations to test our path model. We further examined moderation of these associations by subject area (STEM vs. non-STEM), grade, sex, and ethnicity. PA showed by far the strongest unique association with self-efficacy beliefs. Subject area was a significant moderator, with sources collectively predicting self-efficacy more strongly in non-STEM (k = 14) compared with STEM (k = 47) subjects (R2 = .37 and .22, respectively). Within studies of STEM subjects, grade level was a significant moderator of the coefficients in our path model, as were 2 continuous study characteristics (percent non-White and percent female). Practical implications of the findings and future research directions are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

A meta-analytic investigation of the relation between interpersonal attraction and enacted behavior.

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Montoya, R Matthew; Kershaw, Christine; Prosser, Julie L

2018-05-07

We present a meta-analysis that investigated the relation between self-reported interpersonal attraction and enacted behavior. Our synthesis focused on (a) identifying the behaviors related to attraction; (b) evaluating the efficacy of models of the relation between attraction and behavior; (c) testing the impact of several moderators, including evaluative threat salience, cognitive appraisal salience, and the sex composition of the social interaction; and (d) investigating the degree of agreement between the meta-analytic findings and an ethnographic analysis. Using a multilevel modeling approach, an analysis of 309 effect sizes (N = 5,422) revealed a significant association (z = .20) between self-reported attraction and enacted behavior. Key findings include: (a) that the specific behaviors associated with attraction (e.g., eye contact, smiling, laughter, mimicry) are those behaviors research has linked to the development of trust/rapport; (b) direct behaviors (e.g., physical proximity, talking to), compared with indirect behaviors (e.g., eye contact, smiling, mimicry), were more strongly related to self-reported attraction; and (c) evaluative threat salience (e.g., fear of rejection) reduced the magnitude of the relation between direct behavior and affective attraction. Moreover, an ethnographic analysis revealed consistency between the behaviors identified by the meta-analysis and those behaviors identified by ethnographers as predictive of attraction. We discuss the implications of our findings for models of the relation between attraction and behavior, for the behavioral expressions of emotions, and for how attraction is measured and conceptualized. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Violent Video Game Effects on Aggression, Empathy, and Prosocial Behavior in Eastern and Western Countries: A Meta-Analytic Review

Science.gov (United States)

Anderson, Craig A.; Shibuya, Akiko; Ihori, Nobuko; Swing, Edward L.; Bushman, Brad J.; Sakamoto, Akira; Rothstein, Hannah R.; Saleem, Muniba

2010-01-01

Meta-analytic procedures were used to test the effects of violent video games on aggressive behavior, aggressive cognition, aggressive affect, physiological arousal, empathy/desensitization, and prosocial behavior. Unique features of this meta-analytic review include (a) more restrictive methodological quality inclusion criteria than in past…

Online Programs as Tools to Improve Parenting: A meta-analytic review

NARCIS (Netherlands)

Prof. Dr. Jo J.M.A Hermanns; Prof. Dr. Ruben R.G. Fukkink; dr. Christa C.C. Nieuwboer

2013-01-01

Background. A number of parenting programs, aimed at improving parenting competencies,have recently been adapted or designed with the use of online technologies. Although webbased services have been claimed to hold promise for parent support, a meta-analytic review of online parenting interventions

Online programs as tools to improve parenting: A meta-analytic review

NARCIS (Netherlands)

Nieuwboer, C.C.; Fukkink, R.G.; Hermanns, J.M.A.

2013-01-01

Background: A number of parenting programs, aimed at improving parenting competencies, have recently been adapted or designed with the use of online technologies. Although web-based services have been claimed to hold promise for parent support, a meta-analytic review of online parenting

The structure of common emotion regulation strategies: A meta-analytic examination.

Science.gov (United States)

Naragon-Gainey, Kristin; McMahon, Tierney P; Chacko, Thomas P

2017-04-01

Emotion regulation has been examined extensively with regard to important outcomes, including psychological and physical health. However, the literature includes many different emotion regulation strategies but little examination of how they relate to one another, making it difficult to interpret and synthesize findings. The goal of this meta-analysis was to examine the underlying structure of common emotion regulation strategies (i.e., acceptance, behavioral avoidance, distraction, experiential avoidance, expressive suppression, mindfulness, problem solving, reappraisal, rumination, worry), and to evaluate this structure in light of theoretical models of emotion regulation. We also examined how distress tolerance-an important emotion regulation ability -relates to strategy use. We conducted meta-analyses estimating the correlations between emotion regulation strategies (based on 331 samples and 670 effect sizes), as well as between distress tolerance and strategies. The resulting meta-analytic correlation matrix was submitted to confirmatory and exploratory factor analyses. None of the confirmatory models, based on prior theory, was an acceptable fit to the data. Exploratory factor analysis suggested that 3 underlying factors best characterized these data. Two factors-labeled Disengagement and Aversive Cognitive Perseveration-emerged as strongly correlated but distinct factors, with the latter consisting of putatively maladaptive strategies. The third factor, Adaptive Engagement, was a less unified factor and weakly related to the other 2 factors. Distress tolerance was most closely associated with low levels of repetitive negative thought and experiential avoidance, and high levels of acceptance and mindfulness. We discuss the theoretical implications of these findings and applications to emotion regulation assessment. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

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

MetaPath: An Electronic Knowledge Base for Collating, Exchanging and Analyzing Case Studies of Xenobiotic Metabolism

Science.gov (United States)

A new MetaPath information system was developed through a collaborative effort between the Laboratory of Mathematical Chemistry (Bourgas, Bulgaria), EPA’s Office of Research and Development (NHEERL, MED, Duluth, MN and NERL, ERD, Athens, GA), and EPA’s Office of Chemical Safety a...

PARCELLATION OF THE CINGULATE CORTEX AT REST AND DURING TASKS: A META-ANALYTIC CLUSTERING AND EXPERIMENTAL STUDY

Directory of Open Access Journals (Sweden)

Diana M.E. Torta

2013-06-01

Full Text Available Anatomical, morphological and histological data have consistently shown that the cingulate cortex can be divided into four main regions. However, less is known about parcellations of the cingulate cortex when involved in active tasks. Here, we aimed at comparing how the pattern of clusterization of the cingulate cortex changes across different levels of task complexity. We parcellated the cingulate cortex using the results of a meta-analytic study and of three experimental studies. The experimental studies, which included two active tasks and a resting state protocol, were used to control the results obtained with the meta-analytic parcellation. We explored the meta-analytic parcellation by applying a meta-analytic clustering (MaC to papers retrieved from the BrainMap database. The MaC is a meta-analytic connectivity driven parcellation technique recently developed by our group which allowed us to parcellate the cingulate cortex on the basis of its pattern of co-activations during active tasks. The MaC results indicated that the cingulate cortex can be parcellated into three clusters. These clusters covered different percentages of the cingulate parenchyma and had a different density of foci, with the first cluster being more densely connected. The control experiments showed different clusterization results, suggesting that the co-activations of the cingulate cortex are highly dependent on the task that is tested. Our results highlight the importance of the cingulate cortex as a hub, which modifies its pattern of co-activations depending on the task requests and on the level of task complexity. The neurobiological meaning of these results is discussed.

Prevalence of burnout syndrome in oncology nursing: A meta-analytic study.

Science.gov (United States)

Cañadas-De la Fuente, Guillermo A; Gómez-Urquiza, Jose L; Ortega-Campos, Elena M; Cañadas, Gustavo R; Albendín-García, Luis; De la Fuente-Solana, Emilia I

2018-05-01

To determine the prevalence of high levels of emotional exhaustion and depersonalization and low personal accomplishment in nursing professionals in oncology services. A meta-analytical study was performed. The search was carried out in March 2017 in Pubmed, CINAHL, Scopus, Scielo, Proquest, CUIDEN, and LILACS databases. Studies using Maslach Burnout Inventory for the assessment of burnout were included. The total sample of oncology nurses was n = 9959. The total number of included studies was n = 17, with n = 21 samples for the meta-analysis of emotional exhaustion and n = 18 for depersonalization and low personal accomplishment. The prevalence of emotional exhaustion and of depersonalization was 30% (95% CI = 26%-33%) and 15% (95% CI = 9%-23%), respectively, and that of low personal performance was 35% (95% CI = 27%-43%). The are many oncology nurses with emotional exhaustion and low levels of personal accomplishment. The presence and the risk of burnout among these staff members are considerable. Copyright © 2018 John Wiley & Sons, Ltd.

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

Science.gov (United States)

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

Science.gov (United States)

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

Meta-analytic structural equation modelling

CERN Document Server

Jak, Suzanne

2015-01-01

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

Associations between rejection sensitivity and mental health outcomes : A meta-analytic review

NARCIS (Netherlands)

Gao, S.; Assink, M.; Cipriani, A.; Lin, K.

2017-01-01

Rejection sensitivity is a personality disposition characterized by oversensitivity to social rejection. Using a three-level meta-analytic model, 75 studies were reviewed that examined associations between rejection sensitivity and five mental health outcomes: depression, anxiety, loneliness,

Behavioural effects of advanced cruise control use : a meta-analytic approach.

NARCIS (Netherlands)

Dragutinovic, N. Brookhuis, K.A. Hagenzieker, M.P. & Marchau, V.A.W.J.

2006-01-01

In this study, a meta-analytic approach was used to analyse effects of Advanced Cruise Control (ACC) on driving behaviour reported in seven driving simulator studies. The effects of ACC on three consistent outcome measures, namely, driving speed, headway and driver workload have been analysed. The

Saving lives: A meta-analysis of team training in healthcare.

Science.gov (United States)

Hughes, Ashley M; Gregory, Megan E; Joseph, Dana L; Sonesh, Shirley C; Marlow, Shannon L; Lacerenza, Christina N; Benishek, Lauren E; King, Heidi B; Salas, Eduardo

2016-09-01

As the nature of work becomes more complex, teams have become necessary to ensure effective functioning within organizations. The healthcare industry is no exception. As such, the prevalence of training interventions designed to optimize teamwork in this industry has increased substantially over the last 10 years (Weaver, Dy, & Rosen, 2014). Using Kirkpatrick's (1956, 1996) training evaluation framework, we conducted a meta-analytic examination of healthcare team training to quantify its effectiveness and understand the conditions under which it is most successful. Results demonstrate that healthcare team training improves each of Kirkpatrick's criteria (reactions, learning, transfer, results; d = .37 to .89). Second, findings indicate that healthcare team training is largely robust to trainee composition, training strategy, and characteristics of the work environment, with the only exception being the reduced effectiveness of team training programs that involve feedback. As a tertiary goal, we proposed and found empirical support for a sequential model of healthcare team training where team training affects results via learning, which leads to transfer, which increases results. We find support for this sequential model in the healthcare industry (i.e., the current meta-analysis) and in training across all industries (i.e., using meta-analytic estimates from Arthur, Bennett, Edens, & Bell, 2003), suggesting the sequential benefits of training are not unique to medical teams. Ultimately, this meta-analysis supports the expanded use of team training and points toward recommendations for optimizing its effectiveness within healthcare settings. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Graph Regularized Meta-path Based Transductive Regression in Heterogeneous Information Network.

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Wan, Mengting; Ouyang, Yunbo; Kaplan, Lance; Han, Jiawei

2015-01-01

A number of real-world networks are heterogeneous information networks, which are composed of different types of nodes and links. Numerical prediction in heterogeneous information networks is a challenging but significant area because network based information for unlabeled objects is usually limited to make precise estimations. In this paper, we consider a graph regularized meta-path based transductive regression model ( Grempt ), which combines the principal philosophies of typical graph-based transductive classification methods and transductive regression models designed for homogeneous networks. The computation of our method is time and space efficient and the precision of our model can be verified by numerical experiments.

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

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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.

LitPathExplorer: a confidence-based visual text analytics tool for exploring literature-enriched pathway models.

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Soto, Axel J; Zerva, Chrysoula; Batista-Navarro, Riza; Ananiadou, Sophia

2018-04-15

Pathway models are valuable resources that help us understand the various mechanisms underpinning complex biological processes. Their curation is typically carried out through manual inspection of published scientific literature to find information relevant to a model, which is a laborious and knowledge-intensive task. Furthermore, models curated manually cannot be easily updated and maintained with new evidence extracted from the literature without automated support. We have developed LitPathExplorer, a visual text analytics tool that integrates advanced text mining, semi-supervised learning and interactive visualization, to facilitate the exploration and analysis of pathway models using statements (i.e. events) extracted automatically from the literature and organized according to levels of confidence. LitPathExplorer supports pathway modellers and curators alike by: (i) extracting events from the literature that corroborate existing models with evidence; (ii) discovering new events which can update models; and (iii) providing a confidence value for each event that is automatically computed based on linguistic features and article metadata. Our evaluation of event extraction showed a precision of 89% and a recall of 71%. Evaluation of our confidence measure, when used for ranking sampled events, showed an average precision ranging between 61 and 73%, which can be improved to 95% when the user is involved in the semi-supervised learning process. Qualitative evaluation using pair analytics based on the feedback of three domain experts confirmed the utility of our tool within the context of pathway model exploration. LitPathExplorer is available at http://nactem.ac.uk/LitPathExplorer_BI/. sophia.ananiadou@manchester.ac.uk. Supplementary data are available at Bioinformatics online.

Enhancing Treatment Outcome of Patients at Risk of Treatment Failure: Meta-Analytic and Mega-Analytic Review of a Psychotherapy Quality Assurance System

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Shimokawa, Kenichi; Lambert, Michael J.; Smart, David W.

2010-01-01

Objective: Outcome research has documented worsening among a minority of the patient population (5% to 10%). In this study, we conducted a meta-analytic and mega-analytic review of a psychotherapy quality assurance system intended to enhance outcomes in patients at risk of treatment failure. Method: Original data from six major studies conducted…

Meta-analytically informed network analysis of resting state FMRI reveals hyperconnectivity in an introspective socio-affective network in depression.

Directory of Open Access Journals (Sweden)

Leonhard Schilbach

Full Text Available Alterations of social cognition and dysfunctional interpersonal expectations are thought to play an important role in the etiology of depression and have, thus, become a key target of psychotherapeutic interventions. The underlying neurobiology, however, remains elusive. Based upon the idea of a close link between affective and introspective processes relevant for social interactions and alterations thereof in states of depression, we used a meta-analytically informed network analysis to investigate resting-state functional connectivity in an introspective socio-affective (ISA network in individuals with and without depression. Results of our analysis demonstrate significant differences between the groups with depressed individuals showing hyperconnectivity of the ISA network. These findings demonstrate that neurofunctional alterations exist in individuals with depression in a neural network relevant for introspection and socio-affective processing, which may contribute to the interpersonal difficulties that are linked to depressive symptomatology.

Caffeine ingestion enhances Wingate performance: a meta-analysis.

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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.

Programmed Instruction in Secondary Education: A Meta-Analysis of the Impact of Class Size on Its Effectiveness.

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Boden, Andrea; Archwamety, Teara; McFarland, Max

This review used meta-analytic techniques to integrate findings from 30 independent studies that compared programmed instruction to conventional methods of instruction at the secondary level. The meta-analysis demonstrated that programmed instruction resulted in higher achievement when compared to conventional methods of instruction (average…

A Meta-Analytic Review of School-Based Prevention for Cannabis Use

Science.gov (United States)

Porath-Waller, Amy J.; Beasley, Erin; Beirness, Douglas J.

2010-01-01

This investigation used meta-analytic techniques to evaluate the effectiveness of school-based prevention programming in reducing cannabis use among youth aged 12 to 19. It summarized the results from 15 studies published in peer-reviewed journals since 1999 and identified features that influenced program effectiveness. The results from the set of…

Job burnout and employee engagement : A meta-analytic examination of construct proliferation

NARCIS (Netherlands)

Cole, M.S.; Walter, F.; Bedeian, A.G.; O'Boyle, E.H.

Drawing on 50 unique samples (from 37 studies), the authors used meta-analytical techniques to assess the extent to which job burnout and employee engagement are independent and useful constructs. The authors found that (a) dimension-level correlations between burnout and engagement are high, (b)

Bridging meta-analysis and the comparative method: a test of seed size effect on germination after frugivores' gut passage.

Science.gov (United States)

Verdú, Miguel; Traveset, Anna

2004-02-01

Most studies using meta-analysis try to establish relationships between traits across taxa from interspecific databases and, thus, the phylogenetic relatedness among these taxa should be taken into account to avoid pseudoreplication derived from common ancestry. This paper illustrates, with a representative example of the relationship between seed size and the effect of frugivore's gut on seed germination, that meta-analytic procedures can also be phylogenetically corrected by means of the comparative method. The conclusions obtained in the meta-analytical and phylogenetical approaches are very different. The meta-analysis revealed that the positive effects that gut passage had on seed germination increased with seed size in the case of gut passage through birds whereas decreased in the case of gut passage through non-flying mammals. However, once the phylogenetic relatedness among plant species was taken into account, the effects of gut passage on seed germination did not depend on seed size and were similar between birds and non-flying mammals. Some methodological considerations are given to improve the bridge between the meta-analysis and the comparative method.

Likelihood ratio meta-analysis: New motivation and approach for an old method.

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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.

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

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.

Longitudinal Meta-analysis

NARCIS (Netherlands)

Hox, J.J.; Maas, C.J.M.; Lensvelt-Mulders, G.J.L.M.

2004-01-01

The goal of meta-analysis is to integrate the research results of a number of studies on a specific topic. Characteristic for meta-analysis is that in general only the summary statistics of the studies are used and not the original data. When the published research results to be integrated

Meta-analysis as Statistical and Analytical Method of Journal’s Content Scientific Evaluation

Science.gov (United States)

Masic, Izet; Begic, Edin

2015-01-01

Introduction: A meta-analysis is a statistical and analytical method which combines and synthesizes different independent studies and integrates their results into one common result. Goal: Analysis of the journals “Medical Archives”, “Materia Socio Medica” and “Acta Informatica Medica”, which are located in the most eminent indexed databases of the biomedical milieu. Material and methods: The study has retrospective and descriptive character, and included the period of the calendar year 2014. Study included six editions of all three journals (total of 18 journals). Results: In this period was published a total of 291 articles (in the “Medical Archives” 110, “Materia Socio Medica” 97, and in “Acta Informatica Medica” 84). The largest number of articles was original articles. Small numbers have been published as professional, review articles and case reports. Clinical events were most common in the first two journals, while in the journal “Acta Informatica Medica” belonged to the field of medical informatics, as part of pre-clinical medical disciplines. Articles are usually required period of fifty to fifty nine days for review. Articles were received from four continents, mostly from Europe. The authors are most often from the territory of Bosnia and Herzegovina, then Iran, Kosovo and Macedonia. Conclusion: The number of articles published each year is increasing, with greater participation of authors from different continents and abroad. Clinical medical disciplines are the most common, with the broader spectrum of topics and with a growing number of original articles. Greater support of the wider scientific community is needed for further development of all three of the aforementioned journals. PMID:25870484

Analysis and synthesis of bianisotropic metasurfaces by using analytical approach based on equivalent parameters

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Danaeifar, Mohammad; Granpayeh, Nosrat

2018-03-01

An analytical method is presented to analyze and synthesize bianisotropic metasurfaces. The equivalent parameters of metasurfaces in terms of meta-atom properties and other specifications of metasurfaces are derived. These parameters are related to electric, magnetic, and electromagnetic/magnetoelectric dipole moments of the bianisotropic media, and they can simplify the analysis of complicated and multilayer structures. A metasurface of split ring resonators is studied as an example demonstrating the proposed method. The optical properties of the meta-atom are explored, and the calculated polarizabilities are applied to find the reflection coefficient and the equivalent parameters of the metasurface. Finally, a structure consisting of two metasurfaces of the split ring resonators is provided, and the proposed analytical method is applied to derive the reflection coefficient. The validity of this analytical approach is verified by full-wave simulations which demonstrate good accuracy of the equivalent parameter method. This method can be used in the analysis and synthesis of bianisotropic metasurfaces with different materials and in different frequency ranges by considering electric, magnetic, and electromagnetic/magnetoelectric dipole moments.

The Effect of Gender on Organizational Commitment of Teachers: A Meta Analytic Analysis

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Aydin, Ayhan; Sarier, Yilmaz; Uysal, Sengul

2011-01-01

The purpose of this study is to determine the effect of gender on the organizational commitment of teachers. In this respect, the levels of organizational commitment were also investigated with organizational commitment. Fifteen master and doctorate theses done between 2005-2009 were analyzed using meta analysis. At the end of the research study,…

Communication attitudes in children who stutter: A meta-analytic review.

Science.gov (United States)

Guttormsen, Linn Stokke; Kefalianos, Elaina; Næss, Kari-Anne B

2015-12-01

This article presents a meta-analytic review of differences in communication attitudes between children who stutter (CWS) and children who do not stutter (CWNS). To be included in this review, the studies had to include a group of CWS and CWNS between the ages of 3-18 years and a measurement of communication attitudes. The journal articles were identified by using the key words stutter*, speech disfluenc*, fluency disorder*, and stammer* cross-referenced to awareness*, reaction*, attitude*, KiddyCAT, CAT, A-19 Scale, PASS and OASES. A total of 18 studies met the inclusion criteria for this meta-analysis. The results showed that CWS exhibit more negative communication attitudes than CWNS from the preschool years. The differences between the groups increased with age, but were not influenced by gender. The results indicate that negative communication attitudes can be an effect of stuttering. Key issues requiring further investigation are whether communication attitudes differ as a function of age at stuttering onset and whether communication attitudes influence the development of stuttering. After reading this article, the reader will be able to: (a) summarise empirical findings with regard to the relationship between communication attitudes and childhood stuttering; (b) describe the different instruments used to measure communication attitudes; (c) discuss the relationship between communication attitudes, age and gender. Copyright © 2015 Elsevier Inc. All rights reserved.

Aspartame and Risk of Cancer: A Meta-analytic Review.

Science.gov (United States)

Mallikarjun, Sreekanth; Sieburth, Rebecca McNeill

2015-01-01

Aspartame (APM) is the most commonly used artificial sweetener and flavor enhancer in the world. There is a rise in concern that APM is carcinogenic due to a variation in the findings of the previous APM carcinogenic bioassays. This article conducts a meta-analytic review of all previous APM carcinogenic bioassays on rodents that were conducted before 31 December 2012. The search yielded 10 original APM carcinogenic bioassays on rodents. The aggregate effect sizes suggest that APM consumption has no significant carcinogenic effect in rodents.

MetaGenyo: a web tool for meta-analysis of genetic association studies.

Science.gov (United States)

Martorell-Marugan, Jordi; Toro-Dominguez, Daniel; Alarcon-Riquelme, Marta E; Carmona-Saez, Pedro

2017-12-16

Genetic association studies (GAS) aims to evaluate the association between genetic variants and phenotypes. In the last few years, the number of this type of study has increased exponentially, but the results are not always reproducible due to experimental designs, low sample sizes and other methodological errors. In this field, meta-analysis techniques are becoming very popular tools to combine results across studies to increase statistical power and to resolve discrepancies in genetic association studies. A meta-analysis summarizes research findings, increases statistical power and enables the identification of genuine associations between genotypes and phenotypes. Meta-analysis techniques are increasingly used in GAS, but it is also increasing the amount of published meta-analysis containing different errors. Although there are several software packages that implement meta-analysis, none of them are specifically designed for genetic association studies and in most cases their use requires advanced programming or scripting expertise. We have developed MetaGenyo, a web tool for meta-analysis in GAS. MetaGenyo implements a complete and comprehensive workflow that can be executed in an easy-to-use environment without programming knowledge. MetaGenyo has been developed to guide users through the main steps of a GAS meta-analysis, covering Hardy-Weinberg test, statistical association for different genetic models, analysis of heterogeneity, testing for publication bias, subgroup analysis and robustness testing of the results. MetaGenyo is a useful tool to conduct comprehensive genetic association meta-analysis. The application is freely available at http://bioinfo.genyo.es/metagenyo/ .

Hemispheric specialization and creative thinking: a meta-analytic review of lateralization of creativity

NARCIS (Netherlands)

Mihov, K.M.; Denzler, M.; Förster, J.

2010-01-01

In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the

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

Science.gov (United States)

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

2018-01-01

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

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

Science.gov (United States)

Shaked, Michal; Yirmiya, Nurit

2004-01-01

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

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).

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

A meta-analysis of motivational interviewing process: Technical, relational, and conditional process models of change.

Science.gov (United States)

Magill, Molly; Apodaca, Timothy R; Borsari, Brian; Gaume, Jacques; Hoadley, Ariel; Gordon, Rebecca E F; Tonigan, J Scott; Moyers, Theresa

2018-02-01

In the present meta-analysis, we test the technical and relational hypotheses of Motivational Interviewing (MI) efficacy. We also propose an a priori conditional process model where heterogeneity of technical path effect sizes should be explained by interpersonal/relational (i.e., empathy, MI Spirit) and intrapersonal (i.e., client treatment seeking status) moderators. A systematic review identified k = 58 reports, describing 36 primary studies and 40 effect sizes (N = 3,025 participants). Statistical methods calculated the inverse variance-weighted pooled correlation coefficient for the therapist to client and the client to outcome paths across multiple target behaviors (i.e., alcohol use, other drug use, other behavior change). Therapist MI-consistent skills were correlated with more client change talk (r = .55, p technical hypothesis was supported. Specifically, proportion MI consistency was related to higher proportion change talk (r = .11, p = .004) and higher proportion change talk was related to reductions in risk behavior at follow up (r = -.16, p technical hypothesis path effect sizes was partially explained by inter- and intrapersonal moderators. This meta-analysis provides additional support for the technical hypothesis of MI efficacy; future research on the relational hypothesis should occur in the field rather than in the context of clinical trials. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Interval estimation of the overall treatment effect in a meta-analysis of a few small studies with zero events

NARCIS (Netherlands)

Pateras, Konstantinos; Nikolakopoulos, Stavros; Mavridis, Dimitris; Roes, Kit C.B.

2018-01-01

When a meta-analysis consists of a few small trials that report zero events, accounting for heterogeneity in the (interval) estimation of the overall effect is challenging. Typically, we predefine meta-analytical methods to be employed. In practice, data poses restrictions that lead to deviations

Exercise and Bone Density: Meta-Analysis

National Research Council Canada - National Science Library

Kelley, George A; Sharpe-Kelley, Kristi

2007-01-01

...% in both men and women, (2) when conducting meta-analytic research, either the original metric or standardized effect size can be used when analyzing data dealing with the effects of exercise on BMD in adults, (3...

Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: comparing meta and mega analytical approaches for data pooling

Science.gov (United States)

Kochunov, Peter; Jahanshad, Neda; Sprooten, Emma; Nichols, Thomas E.; Mandl, René C.; Almasy, Laura; Booth, Tom; Brouwer, Rachel M.; Curran, Joanne E.; de Zubicaray, Greig I.; Dimitrova, Rali; Duggirala, Ravi; Fox, Peter T.; Hong, L. Elliot; Landman, Bennett A.; Lemaitre, Hervé; Lopez, Lorna; Martin, Nicholas G.; McMahon, Katie L.; Mitchell, Braxton D.; Olvera, Rene L.; Peterson, Charles P.; Starr, John M.; Sussmann, Jessika E.; Toga, Arthur W.; Wardlaw, Joanna M.; Wright, Margaret J.; Wright, Susan N.; Bastin, Mark E.; McIntosh, Andrew M.; Boomsma, Dorret I.; Kahn, René S.; den Braber, Anouk; de Geus, Eco JC; Deary, Ian J.; Hulshoff Pol, Hilleke E.; Williamson, Douglas E.; Blangero, John; van ’t Ent, Dennis; Thompson, Paul M.; Glahn, David C.

2014-01-01

Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9–85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large “mega-family”. We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability. PMID:24657781

Comparing bona fide psychotherapies of depression in adults with two meta-analytical approaches.

Directory of Open Access Journals (Sweden)

Sarah R Braun

Full Text Available OBJECTIVE: Despite numerous investigations, the question whether all bona fide treatments of depression are equally efficacious in adults has not been sufficiently answered. METHOD: We applied two different meta-analytical techniques (conventional meta-analysis and mixed treatment comparisons. Overall, 53 studies with 3,965 patients, which directly compared two or more bona fide psychotherapies in a randomized trial, were included. Meta-analyses were conducted regarding five different types of outcome measures. Additionally, the influence of possible moderators was examined. RESULTS: Direct comparisons of cognitive behavior therapy, behavior activation therapy, psychodynamic therapy, interpersonal therapy, and supportive therapies versus all other respective treatments indicated that at the end of treatment all treatments but supportive therapies were equally efficacious whereas there was some evidence that supportive therapies were somewhat less efficacious than all other treatments according to patient self-ratings and clinical significance. At follow-up no significant differences were present. Age, gender, comorbid mental disorders, and length of therapy session were found to moderate efficacy. Cognitive behavior therapy was superior in studies where therapy sessions lasted 90 minutes or longer, behavior activation therapy was more efficacious when therapy sessions lasted less than 90 minutes. Mixed treatment comparisons indicated no statistically significant differences in treatment efficacy but some interesting trends. CONCLUSIONS: This study suggests that there might be differential effects of bona fide psychotherapies which should be examined in detail.

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

Science.gov (United States)

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.

Determining if disease management saves money: an introduction to meta-analysis.

Science.gov (United States)

Linden, Ariel; Adams, John L

2007-06-01

Disease management (DM) programmes have long been promoted as a major medical cost-saving mechanism, even though the scant research that exists on the topic has provided conflicting results. In a 2004 literature review, the Congressional Budget Office stated that 'there is insufficient evidence to conclude that disease management programs can generally reduce the overall cost of health care services'. To address this question more accurately, a meta-analysis was warranted. Meta-analysis is the quantitative technique used to pool the results of many studies on the same topic and summarize them statistically. This method is also quite suitable for individual DM firms to assess whether their programmes are effective at the aggregate level. This paper describes the elements of a rigorous meta-analytic process and discusses potential biases. A hypothetical DM organization is then evaluated with a specific emphasis on medical cost-savings, simulating a case in which different populations are served, evaluation methodologies are employed, and diseases are managed.

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

NARCIS (Netherlands)

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

2015-01-01

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

CD147/EMMPRIN overexpression and prognosis in cancer: A systematic review and meta-analysis

OpenAIRE

Xin, Xiaoyan; Zeng, Xianqin; Gu, Huajian; Li, Min; Tan, Huaming; Jin, Zhishan; Hua, Teng; Shi, Rui; Wang, Hongbo

2016-01-01

CD147/EMMPRIN (extracellular matrix metalloproteinase inducer) plays an important role in tumor progression and a number of studies have suggested that it is an indicator of tumor prognosis. This current meta-analysis systematically reevaluated the predictive potential of CD147/EMMPRIN in various cancers. We searched PubMed and Embase databases to screen the literature. Fixed-effect and random-effect meta-analytical techniques were used to correlate CD147 expression with outcome measures. A t...

Hemispheric Specialization and Creative Thinking: A Meta-Analytic Review of Lateralization of Creativity

Science.gov (United States)

Mihov, Konstantin M.; Denzler, Markus; Forster, Jens

2010-01-01

In the last two decades research on the neurophysiological processes of creativity has found contradicting results. Whereas most research suggests right hemisphere dominance in creative thinking, left-hemisphere dominance has also been reported. The present research is a meta-analytic review of the literature to establish how creative thinking…

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.

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)

Neuroanatomic changes and their association with cognitive decline in mild cognitive impairment: a meta-analysis

OpenAIRE

Nickl-Jockschat, Thomas; Kleiman, Alexandra; Schulz, Jörg B.; Schneider, Frank; Laird, Angela R.; Fox, Peter T.; Eickhoff, Simon B.; Reetz, Kathrin

2011-01-01

Mild cognitive impairment (MCI) is an acquired syndrome characterised by cognitive decline not affecting activities of daily living. Using a quantitative meta-analytic approach, we aimed to identify consistent neuroanatomic correlates of MCI and how they are related to cognitive dysfunction. The meta-analysis enrols 22 studies, involving 917 MCI (848 amnestic MCI) patients and 809 healthy controls. Only studies investigating local changes in grey matter and reporting whole-brain results in st...

Who benefits from supported employment: a meta-analytic study.

LENUS (Irish Health Repository)

Campbell, Kikuko

2012-02-01

AIMS: This meta-analysis sought to identify which subgroups of clients with severe mental illness (SMI) benefited from evidence-based supported employment. METHODS: We used meta-analysis to pool the samples from 4 randomized controlled trials comparing the Individual Placement and Support (IPS) model of supported employment to well-regarded vocational approaches using stepwise models and brokered services. Meta-analysis was used to determine the magnitude of effects for IPS\\/control group differences within specific client subgroups (defined by 2 work history, 7 sociodemographic, and 8 clinical variables) on 3 competitive employment outcomes (obtaining a job, total weeks worked, and job tenure). RESULTS: The findings strongly favored IPS, with large effect sizes across all outcomes: 0.96 for job acquisition, 0.79 for total weeks worked, and 0.74 for job tenure. Overall, 90 (77%) of the 117 effect sizes calculated for the 39 subgroups exceeded 0.70, and all 117 favored IPS. CONCLUSIONS: IPS produces better competitive employment outcomes for persons with SMI than alternative vocational programs regardless of background demographic, clinical, and employment characteristics.

Visualizing the flow of evidence in network meta-analysis and characterizing mixed treatment comparisons.

Science.gov (United States)

König, Jochem; Krahn, Ulrike; Binder, Harald

2013-12-30

Network meta-analysis techniques allow for pooling evidence from different studies with only partially overlapping designs for getting a broader basis for decision support. The results are network-based effect estimates that take indirect evidence into account for all pairs of treatments. The results critically depend on homogeneity and consistency assumptions, which are sometimes difficult to investigate. To support such evaluation, we propose a display of the flow of evidence and introduce new measures that characterize the structure of a mixed treatment comparison. Specifically, a linear fixed effects model for network meta-analysis is considered, where the network estimates for two treatments are linear combinations of direct effect estimates comparing these or other treatments. The linear coefficients can be seen as the generalization of weights known from classical meta-analysis. We summarize properties of these coefficients and display them as a weighted directed acyclic graph, representing the flow of evidence. Furthermore, measures are introduced that quantify the direct evidence proportion, the mean path length, and the minimal parallelism of mixed treatment comparisons. The graphical display and the measures are illustrated for two published network meta-analyses. In these applications, the proposed methods are seen to render transparent the process of data pooling in mixed treatment comparisons. They can be expected to be more generally useful for guiding and facilitating the validity assessment in network meta-analysis. Copyright © 2013 John Wiley & Sons, Ltd.

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

MetaMeta: integrating metagenome analysis tools to improve taxonomic profiling.

Science.gov (United States)

Piro, Vitor C; Matschkowski, Marcel; Renard, Bernhard Y

2017-08-14

Many metagenome analysis tools are presently available to classify sequences and profile environmental samples. In particular, taxonomic profiling and binning methods are commonly used for such tasks. Tools available among these two categories make use of several techniques, e.g., read mapping, k-mer alignment, and composition analysis. Variations on the construction of the corresponding reference sequence databases are also common. In addition, different tools provide good results in different datasets and configurations. All this variation creates a complicated scenario to researchers to decide which methods to use. Installation, configuration and execution can also be difficult especially when dealing with multiple datasets and tools. We propose MetaMeta: a pipeline to execute and integrate results from metagenome analysis tools. MetaMeta provides an easy workflow to run multiple tools with multiple samples, producing a single enhanced output profile for each sample. MetaMeta includes a database generation, pre-processing, execution, and integration steps, allowing easy execution and parallelization. The integration relies on the co-occurrence of organisms from different methods as the main feature to improve community profiling while accounting for differences in their databases. In a controlled case with simulated and real data, we show that the integrated profiles of MetaMeta overcome the best single profile. Using the same input data, it provides more sensitive and reliable results with the presence of each organism being supported by several methods. MetaMeta uses Snakemake and has six pre-configured tools, all available at BioConda channel for easy installation (conda install -c bioconda metameta). The MetaMeta pipeline is open-source and can be downloaded at: https://gitlab.com/rki_bioinformatics .

Angry Birds, Angry Children, and Angry Meta-Analysts: A Reanalysis.

Science.gov (United States)

Furuya-Kanamori, Luis; Doi, Suhail A R

2016-05-01

Ferguson's (2015a) meta-analysis assessed a very important and controversial topic about children's mental health and video games. In response to the concerns raised by researchers about the appropriateness of the meta-analytical methods used by Ferguson; we decided to reanalyze the data and discuss two major misconceptions about meta-analysis. We argue that partial correlations can (and should) be meta-analyzed instead of zero-order bivariate correlations if the predictors included in the partial correlation represent a similar construct. We also discuss the fallacy by which the conventional meta-analytical model assumes that the studies' effect sizes came into being according to the same random effect construct used by the analysis. Our replication results using partial correlations, standardized (valid and reliable) outcomes, and an improved meta-analytical model (that does not assume a random effect is the mechanism of data generation) confirmed the main results of Ferguson's meta-analysis. There was a significant yet very small effect on aggressive behavior of exposure to both general, rp = 0.062, 95% CI [0.012, 0.112], and violent, rp = 0.055, 95% CI [0.019, 0.091], video games. A very small effect was seen on reduced prosocial behavior, but this was only in the general video game exposure category, rp = 0.072, 95% CI [0.045, 0.100]. © The Author(s) 2016.

Impairment of sperm DNA methylation in male infertility: a meta-analytic study.

Science.gov (United States)

Santi, D; De Vincentis, S; Magnani, E; Spaggiari, G

2017-07-01

Considering the widespread use of assisted reproductive techniques (ART), DNA methylation of specific genes involved in spermatogenesis achieves increasingly clinical relevance, representing a possible explanation of increased incidence of syndromes related to genomic imprinting in medically assisted pregnancies. Several trials suggested a relationship between male sub-fertility and sperm DNA methylation, although its weight on seminal parameters alteration is still a matter of debate. To evaluate whether aberrant sperm DNA methylation of imprinted genes is associated with impaired sperm parameters. Meta-analysis of controlled clinical trials evaluating imprinted genes sperm DNA methylation comparing men with idiopathic infertility to fertile controls. Twenty-four studies were included, allowing a meta-analytic evaluation for H19, MEST, SNRPN, and LINE-1. When a high heterogeneity of the results was demonstrated, the random effect model was used. H19 methylation levels resulted significantly lower in 879 infertile compared with 562 fertile men (7.53%, 95% CI: 5.14-9.93%, p male infertility is associated with altered sperm methylation at H19, MEST, and SNRPN. Although its role in infertility remains unclear, sperm DNA methylation could be associated with the epigenetic risk in ART. In this setting, before proposing this analysis in clinical practice, an accurate identification of the most representative genes and a cost-effectiveness evaluation should be assessed in ad hoc prospective studies. © 2017 American Society of Andrology and European Academy of Andrology.

Estimation of the biserial correlation and its sampling variance for use in meta-analysis.

Science.gov (United States)

Jacobs, Perke; Viechtbauer, Wolfgang

2017-06-01

Meta-analyses are often used to synthesize the findings of studies examining the correlational relationship between two continuous variables. When only dichotomous measurements are available for one of the two variables, the biserial correlation coefficient can be used to estimate the product-moment correlation between the two underlying continuous variables. Unlike the point-biserial correlation coefficient, biserial correlation coefficients can therefore be integrated with product-moment correlation coefficients in the same meta-analysis. The present article describes the estimation of the biserial correlation coefficient for meta-analytic purposes and reports simulation results comparing different methods for estimating the coefficient's sampling variance. The findings indicate that commonly employed methods yield inconsistent estimates of the sampling variance across a broad range of research situations. In contrast, consistent estimates can be obtained using two methods that appear to be unknown in the meta-analytic literature. A variance-stabilizing transformation for the biserial correlation coefficient is described that allows for the construction of confidence intervals for individual coefficients with close to nominal coverage probabilities in most of the examined conditions. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Atheists and Agnostics Are More Reflective than Religious Believers: Four Empirical Studies and a Meta-Analysis

Science.gov (United States)

Pennycook, Gordon; Ross, Robert M.; Koehler, Derek J.; Fugelsang, Jonathan A.

2016-01-01

Individual differences in the mere willingness to think analytically has been shown to predict religious disbelief. Recently, however, it has been argued that analytic thinkers are not actually less religious; rather, the putative association may be a result of religiosity typically being measured after analytic thinking (an order effect). In light of this possibility, we report four studies in which a negative correlation between religious belief and performance on analytic thinking measures is found when religious belief is measured in a separate session. We also performed a meta-analysis on all previously published studies on the topic along with our four new studies (N = 15,078, k = 31), focusing specifically on the association between performance on the Cognitive Reflection Test (the most widely used individual difference measure of analytic thinking) and religious belief. This meta-analysis revealed an overall negative correlation (r) of -.18, 95% CI [-.21, -.16]. Although this correlation is modest, self-identified atheists (N = 133) scored 18.7% higher than religiously affiliated individuals (N = 597) on a composite measure of analytic thinking administered across our four new studies (d = .72). Our results indicate that the association between analytic thinking and religious disbelief is not caused by a simple order effect. There is good evidence that atheists and agnostics are more reflective than religious believers. PMID:27054566

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

Science.gov (United States)

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

2017-10-02

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

Comparison of Estimation Techniques for Vibro-Acoustic Transfer Path Analysis

Directory of Open Access Journals (Sweden)

Paulo Eduardo França Padilha

2006-01-01

Full Text Available Vibro-acoustic Transfer Path Analysis (TPA is a tool to evaluate the contribution of different energy propagation paths between a source and a receiver, linked to each other by a number of connections. TPA is typically used to quantify and rank the relative importance of these paths in a given frequency band, determining the most significant one to the receiver. Basically, two quantities have to be determined for TPA: the operational forces at each transfer path and the Frequency Response Functions (FRF of these paths. The FRF are obtained either experimentally or analytically, and the influence of the mechanical impedance of the source can be taken into account or not. The operational forces can be directly obtained from measurements using force transducers or indirectly estimated from auxiliary response measurements. Two methods to obtain the operational forces indirectly – the Complex Stiffness Method (CSM and the Matrix Inversion Method (MIM – associated with two possible configurations to determine the FRF – including and excluding the source impedance – are presented and discussed in this paper. The effect of weak and strong coupling among the paths is also commented considering the techniques previously presented. The main conclusion is that, with the source removed, CSM gives more accurate results. On the other hand, with the source present, MIM is preferable. In the latter case, CSM should be used only if there is a high impedance mismatch between the source and the receiver. Both methods are not affected by a higher or lower degree of coupling among the transfer paths.

A Comparative Meta-Analysis of 5E and Traditional Approaches in Turkey

Science.gov (United States)

Anil, Özgür; Batdi, Veli

2015-01-01

The aim of this study is to compare the 5E learning model with traditional learning methods in terms of their effect on students' academic achievement, retention and attitude scores. In this context, the meta-analytic method known as the "analysis of analyses" was used and a review undertaken of the studies and theses (N = 14) executed…

Analysis of construction dynamic plan using fuzzy critical path method

Directory of Open Access Journals (Sweden)

Kurij Kazimir V.

2014-01-01

Full Text Available Critical Path Method (CPM technique has become widely recognized as valuable tool for the planning and scheduling large construction projects. The aim of this paper is to present an analytical method for finding the Critical Path in the precedence network diagram where the duration of each activity is represented by a trapezoidal fuzzy number. This Fuzzy Critical Path Method (FCPM uses a defuzzification formula for trapezoidal fuzzy number and applies it on the total float (slack time for each activity in the fuzzy precedence network to find the critical path. The method presented in this paper is very effective in determining the critical activities and finding the critical paths.

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.

The Effect of Brain Based Learning on Academic Achievement: A Meta-Analytical Study

Science.gov (United States)

Gozuyesil, Eda; Dikici, Ayhan

2014-01-01

This study's aim is to measure the effect sizes of the quantitative studies that examined the effectiveness of brain-based learning on students' academic achievement and to examine with the meta-analytical method if there is a significant difference in effect in terms of the factors of education level, subject matter, sampling size, and the…

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

A Meta-Analytic Review of Moral Licensing

NARCIS (Netherlands)

Blanken, Irene; van de Ven, Niels; Zeelenberg, Marcel

2015-01-01

Moral licensing refers to the effect that when people initially behave in a moral way, they are later more likely to display behaviors that are immoral, unethical, or otherwise problematic. We provide a state-of-the-art overview of moral licensing by conducting a meta-analysis of 91 studies (7,397

A meta-analytic review of moral licensing

NARCIS (Netherlands)

Blanken, I.; van de Ven, N.; Zeelenberg, M.

2015-01-01

Moral licensing refers to the effect that when people initially behave in a moral way, they are later more likely to display behaviors that are immoral, unethical, or otherwise problematic. We provide a state-of-the-art overview of moral licensing by conducting a meta-analysis of 91 studies (7,397

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.

Efficacy of computer technology-based HIV prevention interventions: a meta-analysis.

Science.gov (United States)

Noar, Seth M; Black, Hulda G; Pierce, Larson B

2009-01-02

To conduct a meta-analysis of computer technology-based HIV prevention behavioral interventions aimed at increasing condom use among a variety of at-risk populations. Systematic review and meta-analysis of existing published and unpublished studies testing computer-based interventions. Meta-analytic techniques were used to compute and aggregate effect sizes for 12 randomized controlled trials that met inclusion criteria. Variables that had the potential to moderate intervention efficacy were also tested. The overall mean weighted effect size for condom use was d = 0.259 (95% confidence interval = 0.201, 0.317; Z = 8.74, P partners, and incident sexually transmitted diseases. In addition, interventions were significantly more efficacious when they were directed at men or women (versus mixed sex groups), utilized individualized tailoring, used a Stages of Change model, and had more intervention sessions. Computer technology-based HIV prevention interventions have similar efficacy to more traditional human-delivered interventions. Given their low cost to deliver, ability to customize intervention content, and flexible dissemination channels, they hold much promise for the future of HIV prevention.

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

Science.gov (United States)

Levitt, Heidi M

2018-05-01

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

Reaffirmed limitations of meta-analytic methods in the study of mild traumatic brain injury: a response to Rohling et al.

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Bigler, Erin D; Farrer, Thomas J; Pertab, Jon L; James, Kelly; Petrie, Jo Ann; Hedges, Dawson W

2013-01-01

In 2009 Pertab, James, and Bigler published a critique of two prior meta-analyses by Binder, Rohling, and Larrabee (1997) and Frencham, Fox, and Maybery (2005) that showed small effect size difference at least 3 months post-injury in individuals who had sustained a mild traumatic brain injury (mTBI). The Binder et al. and Frencham et al. meta-analyses have been widely cited as showing no lasting effect of mTBI. In their critique Pertab et al. (2009) point out many limitations of these two prior meta-analyses, demonstrating that depending on how inclusion/exclusion criteria were defined different meta-analytic findings occur, some supporting the persistence of neuropsychological impairments beyond 3 months. Rohling et al. (2011) have now critiqued Pertab et al. (2009). Herein we respond to the Rolling et al. (2011) critique reaffirming the original findings of Pertab et al. (2009), providing additional details concerning the flaws in prior meta-analytic mTBI studies and the effects on neuropsychological performance.

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...

The TEACCH program for children and adults with autism: a meta-analysis of intervention studies.

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Virues-Ortega, Javier; Julio, Flávia M; Pastor-Barriuso, Roberto

2013-12-01

The intervention program for autism known as Treatment and Education of Autistic and Related Communication Handicapped Children (TEACCH) is considered an emerging practice for autism. In the present study we used state-of-the-art meta-analytical procedures to examine the pooled clinical effects of TEACCH in a variety of outcomes. A total of 13 studies were selected for meta-analysis totaling 172 individuals with autism exposed to TEACCH. Standardized measures of perceptual, motor, adaptive, verbal and cognitive skills were identified as treatment outcomes. We used inverse-variance weighted random effects meta-analysis supplemented with quality assessment, sensitivity analysis, meta-regression, and heterogeneity and publication bias tests. The results suggested that TEACCH effects on perceptual, motor, verbal and cognitive skills were of small magnitude in the meta-analyzed studies. Effects over adaptive behavioral repertoires including communication, activities of daily living, and motor functioning were within the negligible to small range. There were moderate to large gains in social behavior and maladaptive behavior. The effects of the TEACCH program were not moderated by aspects of the intervention such as duration (total weeks), intensity (hours per week), and setting (home-based vs. center-based). While the present meta-analysis provided limited support for the TEACCH program as a comprehensive intervention, our results should be considered exploratory owing to the limited pool of studies available. © 2013.

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...

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

A meta-analysis of fear appeals: implications for effective public health campaigns.

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Witte, K; Allen, M

2000-10-01

The fear appeal literature is examined in a comprehensive synthesis using meta-analytical techniques. The meta-analysis suggests that strong fear appeals produce high levels of perceived severity and susceptibility, and are more persuasive than low or weak fear appeals. The results also indicate that fear appeals motivate adaptive danger control actions such as message acceptance and maladaptive fear control actions such as defensive avoidance or reactance. It appears that strong fear appeals and high-efficacy messages produce the greatest behavior change, whereas strong fear appeals with low-efficacy messages produce the greatest levels of defensive responses. Future directions and practical implications are provided.

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

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

2016-04-01

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

A review of cognitive conflicts research: a meta-analytic study of prevalence and relation to symptoms

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Montesano A

2015-12-01

Full Text Available Adrián Montesano,1 María Angeles López-González,2 Luis Angel Saúl,2 Guillem Feixas1 1Department of Personality, Assessment and Psychological Treatments, University of Barcelona, Barcelona, 2Department of Personality, Assessment and Psychological Treatments, Faculty of Psychology, National Distance Education University, Madrid, Spain Abstract: Recent research has highlighted the role of implicative dilemmas in a variety of clinical conditions. These dilemmas are a type of cognitive conflict, in which different aspects of the self are countered in such a way that a desired change in a personal dimension (eg, symptom improvement may be hindered by the need of personal coherence in another dimension. The aim of this study was to summarize, using a meta-analytical approach, the evidence relating to the presence and the level of this conflict, as well as its relationship with well-being, in various clinical samples. A systematic review using multiple electronic databases found that out of 37 articles assessed for eligibility, nine fulfilled the inclusion criteria for meta-analysis. Random effects model was applied when computing mean effect sizes and testing for heterogeneity level. Statistically significant associations were observed between the clinical status and the presence of dilemmas, as well as level of conflict across several clinical conditions. Likewise, the level of conflict was associated with symptom severity. Results highlighted the clinical relevance and the transdiagnostic nature of implicative dilemmas. Keywords: implicative dilemmas, cognitive conflicts, intrapersonal conflicts, meta-analysis

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

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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.

Self-Determination Theory Applied to Health Contexts: A Meta-Analysis.

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Ng, Johan Y Y; Ntoumanis, Nikos; Thøgersen-Ntoumani, Cecilie; Deci, Edward L; Ryan, Richard M; Duda, Joan L; Williams, Geoffrey C

2012-07-01

Behavior change is more effective and lasting when patients are autonomously motivated. To examine this idea, we identified 184 independent data sets from studies that utilized self-determination theory (SDT; Deci & Ryan, 2000) in health care and health promotion contexts. A meta-analysis evaluated relations between the SDT-based constructs of practitioner support for patient autonomy and patients' experience of psychological need satisfaction, as well as relations between these SDT constructs and indices of mental and physical health. Results showed the expected relations among the SDT variables, as well as positive relations of psychological need satisfaction and autonomous motivation to beneficial health outcomes. Several variables (e.g., participants' age, study design) were tested as potential moderators when effect sizes were heterogeneous. Finally, we used path analyses of the meta-analyzed correlations to test the interrelations among the SDT variables. Results suggested that SDT is a viable conceptual framework to study antecedents and outcomes of motivation for health-related behaviors. © The Author(s) 2012.

A meta-analytically derived nomological network of procrastination

NARCIS (Netherlands)

Eerde, van W.

2003-01-01

This meta-analysis contains the correlations of 121 studies examining the relation between procrastination and personality variables, motives, affect, and performance. The largest negative effect sizes were found in relation to conscientiousness and self-efficacy, and the largest positive relation

An overview of meta-analysis for clinicians

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Lee, Young Ho

2018-01-01

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

An overview of meta-analysis for clinicians.

Science.gov (United States)

Lee, Young Ho

2018-03-01

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

A meta-analytic review of psychological treatments for tinnitus.

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Andersson, G; Lyttkens, L

1999-08-01

Meta-analysis is a technique of combining results from different trials in order to obtain estimates of effects across studies. Meta-analysis has, as yet, rarely been used in audiological research. The aim of this paper was to conduct a meta-analysis on psychological treatment of tinnitus. The outcomes of 18 studies, including a total of 24 samples and up to 700 subjects, were included and coded. Included were studies on cognitive/cognitive-behavioural treatment, relaxation, hypnosis, biofeedback, educational sessions and problem-solving. Effect sizes for perceived tinnitus loudness, annoyance, negative affect (e.g. depression) and sleep problems were calculated for randomized controlled studies, pre-post-treatment design studies and follow-up results. Results showed strong to moderate effects on tinnitus annoyance for controlled studies (d = 0.86), pre-post designs (d = 0.5) and at follow-up (d = 0.48). Results on tinnitus loudness were weaker and disappeared at follow-up. Lower effect sizes were also obtained for measures of negative affect and sleep problems. Exploratory analyses revealed that cognitive-behavioural treatments were more effective on ratings of annoyance in the controlled studies. It is concluded that psychological treatment for tinnitus is effective, but that aspects such as depression and sleep problems may need to be targeted in future studies.

A Two-Stage Approach to Synthesizing Covariance Matrices in Meta-Analytic Structural Equation Modeling

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Cheung, Mike W. L.; Chan, Wai

2009-01-01

Structural equation modeling (SEM) is widely used as a statistical framework to test complex models in behavioral and social sciences. When the number of publications increases, there is a need to systematically synthesize them. Methodology of synthesizing findings in the context of SEM is known as meta-analytic SEM (MASEM). Although correlation…

Gardening is beneficial for health: A meta-analysis.

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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.

Meta-Analysis of Workplace Physical Activity Interventions

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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

Violent media and hostile appraisals: A meta-analytic review.

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Bushman, Brad J

2016-11-01

Hostile people tend to view the world as a hostile place. Although there are individual differences in hostile world-views, situational factors can also play a role. For example, scenes of violence in the mass media might influence people to view the world as a hostile place. This meta-analysis aggregates, for the first time, all studies that have investigated the link between exposure to violent media and hostile appraisals (e.g., perceiving the ambiguous actions by others as aggressive actions). This meta-analysis included 37 independent studies involving 10,410 participants. The results showed a "small" to "moderate" sized average correlation between exposure to violent media and hostile appraisals (r +  = .20, 95%CI = .14, .26). Significant correlations were found in experimental, cross-sectional, and longitudinal studies, indicating a triangulation of evidence. Effects were not correlated with participant gender. Effects were also stable over time. However, the link between exposure to violent media and hostile appraisals was positively related to age, perhaps because violent media can have cumulative effects over time. There was no evidence of publication bias. The findings from this meta-analysis are consistent with the General Aggression Model (e.g., Anderson, & Bushman, 2002; Annual Review of Psychology 53:27-51). These results compliment those from previous meta-analyses showing that violent media can increase aggressive thoughts, angry feelings, physiological arousal, and aggressive behavior. These findings also have practical significance, because people who view the world in a hostile manner are more likely to behave aggressively themselves. Aggr. Behav. 42:605-613, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A meta-analysis of personality and workplace safety: addressing unanswered questions.

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Beus, Jeremy M; Dhanani, Lindsay Y; McCord, Mallory A

2015-03-01

[Correction Notice: An Erratum for this article was reported in Vol 100(2) of Journal of Applied Psychology (see record 2015-08139-001). Table 3 contained formatting errors. Minus signs used to indicate negative statistical estimates within the table were inadvertently changed to m-dashes. All versions of this article have been corrected.] The purpose of this meta-analysis was to address unanswered questions regarding the associations between personality and workplace safety by (a) clarifying the magnitude and meaning of these associations with both broad and facet-level personality traits, (b) delineating how personality is associated with workplace safety, and (c) testing the relative importance of personality in comparison to perceptions of the social context of safety (i.e., safety climate) in predicting safety-related behavior. Our results revealed that whereas agreeableness and conscientiousness were negatively associated with unsafe behaviors, extraversion and neuroticism were positively associated with them. Of these traits, agreeableness accounted for the largest proportion of explained variance in safety-related behavior and openness to experience was unrelated. At the facet level, sensation seeking, altruism, anger, and impulsiveness were all meaningfully associated with safety-related behavior, though sensation seeking was the only facet that demonstrated a stronger relationship than its parent trait (i.e., extraversion). In addition, meta-analytic path modeling supported the theoretical expectation that personality's associations with accidents are mediated by safety-related behavior. Finally, although safety climate perceptions accounted for the majority of explained variance in safety-related behavior, personality traits (i.e., agreeableness, conscientiousness, neuroticism) still accounted for a unique and substantive proportion of the explained variance. Taken together, these results substantiate the value of considering personality traits as key

Bullying in the digital age: a critical review and meta-analysis of cyberbullying research among youth.

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Kowalski, Robin M; Giumetti, Gary W; Schroeder, Amber N; Lattanner, Micah R

2014-07-01

Although the Internet has transformed the way our world operates, it has also served as a venue for cyberbullying, a serious form of misbehavior among youth. With many of today's youth experiencing acts of cyberbullying, a growing body of literature has begun to document the prevalence, predictors, and outcomes of this behavior, but the literature is highly fragmented and lacks theoretical focus. Therefore, our purpose in the present article is to provide a critical review of the existing cyberbullying research. The general aggression model is proposed as a useful theoretical framework from which to understand this phenomenon. Additionally, results from a meta-analytic review are presented to highlight the size of the relationships between cyberbullying and traditional bullying, as well as relationships between cyberbullying and other meaningful behavioral and psychological variables. Mixed effects meta-analysis results indicate that among the strongest associations with cyberbullying perpetration were normative beliefs about aggression and moral disengagement, and the strongest associations with cyberbullying victimization were stress and suicidal ideation. Several methodological and sample characteristics served as moderators of these relationships. Limitations of the meta-analysis include issues dealing with causality or directionality of these associations as well as generalizability for those meta-analytic estimates that are based on smaller sets of studies (k cyberbullying (over and above traditional bullying) on key behavioral and psychological outcomes. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Multivariate Meta-Analysis of Genetic Association Studies: A Simulation Study.

Directory of Open Access Journals (Sweden)

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

Psychosocial work environment and mental health--a meta-analytic review.

Science.gov (United States)

Stansfeld, Stephen; Candy, Bridget

2006-12-01

To clarify the associations between psychosocial work stressors and mental ill health, a meta-analysis of psychosocial work stressors and common mental disorders was undertaken using longitudinal studies identified through a systematic literature review. The review used a standardized search strategy and strict inclusion and quality criteria in seven databases in 1994-2005. Papers were identified from 24,939 citations covering social determinants of health, 50 relevant papers were identified, 38 fulfilled inclusion criteria, and 11 were suitable for a meta-analysis. The Comprehensive Meta-analysis Programme was used for decision authority, decision latitude, psychological demands, and work social support, components of the job-strain and iso-strain models, and the combination of effort and reward that makes up the effort-reward imbalance model and job insecurity. Cochran's Q statistic assessed the heterogeneity of the results, and the I2 statistic determined any inconsistency between studies. Job strain, low decision latitude, low social support, high psychological demands, effort-reward imbalance, and high job insecurity predicted common mental disorders despite the heterogeneity for psychological demands and social support among men. The strongest effects were found for job strain and effort-reward imbalance. This meta-analysis provides robust consistent evidence that (combinations of) high demands and low decision latitude and (combinations of) high efforts and low rewards are prospective risk factors for common mental disorders and suggests that the psychosocial work environment is important for mental health. The associations are not merely explained by response bias. The impact of work stressors on common mental disorders differs for women and men.

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

NARCIS (Netherlands)

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

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

Personality and team performance: a meta analysis

NARCIS (Netherlands)

Peeters, Miranda A.G.; van Tuijl, Harrie F.J.M.; Rutte, Christel G.; Reymen, Isabelle

2006-01-01

Using a meta-analytical procedure, the relationship between team composition in terms of the Big-Five personality traits (trait elevation and variability) and team performance were researched. The number of teams upon which analyses were performed ranged from 106 to 527. For the total sample,

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.

The Sleeper Effect in Persuasion: A Meta-Analytic Review

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Kumkale, G. Tarcan; Albarracín, Dolores

2009-01-01

A meta-analysis of the available judgment and memory data on the sleeper effect in persuasion is presented. According to this effect, when people receive a communication associated with a discounting cue, such as a noncredible source, they are less persuaded immediately after exposure than they are later in time. Findings from this meta-analysis indicate that recipients of discounting cues were more persuaded over time when the message arguments and the cue had a strong initial impact. In addition, the increase in persuasion was stronger when recipients of discounting cues had higher ability or motivation to think about the message and received the discounting cue after the message. These results are discussed in light of classic and contemporary models of attitudes and persuasion. PMID:14717653

Intrinsic motivation and extrinsic incentives jointly predict performance: a 40-year meta-analysis.

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Cerasoli, Christopher P; Nicklin, Jessica M; Ford, Michael T

2014-07-01

More than 4 decades of research and 9 meta-analyses have focused on the undermining effect: namely, the debate over whether the provision of extrinsic incentives erodes intrinsic motivation. This review and meta-analysis builds on such previous reviews by focusing on the interrelationship among intrinsic motivation, extrinsic incentives, and performance, with reference to 2 moderators: performance type (quality vs. quantity) and incentive contingency (directly performance-salient vs. indirectly performance-salient), which have not been systematically reviewed to date. Based on random-effects meta-analytic methods, findings from school, work, and physical domains (k = 183, N = 212,468) indicate that intrinsic motivation is a medium to strong predictor of performance (ρ = .21-45). The importance of intrinsic motivation to performance remained in place whether incentives were presented. In addition, incentive salience influenced the predictive validity of intrinsic motivation for performance: In a "crowding out" fashion, intrinsic motivation was less important to performance when incentives were directly tied to performance and was more important when incentives were indirectly tied to performance. Considered simultaneously through meta-analytic regression, intrinsic motivation predicted more unique variance in quality of performance, whereas incentives were a better predictor of quantity of performance. With respect to performance, incentives and intrinsic motivation are not necessarily antagonistic and are best considered simultaneously. Future research should consider using nonperformance criteria (e.g., well-being, job satisfaction) as well as applying the percent-of-maximum-possible (POMP) method in meta-analyses. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Practicality of diversion path analysis

International Nuclear Information System (INIS)

Murphey, W.M.; Schleter, J.C.

1974-07-01

One can define the safeguards system for nuclear material as the set of all protective actions taken to prevent or to deter attempts to divert nuclear material to unauthorized use. Maintenance of effective safeguards requires a program for routine assessment of plant safeguards systems in terms of their capabilities to satisfy safeguards aims. Plant internal control systems provide capabilities for detection of unprevented diversion and can provide assurance that diversion has not occurred. A procedure called Diversion Path Analysis (DPA) enables routine assessment of the capabilities of internal control systems in this regard and identification of safeguards problem areas in a plant. A framework for safeguards system design is also provided which will allow flexibility to accommodate individual plant circumstances while maintaining acceptable diversion detection capability. The steps of the procedure are described and the practicality of the analytical method is shown by referring to a demonstration test for a high throughput process where plant personnel were major participants. The boundary conditions for the demonstration case are given, along with some conclusions about the general procedure. (U.S.)

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/.

Chinese Culture, Homosexuality Stigma, Social Support and Condom Use: A Path Analytic Model.

Science.gov (United States)

Liu, Hongjie; Feng, Tiejian; Ha, Toan; Liu, Hui; Cai, Yumao; Liu, Xiaoli; Li, Jian

2011-01-01

PURPOSE: The objective of this study was to examine the interrelationships among individualism, collectivism, homosexuality-related stigma, social support, and condom use among Chinese homosexual men. METHODS: A cross-sectional study using the respondent-driven sampling approach was conducted among 351 participants in Shenzhen, China. Path analytic modeling was used to analyze the interrelationships. RESULTS: The results of path analytic modeling document the following statistically significant associations with regard to homosexuality: (1) higher levels of vertical collectivism were associated with higher levels of public stigma [β (standardized coefficient) = 0.12] and self stigma (β = 0.12); (2) higher levels of vertical individualism were associated with higher levels self stigma (β = 0.18); (3) higher levels of horizontal individualism were associated with higher levels of public stigma (β = 0.12); (4) higher levels of self stigma were associated with higher levels of social support from sexual partners (β = 0.12); and (5) lower levels of public stigma were associated with consistent condom use (β = -0.19). CONCLUSIONS: The findings enhance our understanding of how individualist and collectivist cultures influence the development of homosexuality-related stigma, which in turn may affect individuals' decisions to engage in HIV-protective practices and seek social support. Accordingly, the development of HIV interventions for homosexual men in China should take the characteristics of Chinese culture into consideration.

Chinese Culture, Homosexuality Stigma, Social Support and Condom Use: A Path Analytic Model

Science.gov (United States)

Liu, Hongjie; Feng, Tiejian; Ha, Toan; Liu, Hui; Cai, Yumao; Liu, Xiaoli; Li, Jian

2011-01-01

Purpose The objective of this study was to examine the interrelationships among individualism, collectivism, homosexuality-related stigma, social support, and condom use among Chinese homosexual men. Methods A cross-sectional study using the respondent-driven sampling approach was conducted among 351 participants in Shenzhen, China. Path analytic modeling was used to analyze the interrelationships. Results The results of path analytic modeling document the following statistically significant associations with regard to homosexuality: (1) higher levels of vertical collectivism were associated with higher levels of public stigma [β (standardized coefficient) = 0.12] and self stigma (β = 0.12); (2) higher levels of vertical individualism were associated with higher levels self stigma (β = 0.18); (3) higher levels of horizontal individualism were associated with higher levels of public stigma (β = 0.12); (4) higher levels of self stigma were associated with higher levels of social support from sexual partners (β = 0.12); and (5) lower levels of public stigma were associated with consistent condom use (β = −0.19). Conclusions The findings enhance our understanding of how individualist and collectivist cultures influence the development of homosexuality-related stigma, which in turn may affect individuals’ decisions to engage in HIV-protective practices and seek social support. Accordingly, the development of HIV interventions for homosexual men in China should take the characteristics of Chinese culture into consideration. PMID:21731850

Motivation Interventions in Education: A Meta-Analytic Review

Science.gov (United States)

Lazowski, Rory A.; Hulleman, Chris S.

2016-01-01

This meta-analysis provides an extensive and organized summary of intervention studies in education that are grounded in motivation theory. We identified 74 published and unpublished papers that experimentally manipulated an independent variable and measured an authentic educational outcome within an ecologically valid educational context. Our…

Meta-Analysis at Middle Age: A Personal History

Science.gov (United States)

Glass, Gene V.

2015-01-01

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

Effects of Innovative Science and Mathematics Teaching on Student Attitudes and Achievement: A Meta-Analytic Study

NARCIS (Netherlands)

Savelsbergh, E.R.; Prins, G.T.; Rietbergen, C.; Fechner, S.; Vaessen, B.E.; Draijer, J.M.; Bakker, A.

2016-01-01

Many teaching approaches have been tried to improve student attitudes and achievement in science and mathematics education. Achievement effects have been synthesized, but a systematic overview of attitude effects is missing. This study provides a meta analytic review based on 56 publications

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.

A meta-analytic review on treatment dropout in child and adolescent outpatient mental health care

NARCIS (Netherlands)

de Haan, A.M.; Boon, A.E.; de Jong, J.T.V.M.; Hoeve, M.; Vermeiren, R.R.J.M.

2013-01-01

A large proportion (28% up to 75%) of the treatments in youth mental health care results in premature termination (dropout). It is important to gain knowledge of the determinants of dropout because it can have very severe consequences. The aim of our meta-analytic review was to provide an overview

Meta-analytic Review of Memory Impairment in Behavioral Variant Frontotemporal Dementia.

Science.gov (United States)

Poos, Jackie M; Jiskoot, Lize C; Papma, Janne M; van Swieten, John C; van den Berg, Esther

2018-03-19

A meta-analysis of the extent, nature and pattern of memory performance in behavioral variant frontotemporal dementia (bvFTD). Multiple observational studies have challenged the relative sparing of memory in bvFTD as stated in the current diagnostic criteria. We performed a meta-analytic review covering the period 1967 to February 2017 of case-control studies on episodic memory in bvFTD versus control participants (16 studies, 383 patients, 603 control participants), and patients with bvFTD versus those with Alzheimer's disease (AD) (20 studies, 452 bvFTD, 874 AD). Differences between both verbal and non-verbal working memory, episodic memory learning and recall, and recognition memory were examined. Data were extracted from the papers and combined into a common metric measure of effect, Hedges' d. Patients with bvFTD show large deficits in memory performance compared to controls (Hedges' d -1.10; 95% confidence interval [CI] [-1.23, -0.95]), but perform significantly better than patients with AD (Hedges' d 0.85; 95% CI [0.69, 1.03]). Learning and recall tests differentiate best between patients with bvFTD and AD (p<.01). There is 37-62% overlap in test scores between the two groups. This study points to memory disorders in patients with bvFTD, with performance at an intermediate level between controls and patients with AD. This indicates that, instead of being an exclusion criterion for bvFTD diagnosis, memory deficits should be regarded as a potential integral part of the clinical spectrum. (JINS, 2018, 24, 1-13).

Likelihood-Based Clustering of Meta-Analytic SROC Curves

Science.gov (United States)

Holling, Heinz; Bohning, Walailuck; Bohning, Dankmar

2012-01-01

Meta-analysis of diagnostic studies experience the common problem that different studies might not be comparable since they have been using a different cut-off value for the continuous or ordered categorical diagnostic test value defining different regions for which the diagnostic test is defined to be positive. Hence specificities and…

A Meta-Analytic Review of Social Identification and Health in Organizational Contexts.

Science.gov (United States)

Steffens, Niklas K; Haslam, S Alexander; Schuh, Sebastian C; Jetten, Jolanda; van Dick, Rolf

2017-11-01

We provide a meta-analytical review examining two decades of work on the relationship between individuals' social identifications and health in organizations (102 effect sizes, k = 58, N = 19,799). Results reveal a mean-weighted positive association between organizational identification and health ( r = .21, T = .14). Analysis identified a positive relationship for both workgroup ( r = .21) and organizational identification ( r = .21), and in studies using longitudinal/experimental ( r = .13) and cross-sectional designs ( r = .22). The relationship is stronger (a) for indicators of the presence of well-being ( r = .27) than absence of stress ( r = .18), (b) for psychological ( r = .23) than physical health ( r = .16), (c) to the extent that identification is shared among group members, and (d) as the proportion of female participants in a sample decreases. Overall, results indicate that social identifications in organizations are positively associated with health but that there is also substantial variation in effect size strength. We discuss implications for theory and practice and outline a roadmap for future research.

Meta-analysis to predict the effects of metabolizable amino acids on dairy cattle performance.

Science.gov (United States)

Lean, I J; de Ondarza, M B; Sniffen, C J; Santos, J E P; Griswold, K E

2018-01-01

Meta-analytic methods were used to determine statistical relationships between metabolizable AA supplies and milk protein yield, milk protein percentage, and milk yield in lactating dairy cows. Sixty-three research publications (258 treatment means) were identified through a search of published literature using 3 search engines and met the criteria for inclusion in this meta-analysis. The Cornell Net Carbohydrate and Protein System (CNCPS) version 6.5 was used to determine dietary nutrient parameters including metabolizable AA. Two approaches were used to analyze the data. First, mixed models were fitted to determine whether explanatory variables predicted responses. Each mixed model contained a global intercept, a random intercept for each experiment, and data were weighted by the inverse of the SEM squared. The second analysis approach used classical effect size meta-analytical evaluation of responses to treatment weighted by the inverse of the treatment variance and with a random effect of treatment nested within experiment. Regardless of the analytical approach, CNCPS-predicted metabolizable Met (g/d) was associated with milk protein percentage and yield. Milk yield was positively associated with CNCPS-predicted metabolizable His, Leu, Trp, Thr, and nonessential AA (g/d). Milk true protein yield was also associated with CNCPS-predicted metabolizable Leu (g/d). Predicted metabolizable Lysine (g/d) did not increase responses in production outcomes. However, mean metabolizable Lys supply was less than typically recommended and the change with treatment was minimal (157 vs. 162 g; 6.36 vs. 6.38% metabolizable protein). Experiments based solely on Lys or Met interventions were excluded from the study database. It is possible that the inclusion of these experiments may have provided additional insight into the effect of these AA on responses. This meta-analysis supports other research indicating a positive effect of Met and His as co-limiting AA in dairy cows and

Organizational Culture and Organizational Effectiveness: A Meta-Analytic Investigation of the Competing Values Framework's Theoretical Suppositions

Science.gov (United States)

Hartnell, Chad A.; Ou, Amy Yi; Kinicki, Angelo

2011-01-01

We apply Quinn and Rohrbaugh's (1983) competing values framework (CVF) as an organizing taxonomy to meta-analytically test hypotheses about the relationship between 3 culture types and 3 major indices of organizational effectiveness (employee attitudes, operational performance [i.e., innovation and product and service quality], and financial…

The reasonable woman standard: a meta-analytic review of gender differences in perceptions of sexual harassment.

Science.gov (United States)

Blumenthal, J A

1998-02-01

Courts and legislatures have begun to develop the "reasonable woman standard" (RWS) as a criterion for deciding sexual harassment trials. This standard rests on assumptions of a "wide divergence" between the perceptions of men and women when viewing social-sexual behavior that may be considered harassing. Narrative reviews of the literature on such perceptions have suggested that these assumptions are only minimally supported. To test these assumptions quantitatively, a meta-analytic review was conducted that assessed the size, stability, and moderators of gender differences in perceptions of sexual harassment. The effect of the actor's status relative to the target also was evaluated meta-analytically, as one alternative to the importance of gender effects. Results supported the claims of narrative reviews for a relatively small gender effect, and draw attention to the status effect. In discussing legal implications of the present findings, earlier claims are echoed suggesting caution in establishing the reasonable woman standard, and one alternative to the RWS, the "reasonable victim standard," is discussed.

The Efficacy of Mindfulness-Based Interventions in Primary Care: A Meta-Analytic Review.

Science.gov (United States)

Demarzo, Marcelo M P; Montero-Marin, Jesús; Cuijpers, Pim; Zabaleta-del-Olmo, Edurne; Mahtani, Kamal R; Vellinga, Akke; Vicens, Caterina; López-del-Hoyo, Yolanda; García-Campayo, Javier

2015-11-01

Positive effects have been reported after mindfulness-based interventions (MBIs) in diverse clinical and nonclinical populations. Primary care is a key health care setting for addressing common chronic conditions, and an effective MBI designed for this setting could benefit countless people worldwide. Meta-analyses of MBIs have become popular, but little is known about their efficacy in primary care. Our aim was to investigate the application and efficacy of MBIs that address primary care patients. We performed a meta-analytic review of randomized controlled trials addressing the effect of MBIs in adult patients recruited from primary care settings. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) and Cochrane guidelines were followed. Effect sizes were calculated with the Hedges g in random effects models. The meta-analyses were based on 6 trials having a total of 553 patients. The overall effect size of MBI compared with a control condition for improving general health was moderate (g = 0.48; P = .002), with moderate heterogeneity (I(2) = 59; P .05). Although the number of randomized controlled trials applying MBIs in primary care is still limited, our results suggest that these interventions are promising for the mental health and quality of life of primary care patients. We discuss innovative approaches for implementing MBIs, such as complex intervention and stepped care. © 2015 Annals of Family Medicine, Inc.

Extremal and Degree Conditions for Path Extendability in Digraphs

NARCIS (Netherlands)

Zhang, Zan-Bo; Zhang, Xiaoyan; Broersma, Hajo; Lou, Dingjun

2017-01-01

In the study of cycles and paths, the meta-conjecture of Bondy that sufficient conditions for Hamiltonicity often imply pancyclicity has motivated research on the existence of cycles and paths of many lengths. Hendry further introduced the stronger concepts of cycle extendability and path

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.

Testing moderation in network meta-analysis with individual participant data

Science.gov (United States)

Dagne, Getachew A.; Brown, C. Hendricks; Howe, George; Kellam, Sheppard G.; Liu, Lei

2016-01-01

Summary Meta-analytic methods for combining data from multiple intervention trials are commonly used to estimate the effectiveness of an intervention. They can also be extended to study comparative effectiveness, testing which of several alternative interventions is expected to have the strongest effect. This often requires network meta-analysis (NMA), which combines trials involving direct comparison of two interventions within the same trial and indirect comparisons across trials. In this paper, we extend existing network methods for main effects to examining moderator effects, allowing for tests of whether intervention effects vary for different populations or when employed in different contexts. In addition, we study how the use of individual participant data (IPD) may increase the sensitivity of NMA for detecting moderator effects, as compared to aggregate data NMA that employs study-level effect sizes in a meta-regression framework. A new network meta-analysis diagram is proposed. We also develop a generalized multilevel model for NMA that takes into account within- and between-trial heterogeneity, and can include participant-level covariates. Within this framework we present definitions of homogeneity and consistency across trials. A simulation study based on this model is used to assess effects on power to detect both main and moderator effects. Results show that power to detect moderation is substantially greater when applied to IPD as compared to study-level effects. We illustrate the use of this method by applying it to data from a classroom-based randomized study that involved two sub-trials, each comparing interventions that were contrasted with separate control groups. PMID:26841367

Voxelwise meta-analysis of gray matter abnormalities in dementia with Lewy bodies

International Nuclear Information System (INIS)

Zhong, JianGuo; Pan, PingLei; Dai, ZhenYu; Shi, HaiCun

2014-01-01

Highlights: • We first report the meta-analyses of GM anomalies by VBM studies in DLB. • Lateral temporal/insular and lenticular nucleus/insular cortex atrophy were detected. • A characteristic pattern of GM changes underpinned DLB. - Abstract: Background: Increasing neuroimaging studies have revealed brain gray matter (GM) atrophy by voxel-based morphometry (VBM) studies in patients with dementia with Lewy bodies (DLB) relative to healthy controls. However, the spatial localization of GM abnormalities reported in the existing studies is heterogeneous. Here, we aimed to investigate concurrence across VBM studies to help clarify the structural abnormalities underpinning this condition. Methods: A systematic search for VBM studies of DLB patients and healthy controls published in PubMed database from January 2000 to March 2014 was conducted. A quantitative meta-analysis of whole-brain VBM studies in DLB patients and healthy controls was performed by means of Anisotropic Effect Size version of Signed Differential Mapping (AES-SDM) software package. Results: Seven studies comprising 218 DLB patients and 219 healthy controls were included in the present study. Compared to healthy subjects, the patients group showed consistent decreased GM in right lateral temporal/insular cortex and left lenticular nucleus/insular cortex. The results remained largely unchanged in the following jackknife sensitivity analyses. Meta-regression analysis indicated an increased probability of finding brain atrophy in left superior temporal gyrus in patients with lower MMSE scores. Conclusions: The present meta-analysis quantitatively demonstrates a characteristic pattern of GM alternations that contributed to the understanding of pathophysiology underlying DLB. Future studies will benefit from employing meta-analytical comparisons to other dementia subtypes with solid evidence to extend these findings.

Voxelwise meta-analysis of gray matter abnormalities in dementia with Lewy bodies

Energy Technology Data Exchange (ETDEWEB)

Zhong, JianGuo; Pan, PingLei [Department of Neurology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China); Dai, ZhenYu [Department of Radiology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China); Shi, HaiCun, E-mail: yc3yhcshi@gmail.com [Department of Neurology, Affiliated Yancheng Hospital of Southeast University, Yancheng (China)

2014-10-15

Highlights: • We first report the meta-analyses of GM anomalies by VBM studies in DLB. • Lateral temporal/insular and lenticular nucleus/insular cortex atrophy were detected. • A characteristic pattern of GM changes underpinned DLB. - Abstract: Background: Increasing neuroimaging studies have revealed brain gray matter (GM) atrophy by voxel-based morphometry (VBM) studies in patients with dementia with Lewy bodies (DLB) relative to healthy controls. However, the spatial localization of GM abnormalities reported in the existing studies is heterogeneous. Here, we aimed to investigate concurrence across VBM studies to help clarify the structural abnormalities underpinning this condition. Methods: A systematic search for VBM studies of DLB patients and healthy controls published in PubMed database from January 2000 to March 2014 was conducted. A quantitative meta-analysis of whole-brain VBM studies in DLB patients and healthy controls was performed by means of Anisotropic Effect Size version of Signed Differential Mapping (AES-SDM) software package. Results: Seven studies comprising 218 DLB patients and 219 healthy controls were included in the present study. Compared to healthy subjects, the patients group showed consistent decreased GM in right lateral temporal/insular cortex and left lenticular nucleus/insular cortex. The results remained largely unchanged in the following jackknife sensitivity analyses. Meta-regression analysis indicated an increased probability of finding brain atrophy in left superior temporal gyrus in patients with lower MMSE scores. Conclusions: The present meta-analysis quantitatively demonstrates a characteristic pattern of GM alternations that contributed to the understanding of pathophysiology underlying DLB. Future studies will benefit from employing meta-analytical comparisons to other dementia subtypes with solid evidence to extend these findings.

Learning About Love: A Meta-Analytic Study of Individually-Oriented Relationship Education Programs for Adolescents and Emerging Adults.

Science.gov (United States)

Simpson, David M; Leonhardt, Nathan D; Hawkins, Alan J

2018-03-01

Despite recent policy initiatives and substantial federal funding of individually oriented relationship education programs for youth, there have been no meta-analytic reviews of this growing field. This meta-analytic study draws on 17 control-group studies and 13 one-group/pre-post studies to evaluate the effectiveness of relationship education programs on adolescents' and emerging adults' relationship knowledge, attitudes, and skills. Overall, control-group studies produced a medium effect (d = .36); one-group/pre-post studies also produced a medium effect (d = .47). However, the lack of studies with long-term follow-ups of relationship behaviors in the young adult years is a serious weakness in the field, limiting what we can say about the value of these programs for helping youth achieve their aspirations for healthy romantic relationships and stable marriages.

Affective empathy in schizophrenia: a meta-analysis.

Science.gov (United States)

Bonfils, Kelsey A; Lysaker, Paul H; Minor, Kyle S; Salyers, Michelle P

2016-08-01

Affective empathy, or the emotional response one has to the experiences or emotional states of others, contributes to relationship-maintaining behaviors and is key in fostering social connections, yet no work has synthesized the body of literature for people with schizophrenia. The aim of the present meta-analysis was to determine the extent to which those diagnosed with schizophrenia experience deficits in affective empathy. A literature search was conducted of studies examining empathy. Data were analyzed using a random effects meta-analytic model with Hedges' g standardized mean difference effect size. Individuals with schizophrenia exhibited significant, medium deficits in affective empathy (k=37). Measurement type moderated the affective empathy deficit such that performance-based measures showed larger schizophrenia group deficits than self-report measures. Consistent, significant deficits in affective empathy were found comparing people with schizophrenia to healthy controls, especially when using performance-based assessments. The medium effect suggests an important role for empathy in the realm of social cognitive research, and points to the need for further investigation of measurement techniques and associations with functional outcomes. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Acquisition Path Analysis as a Collaborative Activity

International Nuclear Information System (INIS)

Nakao, A.; Grundule, R.; Gushchyn, K.; El Gebaly, A.; Higgy, R.; Tsvetkov, I.; Mandl, W.

2015-01-01

In the International Atomic Energy Agency, acquisition path analysis (APA) is indispensable to safeguards implementation. It is an integral part of both State evaluation process and the development of State level safeguards approaches, all performed through ongoing collaborative analysis of all available safeguards relevant information by State evaluation groups (SEG) with participation of other contributors, as required. To perform comprehensive State evaluation, to develop and revise State-level safeguards approaches, and to prepare annual implementation plans, the SEG in its collaborative analysis follows accepted safeguards methodology and guidance. In particular, the guide ''Performing Acquisition Path Analysis for the Development of a State-level Safeguards Approach for a State with a CSA'' is used. This guide identifies four major steps of the APA process: 1. Consolidating information about the State's past, present and planned nuclear fuel cycle-related capabilities and infrastructure; 2. Identifying and visually presenting technically plausible acquisition paths for the State; 3. Assessing acquisition path steps (State's technical capabilities and possible actions) along the identified acquisition paths; and 4. Assessing the time needed to accomplish each identified technically plausible acquisition path for the State. The paper reports on SEG members' and other contributors' experience with APA when following the above steps, including the identification of plausible acquisition pathways, estimation of time frames for all identified steps and determination of the time needed to accomplish each acquisition path. The difficulties that the SEG encountered during the process of performing the APA are also addressed. Feedback in the form of practical suggestions for improving the clarity of the acquisition path step assessment forms and a proposal for software support are also included. (author)

What Limits the Encoding Effect of Note-Taking? A Meta-Analytic Examination

Science.gov (United States)

Kobayashi, K.

2005-01-01

Previous meta-analyses indicate that the overall encoding effect of note-taking is positive but modest. This meta-analysis of 57 note-taking versus no note-taking comparison studies explored what limits the encoding effect by examining the moderating influence of seven variables: intervention, schooling level, presentation mode and length, test…

A meta-analytic review of gender differences in perceptions of sexual harassment.

Science.gov (United States)

Rotundo, M; Nguyen, D H; Sackett, P R

2001-10-01

Research on gender differences in perceptions of sexual harassment informs an ongoing legal debate regarding the use of a reasonable person standard instead of a reasonable woman standard to evaluate sexual harassment claims. The authors report a meta-analysis of 62 studies of gender differences in harassment perceptions. An earlier quantitative review combined all types of social-sexual behaviors for a single meta-analysis; the purpose of this study was to investigate whether the magnitude of the female-male difference varies by type of behavior. An overall standardized mean difference of 0.30 was found, suggesting that women perceive a broader range of social-sexual behaviors as harassing. However, the meta-analysis also found that the female-male difference was larger for behaviors that involve hostile work environment harassment, derogatory attitudes toward women, dating pressure, or physical sexual contact than sexual propositions or sexual coercion.

A Meta-Analytic Review of Tactile-Cued Self-Monitoring Interventions Used by Students in Educational Settings

Science.gov (United States)

McDougall, Dennis; Ornelles, Cecily; Mersberg, Kawika; Amona, Kekama

2015-01-01

In this meta-analytic review, we critically evaluate procedures and outcomes from nine intervention studies in which students used tactile-cued self-monitoring in educational settings. Findings suggest that most tactile-cued self-monitoring interventions have moderate to strong effects, have emerged only recently, and have not yet achieved the…

How important are work-family support policies? A meta-analytic investigation of their effects on employee outcomes.

Science.gov (United States)

Butts, Marcus M; Casper, Wendy J; Yang, Tae Seok

2013-01-01

This meta-analysis examines relationships between work-family support policies, which are policies that provide support for dependent care responsibilities, and employee outcomes by developing a conceptual model detailing the psychological mechanisms through which policy availability and use relate to work attitudes. Bivariate results indicated that availability and use of work-family support policies had modest positive relationships with job satisfaction, affective commitment, and intentions to stay. Further, tests of differences in effect sizes showed that policy availability was more strongly related to job satisfaction, affective commitment, and intentions to stay than was policy use. Subsequent meta-analytic structural equation modeling results indicated that policy availability and use had modest effects on work attitudes, which were partially mediated by family-supportive organization perceptions and work-to-family conflict, respectively. Additionally, number of policies and sample characteristics (percent women, percent married-cohabiting, percent with dependents) moderated the effects of policy availability and use on outcomes. Implications of these findings and directions for future research on work-family support policies are discussed. PsycINFO Database Record (c) 2013 APA, all rights reserved.

ADHD and personality: a meta-analytic review

OpenAIRE

Gomez, R.; Corr, P. J.

2014-01-01

We report a meta-analysis of up to 40 data sets that examined the personality dimensions in the Five-Factor Model (FFM) and the integrated Five-Factor Model (IFFM) in relation to ADHD symptom domains of inattention (IA) and hyperactivity/impulsivity (HI). The IFFM incorporated the dimensions of other personality models (in particular, those of Eysenck, Tellegen, and Cloninger, as well as the FFM). Major findings were: (1) IA and HI were both associated with low conscientious inhibition/consci...

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

Science.gov (United States)

Kriston, Levente; Meister, Ramona

2014-03-01

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

Early Start DENVER Model: A Meta - analysis

Directory of Open Access Journals (Sweden)

Jane P. Canoy

2015-11-01

Full Text Available Each child with Autism Spectrum Disorder has different symptoms, skills and types of impairment or disorder with other children. This is why the word “spectrum” is included in this disorder. Eapen, Crncec, and Walter, 2013 claimed that there was an emerging evidence that early interventions gives the greatest capacity of child’s development during their first years of life as “brain plasticity” are high during this period. With this, the only intervention program model for children as young as 18 months that has been validated in a randomized clinical trial is “Early Start Denver Model” (ESDM. This study aimed to determine the effectiveness of the outcome of “Early Start Denver Model” (ESDM towards young children with Autism Spectrum Disorders. This study made use of meta-analysis method. In this study, the researcher utilized studies related to “Early Start Denver Model (ESDM” which is published in a refereed journal which are all available online. There were five studies included which totals 149 children exposed to ESDM. To examine the “pooled effects” of ESDM in a variety of outcomes, a meta-analytic procedure was performed after the extraction of data of the concrete outcomes. Comprehensive Meta Analysis Version 3.3.070 was used to analyze the data.  The effectiveness of the outcome of “Early Start Denver Model” towards young children with Autism Spectrum Disorders (ASD highly depends on the intensity of intervention and the younger child age. This study would provide the basis in effectively implementing an early intervention to children with autism such as the “Early Start Denver Model” (ESDM that would show great outcome effects to those children that has “Autism Spectrum Disorder”.

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

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…

STRATEGIC INFORMATION SYSTEMS PLANNING IN THE BANKING SECTOR—A PATH ANALYTIC MODEL STUDY IN THE INDIAN CONTEXT

Directory of Open Access Journals (Sweden)

A. M. Rawani

2002-01-01

Full Text Available This paper presents a path analytic model showing the cause and effect relationships among various Information Systems (IS planning variables for the banking sector in India. In recent years, there has been an increased awareness among banks of the potential of Information Technology (IT and the use of information systems. Strategic information system planning (SISP becomes an important issue in the use of IS strategically. In India, banks have now started realizing the importance of SISP. In this study, 11 IS planning variables for the banking sector in India are examined and the influence of one over the other is investigated using path analysis. Data for the study are collected from 52 banks operating in India. The results of the study indicate that top management involvement in IS planning greatly influences the whole planning exercise. Moreover, top management involvement is higher when they foresee greater future impact of IS. The study also highlights the need and importance of user training in the banking sector. Change in the focus and orientation of user-training will make the users competent to conceive with innovative IS applications.

A framework for the meta-analysis of Bland-Altman studies based on a limits of agreement approach.

Science.gov (United States)

Tipton, Elizabeth; Shuster, Jonathan

2017-10-15

Bland-Altman method comparison studies are common in the medical sciences and are used to compare a new measure to a gold-standard (often costlier or more invasive) measure. The distribution of these differences is summarized by two statistics, the 'bias' and standard deviation, and these measures are combined to provide estimates of the limits of agreement (LoA). When these LoA are within the bounds of clinically insignificant differences, the new non-invasive measure is preferred. Very often, multiple Bland-Altman studies have been conducted comparing the same two measures, and random-effects meta-analysis provides a means to pool these estimates. We provide a framework for the meta-analysis of Bland-Altman studies, including methods for estimating the LoA and measures of uncertainty (i.e., confidence intervals). Importantly, these LoA are likely to be wider than those typically reported in Bland-Altman meta-analyses. Frequently, Bland-Altman studies report results based on repeated measures designs but do not properly adjust for this design in the analysis. Meta-analyses of Bland-Altman studies frequently exclude these studies for this reason. We provide a meta-analytic approach that allows inclusion of estimates from these studies. This includes adjustments to the estimate of the standard deviation and a method for pooling the estimates based upon robust variance estimation. An example is included based on a previously published meta-analysis. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

GWAMA: software for genome-wide association meta-analysis

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Mägi Reedik

2010-05-01

Full Text Available Abstract Background Despite the recent success of genome-wide association studies in identifying novel loci contributing effects to complex human traits, such as type 2 diabetes and obesity, much of the genetic component of variation in these phenotypes remains unexplained. One way to improving power to detect further novel loci is through meta-analysis of studies from the same population, increasing the sample size over any individual study. Although statistical software analysis packages incorporate routines for meta-analysis, they are ill equipped to meet the challenges of the scale and complexity of data generated in genome-wide association studies. Results We have developed flexible, open-source software for the meta-analysis of genome-wide association studies. The software incorporates a variety of error trapping facilities, and provides a range of meta-analysis summary statistics. The software is distributed with scripts that allow simple formatting of files containing the results of each association study and generate graphical summaries of genome-wide meta-analysis results. Conclusions The GWAMA (Genome-Wide Association Meta-Analysis software has been developed to perform meta-analysis of summary statistics generated from genome-wide association studies of dichotomous phenotypes or quantitative traits. Software with source files, documentation and example data files are freely available online at http://www.well.ox.ac.uk/GWAMA.

Does intergenerational transmission of trauma skip a generation? No meta-analytic evidence for tertiary traumatization with third generation of Holocaust survivors.

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Sagi-Schwartz, Abraham; van IJzendoorn, Marinus H; Bakermans-Kranenburg, Marian J

2008-06-01

In a series of meta-analyses with the second generation of Holocaust survivors, no evidence for secondary traumatization was found (Van IJzendoorn, Bakermans-Kranenburg, & Sagi-Schwartz, 2003). With regard to third generation traumatization, various reports suggest the presence of intergenerational transmission of trauma. Some scholars argue that intergenerational transmission of trauma might skip a generation. Therefore, we focus in this study on the transmission of trauma to the third generation offspring (the grandchildren) of the first generation's traumatic Holocaust experiences (referred to as "tertiary traumatization"), and we present a narrative review of the pertinent studies. Meta-analytic results of 13 non-clinical samples involving 1012 participants showed no evidence for tertiary traumatization in Holocaust survivor families. Our previous meta-analytic study on secondary traumatization and the present one on third generation's psychological consequences of the Holocaust indicate a remarkable resilience of profoundly traumatized survivors in their (grand-)parental roles.

Language and Verbal Short-Term Memory Skills in Children with Down Syndrome: A Meta-Analytic Review

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Naess, Kari-Anne B.; Lyster, Solveig-Alma Halaas; Hulme, Charles; Melby-Lervag, Monica

2011-01-01

This study presents a meta-analytic review of language and verbal short-term memory skills in children with Down syndrome. The study examines the profile of strengths and weaknesses in children with Down syndrome compared to typically developing children matched for nonverbal mental age. The findings show that children with Down syndrome have…

A taxonomy of integral reaction path analysis

Energy Technology Data Exchange (ETDEWEB)

Grcar, Joseph F.; Day, Marcus S.; Bell, John B.

2004-12-23

W. C. Gardiner observed that achieving understanding through combustion modeling is limited by the ability to recognize the implications of what has been computed and to draw conclusions about the elementary steps underlying the reaction mechanism. This difficulty can be overcome in part by making better use of reaction path analysis in the context of multidimensional flame simulations. Following a survey of current practice, an integral reaction flux is formulated in terms of conserved scalars that can be calculated in a fully automated way. Conditional analyses are then introduced, and a taxonomy for bidirectional path analysis is explored. Many examples illustrate the resulting path analysis and uncover some new results about nonpremixed methane-air laminar jets.

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…

The Consequences of Perceived Discrimination for Psychological Well-Being : A Meta-Analytic Review

NARCIS (Netherlands)

Schmitt, Michael T.; Branscombe, Nyla R.; Postmes, Tom; Garcia, Amber

In 2 meta-analyses, we examined the relationship between perceived discrimination and psychological well-being and tested a number of moderators of that relationship. In Meta-Analysis 1 (328 independent effect sizes, N = 144,246), we examined correlational data measuring both perceived

High versus low radioiodine activity in patients with differentiated thyroid cancer - A meta-analysis

Energy Technology Data Exchange (ETDEWEB)

Valachis, Antonis [Dept. of Oncology, Maelarsjukhuset., Eskilstuna (Sweden); Univ. of Uppsala,, (Sweden)], e-mail: Valachis@hotmail.com, Antonis.Valachis@akademiska.uu.se; Nearchou, Andreas [Dept, of Oncology, Maelarsjukhuset., Eskilstuna (Sweden); Univ. of Uppsala., Uppsala (Sweden)

2013-08-15

Background: The purpose of the meta-analysis was to estimate the effectiveness and toxicity of low activity radioiodine ablation versus high activity in patients with differentiated thyroid cancer (DTC). Design: A systematic review and meta-analysis was performed by including all randomized trials of low activity versus high activity radioiodine ablation after thyroidectomy. Standard meta-analytic procedures were used to analyze the study outcomes. Results: Ten trials were considered eligible and were further analyzed. The pooled risk ratio (RR) of having a successful ablation for an activity of 1100 MBq versus 3700 MBq (seven trials, 1772 patients) was 0.94 (95% CI 0.85 - 1.04, p-value 0.21). The RR for successful ablation when only thyroid hormone withdrawal was used (five trials, 1116 patients) was 0.87 (95% CI 0.72 - 1.06, p-value 0.17) and it was comparable to RR when only recombinant-human TSH (rec-hTSH) (two trials, 812 patients) was used (1.00, 95% CI 0.93 - 1.07, p-value 0.92). Salivary dysfunction, nausea, and neck pain were significantly more frequent among patients with higher dose for ablation. Conclusion: Our meta-analysis provides some evidence from randomized trials that a lower activity of radioiodine ablation is as effective as higher dose after surgery in patients with DTC with lower toxicity.

High versus low radioiodine activity in patients with differentiated thyroid cancer - A meta-analysis

International Nuclear Information System (INIS)

Valachis, Antonis; Nearchou, Andreas

2013-01-01

Background: The purpose of the meta-analysis was to estimate the effectiveness and toxicity of low activity radioiodine ablation versus high activity in patients with differentiated thyroid cancer (DTC). Design: A systematic review and meta-analysis was performed by including all randomized trials of low activity versus high activity radioiodine ablation after thyroidectomy. Standard meta-analytic procedures were used to analyze the study outcomes. Results: Ten trials were considered eligible and were further analyzed. The pooled risk ratio (RR) of having a successful ablation for an activity of 1100 MBq versus 3700 MBq (seven trials, 1772 patients) was 0.94 (95% CI 0.85 - 1.04, p-value 0.21). The RR for successful ablation when only thyroid hormone withdrawal was used (five trials, 1116 patients) was 0.87 (95% CI 0.72 - 1.06, p-value 0.17) and it was comparable to RR when only recombinant-human TSH (rec-hTSH) (two trials, 812 patients) was used (1.00, 95% CI 0.93 - 1.07, p-value 0.92). Salivary dysfunction, nausea, and neck pain were significantly more frequent among patients with higher dose for ablation. Conclusion: Our meta-analysis provides some evidence from randomized trials that a lower activity of radioiodine ablation is as effective as higher dose after surgery in patients with DTC with lower toxicity

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:.

A Key Event Path Analysis Approach for Integrated Systems

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Jingjing Liao

2012-01-01

Full Text Available By studying the key event paths of probabilistic event structure graphs (PESGs, a key event path analysis approach for integrated system models is proposed. According to translation rules concluded from integrated system architecture descriptions, the corresponding PESGs are constructed from the colored Petri Net (CPN models. Then the definitions of cycle event paths, sequence event paths, and key event paths are given. Whereafter based on the statistic results after the simulation of CPN models, key event paths are found out by the sensitive analysis approach. This approach focuses on the logic structures of CPN models, which is reliable and could be the basis of structured analysis for discrete event systems. An example of radar model is given to characterize the application of this approach, and the results are worthy of trust.

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…

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

DiversePathsJ: diverse shortest paths for bioimage analysis.

Science.gov (United States)

Uhlmann, Virginie; Haubold, Carsten; Hamprecht, Fred A; Unser, Michael

2018-02-01

We introduce a formulation for the general task of finding diverse shortest paths between two end-points. Our approach is not linked to a specific biological problem and can be applied to a large variety of images thanks to its generic implementation as a user-friendly ImageJ/Fiji plugin. It relies on the introduction of additional layers in a Viterbi path graph, which requires slight modifications to the standard Viterbi algorithm rules. This layered graph construction allows for the specification of various constraints imposing diversity between solutions. The software allows obtaining a collection of diverse shortest paths under some user-defined constraints through a convenient and user-friendly interface. It can be used alone or be integrated into larger image analysis pipelines. http://bigwww.epfl.ch/algorithms/diversepathsj. michael.unser@epfl.ch or fred.hamprecht@iwr.uni-heidelberg.de. Supplementary data are available at Bioinformatics online. © The Author(s) 2017. Published by Oxford University Press.

Psychological contract breach and outcomes: Combining meta-analysis and structural equation models.

Science.gov (United States)

Topa Cantisano, Gabriela; Morales Domínguez, J Francisco; Depolo, Marco

2008-08-01

In this study, meta-analytic procedures were used to examine the relationships between psychological contract perceived breach and certain outcome variables, such as organizational commitment, job satisfaction and organizational citizenship behaviours (OCB). Our review of the literature generated 41 independent samples in which perceived breach was used as a predictor of these personal and organizational outcomes. A medium effect size (ES) for desirable outcomes (job satisfaction, organizational commitment, organizational trust, OCB and performance) was obtained (r=-.35). For undesirable outcomes (neglect in role duties and intention to leave), ES were also medium (r=.31). When comparing attitudinal (job satisfaction, organizational commitment, organizational trust) and behavioural outcomes (OCB, neglect in role duties and performance), a stronger ES was found for attitudinal (r=-.24) than for behavioural outcomes (r=-.11). Potential moderator variables were examined, and it was found that they explained only a percentage of variability of primary studies. Structural equation analysis of the pooled meta-analytical correlation matrix indicated that the relationships of perceived breach with satisfaction, OCB, intention to leave and performance are fully mediated by organizational trust and commitment. Results are discussed in order to suggest theoretical and empirical implications.

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

Examining the Job-Related, Psychological, and Physical Outcomes of Workplace Sexual Harassment: A Meta-Analytic Review

Science.gov (United States)

Chan, Darius K-S.; Lam, Chun Bun; Chow, Suk Yee; Cheung, Shu Fai

2008-01-01

This study was designed to examine the job-related, psychological, and physical outcomes of sexual harassment in the workplace. Using a meta-analytic approach, we analyzed findings from 49 primary studies, with a total sample size of 89,382, to obtain estimates of the population mean effect size of the association between sexual harassment and…

Phonon interference control of atomic-scale metamirrors, meta-absorbers, and heat transfer through crystal interfaces

Science.gov (United States)

Kosevich, Yu. A.; Potyomina, L. G.; Darinskii, A. N.; Strelnikov, I. A.

2018-03-01

The paper theoretically studies the possibility of using the effects of phonon interference between paths through different interatomic bonds for the control of phonon heat transfer through internal crystal interfaces and for the design of phonon metamirrors and meta-absorbers. These metamirrors and meta-absorbers are considered to be defect nanolayers of atomic-scale thicknesses embedded in a crystal. Several analytically solvable three-dimensional lattice-dynamics models of the phonon metamirrors and meta-absorbers at the internal crystal planes are described. It is shown that due to destructive interference in the two or more phonon paths, the internal crystal planes, fully or partially filled with weakly bound or heavy-isotope defect atoms, can completely reflect or completely absorb phonons at the transmission antiresonances, whose wavelengths are larger than the effective thickness of the metamirror or meta-absorber. Due to cooperative superradiant effect, the spectral widths of the two-path interference antiresonances for the plane waves are given by the square of partial filling fraction in the defect crystal plane. Our analysis reveals that the presence of two or more phonon paths plays the dominant role in the emergence of the transmission antiresonances in phonon scattering at the defect crystal planes and in reduction of the thermal interface conductance in comparison with the Fano-resonance concept. We study analytically phonon transmission through internal crystal plane in a model cubic lattice of Si-like atoms, partially filled with Ge-like defect atoms. Such a plane can serve as interference phonon metamirror with the transmission antiresonances in the vicinities of eigenmode frequencies of Ge-like defect atoms in the terahertz frequency range. We predict the extraordinary phonon transmission induced by the two-path constructive interference of the lattice waves in resonance with the vibrations of rare host atoms, periodically distributed in the

Conventional vs. e-learning in nursing education: A systematic review and meta-analysis.

Science.gov (United States)

Voutilainen, Ari; Saaranen, Terhi; Sormunen, Marjorita

2017-03-01

By and large, in health professions training, the direction of the effect of e-learning, positive or negative, strongly depends on the learning outcome in question as well as on learning methods which e-learning is compared to. In nursing education, meta-analytically generated knowledge regarding the comparisons between conventional and e-learning is scarce. The aim of this review is to discover the size of the effect of e-learning on learning outcomes in nursing education and to assess the quality of studies in which e-learning has been compared to conventional learning. A systematic search of six electronic databases, PubMed, Ovid MEDLINE®, CINAHL (EBSCOhost), Cochrane Library, PsycINFO, and ERIC, was conducted in order to identify relevant peer-reviewed English language articles published between 2011 and 2015. The quality of the studies included as well as the risk of bias in each study was assessed. A random-effects meta-analysis was performed to generate a pooled mean difference in the learning outcome. Altogether, 10 studies were eligible for the quality assessment and meta-analysis. Nine studies were evaluated as good quality studies, but not without a risk of bias. Performance bias caused a high risk in nearly all the studies. In the meta-analysis, an e-learning method resulted in test scores that were, on average, five points higher than a conventional method on a 0-100 scale. Heterogeneity between the studies was very large. The size and direction of the effect of a learning method on learning outcomes appeared to be strongly situational. We suggest that meta-regressions should be performed instead of basic meta-analyses in order to reveal factors that cause variation in the learning outcomes of nursing education. It might be necessary to perform separate meta-analyses between e-learning interventions aimed at improving nursing knowledge and those aimed at improving nursing skills. Copyright © 2016 Elsevier Ltd. All rights reserved.

Relationships among neurocognition, symptoms and functioning in patients with schizophrenia: a path-analytic approach for associations at baseline and following 24 weeks of antipsychotic drug therapy

Directory of Open Access Journals (Sweden)

Keefe Richard SE

2009-07-01

Full Text Available Abstract Background Neurocognitive impairment and psychiatric symptoms have been associated with deficits in psychosocial and occupational functioning in patients with schizophrenia. This post-hoc analysis evaluates the relationships among cognition, psychopathology, and psychosocial functioning in patients with schizophrenia at baseline and following sustained treatment with antipsychotic drugs. Methods Data were obtained from a clinical trial assessing the cognitive effects of selected antipsychotic drugs in patients with schizophrenia. Patients were randomly assigned to 24 weeks of treatment with olanzapine (n = 159, risperidone (n = 158, or haloperidol (n = 97. Psychosocial functioning was assessed with the Heinrichs-Carpenter Quality of Life Scale [QLS], cognition with a standard battery of neurocognitive tests; and psychiatric symptoms with the Positive and Negative Syndrome Scale [PANSS]. A path-analytic approach was used to evaluate the effects of changes in cognitive functioning on subdomains of quality of life, and to determine whether such effects were direct or mediated via changes in psychiatric symptoms. Results At baseline, processing speed affected functioning mainly indirectly via negative symptoms. Positive symptoms also affected functioning at baseline although independent of cognition. At 24 weeks, changes in processing speed affected changes in functioning both directly and indirectly via PANSS negative subscale scores. Positive symptoms no longer contributed to the path-analytic models. Although a consistent relationship was observed between processing speed and the 3 functional domains, variation existed as to whether the paths were direct and/or indirect. Working memory and verbal memory did not significantly contribute to any of the path-analytic models studied. Conclusion Processing speed demonstrated direct and indirect effects via negative symptoms on three domains of functioning as measured by the QLS at baseline and

A Meta-Analytic Review of Studies of the Effectiveness of Small-Group Learning Methods on Statistics Achievement

Science.gov (United States)

Kalaian, Sema A.; Kasim, Rafa M.

2014-01-01

This meta-analytic study focused on the quantitative integration and synthesis of the accumulated pedagogical research in undergraduate statistics education literature. These accumulated research studies compared the academic achievement of students who had been instructed using one of the various forms of small-group learning methods to those who…

Transaction cost determinants and ownership-based entry mode choice: a meta-analytical review

OpenAIRE

Hongxin Zhao; Yadong Luo; Taewon Suh

2004-01-01

Entry mode choice is a critical ingredient of international entry strategies, and has been voluminously examined in the field. The findings, however, are very mixed, especially with respect to transaction-cost-related factors in determining the ownership-based entry mode choice. This study conducted a meta-analysis to quantitatively summarize the literature and empirically generalize more conclusive findings. Based on the 106 effect sizes of 38 empirical studies, the meta-analysis shows that ...

MetaSeq: privacy preserving meta-analysis of sequencing-based association studies.

Science.gov (United States)

Singh, Angad Pal; Zafer, Samreen; Pe'er, Itsik

2013-01-01

Human genetics recently transitioned from GWAS to studies based on NGS data. For GWAS, small effects dictated large sample sizes, typically made possible through meta-analysis by exchanging summary statistics across consortia. NGS studies groupwise-test for association of multiple potentially-causal alleles along each gene. They are subject to similar power constraints and therefore likely to resort to meta-analysis as well. The problem arises when considering privacy of the genetic information during the data-exchange process. Many scoring schemes for NGS association rely on the frequency of each variant thus requiring the exchange of identity of the sequenced variant. As such variants are often rare, potentially revealing the identity of their carriers and jeopardizing privacy. We have thus developed MetaSeq, a protocol for meta-analysis of genome-wide sequencing data by multiple collaborating parties, scoring association for rare variants pooled per gene across all parties. We tackle the challenge of tallying frequency counts of rare, sequenced alleles, for metaanalysis of sequencing data without disclosing the allele identity and counts, thereby protecting sample identity. This apparent paradoxical exchange of information is achieved through cryptographic means. The key idea is that parties encrypt identity of genes and variants. When they transfer information about frequency counts in cases and controls, the exchanged data does not convey the identity of a mutation and therefore does not expose carrier identity. The exchange relies on a 3rd party, trusted to follow the protocol although not trusted to learn about the raw data. We show applicability of this method to publicly available exome-sequencing data from multiple studies, simulating phenotypic information for powerful meta-analysis. The MetaSeq software is publicly available as open source.

Traumatic stress and accelerated DNA methylation age: A meta-analysis.

Science.gov (United States)

Wolf, Erika J; Maniates, Hannah; Nugent, Nicole; Maihofer, Adam X; Armstrong, Don; Ratanatharathorn, Andrew; Ashley-Koch, Allison E; Garrett, Melanie; Kimbrel, Nathan A; Lori, Adriana; Va Mid-Atlantic Mirecc Workgroup; Aiello, Allison E; Baker, Dewleen G; Beckham, Jean C; Boks, Marco P; Galea, Sandro; Geuze, Elbert; Hauser, Michael A; Kessler, Ronald C; Koenen, Karestan C; Miller, Mark W; Ressler, Kerry J; Risbrough, Victoria; Rutten, Bart P F; Stein, Murray B; Ursano, Robert J; Vermetten, Eric; Vinkers, Christiaan H; Uddin, Monica; Smith, Alicia K; Nievergelt, Caroline M; Logue, Mark W

2018-06-01

Recent studies examining the association between posttraumatic stress disorder (PTSD) and accelerated aging, as defined by DNA methylation-based estimates of cellular age that exceed chronological age, have yielded mixed results. We conducted a meta-analysis of trauma exposure and PTSD diagnosis and symptom severity in association with accelerated DNA methylation age using data from 9 cohorts contributing to the Psychiatric Genomics Consortium PTSD Epigenetics Workgroup (combined N = 2186). Associations between demographic and cellular variables and accelerated DNA methylation age were also examined, as was the moderating influence of demographic variables. Meta-analysis of regression coefficients from contributing cohorts revealed that childhood trauma exposure (when measured with the Childhood Trauma Questionnaire) and lifetime PTSD severity evidenced significant, albeit small, meta-analytic associations with accelerated DNA methylation age (ps = 0.028 and 0.016, respectively). Sex, CD4T cell proportions, and natural killer cell proportions were also significantly associated with accelerated DNA methylation age (all ps age. There was no evidence of moderation of the trauma or PTSD variables by demographic factors. Results suggest that traumatic stress is associated with advanced epigenetic age and raise the possibility that cells integral to immune system maintenance and responsivity play a role in this. This study highlights the need for additional research into the biological mechanisms linking traumatic stress to accelerated DNA methylation age and the importance of furthering our understanding of the neurobiological and health consequences of PTSD. Published by Elsevier Ltd.

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.

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.

Student Satisfaction in Higher Education: A Meta-Analytic Study

Science.gov (United States)

Santini, Fernando de Oliveira; Ladeira, Wagner Junior; Sampaio, Claudio Hoffmann; da Silva Costa, Gustavo

2017-01-01

This paper discusses the results of a meta-analysis performed to identify key antecedent and consequent constructs of satisfaction in higher education. We offer an integrated model to achieve a better understanding of satisfaction in the context of higher education. To accomplish this objective, we identified 83 studies that were valid and…

Hypothermia after cardiac arrest should be further evaluated-A systematic review of randomised trials with meta-analysis and trial sequential analysis

DEFF Research Database (Denmark)

Nielsen, Niklas; Friberg, Hans; Gluud, Christian

2011-01-01

BACKGROUND: Guidelines recommend mild induced hypothermia (MIH) to reduce mortality and neurological impairment after out-of-hospital cardiac arrest. Our objective was to systematically evaluate the evidence for MIH taking into consideration the risks of systematic and random error and to GRADE...... the evidence. METHODS: Systematic review with meta-analysis and trial sequential analysis of randomised trials evaluating MIH after cardiac arrest in adults. We searched CENTRAL, MEDLINE, and EMBASE databases until May 2009. Retrieved trials were evaluated with Cochrane methodology. Meta-analytic estimates....... The substantial risk of bias and concerns with directness rated down the quality of the evidence to low. CONCLUSIONS: Evidence regarding MIH after out-of-hospital cardiac arrest is still inconclusive and associated with non-negligible risks of systematic and random errors. Using GRADE-methodology, we conclude...

Education and Entrepreneurship in Industrialized Countries: A Meta-analysis

NARCIS (Netherlands)

vander Sluis, J.; van Praag, C.M.; Vijverberg, W.

2004-01-01

This paper provides a meta-analytical review of empirical studies into the impact of schooling on entrepreneurship selection and performance. We first describe the main effects found in the current entrepreneurship literature. We then explain the variance in results across the hundreds of empirical

Cognitive Evaluation Theory: A Meta-Analytic Review of the Literature.

Science.gov (United States)

Rummel, Amy; Feinberg, Richard

1988-01-01

Employed meta-analysis to determine existence of the detrimental effects of extrinsic rewards on intrinsic motivation. Results showed that within strictly defined parameters the phenomenon concerning the detrimental effects of reward described in Deci's Cognitive Evaluation Theory did exist. (Author/NB)

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.

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....

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.

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

Science.gov (United States)

Cheung, Shu Fai; Chan, Darius K-S

2014-06-01

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

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

A Meta-Analysis of Acculturation/Enculturation and Mental Health

Science.gov (United States)

Yoon, Eunju; Chang, Chih-Ting; Kim, Soyeon; Clawson, Angela; Cleary, Sarah Elizabeth; Hansen, Meghan; Bruner, John P.; Chan, Theresa K.; Gomes, Alexandrina M.

2013-01-01

This meta-analytic study examined the relationship among the constructs of acculturation, enculturation, and acculturation strategies (i.e., integration, assimilation, separation, marginalization), and mental health. Data from 325 studies (163 journal articles and 162 dissertation studies) were analyzed using a random-effects model, across a broad…

Predicting organic food consumption: A meta-analytic structural equation model based on the theory of planned behavior.

Science.gov (United States)

Scalco, Andrea; Noventa, Stefano; Sartori, Riccardo; Ceschi, Andrea

2017-05-01

During the last decade, the purchase of organic food within a sustainable consumption context has gained momentum. Consequently, the amount of research in the field has increased, leading in some cases to discrepancies regarding both methods and results. The present review examines those works that applied the theory of planned behavior (TPB; Ajzen, 1991) as a theoretical framework in order to understand and predict consumers' motivation to buy organic food. A meta-analysis has been conducted to assess the strength of the relationships between attitude, subjective norms, perceived behavioral control, and intention, as well as between intention and behavior. Results confirm the major role played by individual attitude in shaping buying intention, followed by subjective norms and perceived behavioral control. Intention-behavior shows a large effect size, few studies however explicitly reported such an association. Furthermore, starting from a pooled correlation matrix, a meta-analytic structural equation model has been applied to jointly evaluate the strength of the relationships among the factors of the original model. Results suggest the robustness of the TPB model. In addition, mediation analysis indicates a potential direct effect from subjective norms to individual attitude in the present context. Finally, some issues regarding methodological aspects of the application of the TPB within the context of organic food are discussed for further research developments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effectiveness of Intelligent Tutoring Systems: A Meta-Analytic Review

Science.gov (United States)

Kulik, James A.; Fletcher, J. D.

2016-01-01

This review describes a meta-analysis of findings from 50 controlled evaluations of intelligent computer tutoring systems. The median effect of intelligent tutoring in the 50 evaluations was to raise test scores 0.66 standard deviations over conventional levels, or from the 50th to the 75th percentile. However, the amount of improvement found in…

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.

Bleeding and pneumonia in intensive care patients given ranitidine and sucralfate for prevention of stress ulcer: meta-analysis of randomised controlled trials

Science.gov (United States)

Messori, A; Trippoli, S; Vaiani, M; Gorini, M; Corrado, A

2000-01-01

Objectives To determine the effectiveness of ranitidine and sucralfate in the prevention of stress ulcer in critical patients and to assess if these treatments affect the risk of nosocomial pneumonia. Design Published studies retrieved through Medline and other databases. Five meta-analyses evaluated effectiveness in terms of bleeding rates (A: ranitidine v placebo; B: sucralfate v placebo) and infectious complications in terms of incidence of nosocomial pneumonia (C: ranitidine v placebo; D: sucralfate v placebo; E: ranitidine v sucralfate). Trial quality was determined with an empirical ad hoc procedure. Main outcome measures Rates of clinically important gastrointestinal bleeding and nosocomial pneumonia (compared between the two study arms and expressed with odds ratios specific for individual studies and meta-analytic summary odds ratios). Results Meta-analysis A (five studies) comprised 398 patients; meta-analysis C (three studies) comprised 311 patients; meta-analysis D (two studies) comprised 226 patients: and meta-analysis E (eight studies) comprised 1825 patients. Meta-analysis B was not carried out as the literature search selected only one clinical trial. In meta-analysis A ranitidine was found to have the same effectiveness as placebo (odds ratio of bleeding 0.72, 95% confidence interval 0.30 to 1.70, P=0.46). In placebo controlled studies (meta-analyses C and D) ranitidine and sucralfate had no influence on the incidence of nosocomial pneumonia. In comparison with sucralfate, ranitidine significantly increased the incidence of nosocomial pneumonia (meta-analysis E: 1.35, 1.07 to 1.70, P=0.012). The mean quality score in the four analyses (on a 0 to 10 scale) ranged from 5.6 in meta-analysis E to 6.6 in meta-analysis A. Conclusions Ranitidine is ineffective in the prevention of gastrointestinal bleeding in patients in intensive care and might increase the risk of pneumonia. Studies on sucralfate do not provide conclusive results. These findings are

Heavy metal phytoremediation from a meta-analytical perspective

Energy Technology Data Exchange (ETDEWEB)

Audet, Patrick [Ottawa-Carleton Institute of Biology, Department of Biology, University of Ottawa, 30 Marie-Curie St., Ottawa, Ont. K1N 6N5 (Canada)]. E-mail: paude086@uottawa.ca; Charest, Christiane [Ottawa-Carleton Institute of Biology, Department of Biology, University of Ottawa, 30 Marie-Curie St., Ottawa, Ont. K1N 6N5 (Canada)]. E-mail: ccharest@science.uottawa.ca

2007-05-15

We conducted a literature survey and correlated heavy metal (HM) uptake and plant growth factors from published data to estimate the effectiveness of phytoextraction. The indicators of the actual plant HM uptake showed positive correlations with soil-HM concentrations, while the relative plant HM uptake showed negative correlations. Plant growth was negatively correlated with both the plant and soil-HM concentrations. These significant relationships were found for the majority of HM tested (e.g. Zn, Cd, Pb, Cu, Cr, and Fe) with a few exceptions (e.g. Ni, Co, and Mn). After fitting the correlation coefficients, the highest proportion of variance among the studies was mainly due to the experimental parameters or the plant species. When the metabolic costs of HM uptake are taken into account, the phytoextraction appears to be less effective beyond critical HM concentrations. Despite these constraints, it is emphasized that HM phytoextraction can play an important role in bioremediation. - This meta-analytical approach has revealed a compromise between growth and HM uptake when plants are subjected to toxic soil-HM levels.

Heavy metal phytoremediation from a meta-analytical perspective

International Nuclear Information System (INIS)

Audet, Patrick; Charest, Christiane

2007-01-01

We conducted a literature survey and correlated heavy metal (HM) uptake and plant growth factors from published data to estimate the effectiveness of phytoextraction. The indicators of the actual plant HM uptake showed positive correlations with soil-HM concentrations, while the relative plant HM uptake showed negative correlations. Plant growth was negatively correlated with both the plant and soil-HM concentrations. These significant relationships were found for the majority of HM tested (e.g. Zn, Cd, Pb, Cu, Cr, and Fe) with a few exceptions (e.g. Ni, Co, and Mn). After fitting the correlation coefficients, the highest proportion of variance among the studies was mainly due to the experimental parameters or the plant species. When the metabolic costs of HM uptake are taken into account, the phytoextraction appears to be less effective beyond critical HM concentrations. Despite these constraints, it is emphasized that HM phytoextraction can play an important role in bioremediation. - This meta-analytical approach has revealed a compromise between growth and HM uptake when plants are subjected to toxic soil-HM levels

Do people with chronic pain have impaired executive function? A meta-analytical review.

Science.gov (United States)

Berryman, Carolyn; Stanton, Tasha R; Bowering, K Jane; Tabor, Abby; McFarlane, Alexander; Moseley, G Lorimer

2014-11-01

A widely held belief within the clinical community is that chronic pain is associated with cognitive impairment, despite the absence of a definitive systematic review or meta-analysis on the topic. The current systematic review and meta-analysis aimed to establish the current evidence concerning the difference in executive function between people with chronic pain and healthy controls. Six databases were searched for citations related to executive function and chronic pain from inception to June 24, 2013. Two reviewers independently assessed studies for eligibility and extracted relevant data according to the Cochrane Collaboration and Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Twenty five studies were included in the review and twenty two studies in the meta-analysis. A small to moderate impairment in executive function performance was found in people with chronic pain across cognitive components, although all studies had a high risk of bias. The current evidence suggests impairment of executive function in people with chronic pain, however, important caveats exist. First, executive function involves many cognitive components and there is no standard test for it. Second, moderators of executive function, such as medication and sleep, were seldom controlled for in studies of executive function performance. Copyright © 2014 Elsevier Ltd. All rights reserved.

Mega-Analysis of School Psychology Blueprint for Training and Practice Domains

Science.gov (United States)

Burns, Matthew K.; Kanive, Rebecca; Zaslofsky, Anne F.; Parker, David C.

2013-01-01

Meta-analytic research is an effective method for synthesizing existing research and for informing practice and policy. Hattie (2009) suggested that meta-analytic procedures could be employed to existing meta-analyses to create a mega-analysis. The current mega-analysis examined a sample of 47 meta-analyses according to the "School…

A Thematic-Based Meta Analytic Study Regarding the Effect of Creativity on Academic Success and Learning Retention

Science.gov (United States)

Özdas, Faysal; Batdi, Veli

2017-01-01

This thematic-based meta-analytic study aims to examine the effect of creativity on the academic success and learning retention scores of students. In the context of this aim, 18 out of 225 studies regarding creativity that were carried out between 2001 and 2011 have been obtained from certain national and international databases. The studies…

Social network analysis using k-Path centrality method

Science.gov (United States)

Taniarza, Natya; Adiwijaya; Maharani, Warih

2018-03-01

k-Path centrality is deemed as one of the effective methods to be applied in centrality measurement in which the influential node is estimated as the node that is being passed by information path frequently. Regarding this, k-Path centrality has been employed in the analysis of this paper specifically by adapting random-algorithm approach in order to: (1) determine the influential user’s ranking in a social media Twitter; and (2) ascertain the influence of parameter α in the numeration of k-Path centrality. According to the analysis, the findings showed that the method of k-Path centrality with random-algorithm approach can be used to determine user’s ranking which influences in the dissemination of information in Twitter. Furthermore, the findings also showed that parameter α influenced the duration and the ranking results: the less the α value, the longer the duration, yet the ranking results were more stable.

Positive psychology interventions: A meta-analysis of randomized controlled studies

NARCIS (Netherlands)

Bolier, Linda; Haverman, M.; Westerhof, Gerben Johan; Riper, H.; Smit, F.; Bohlmeijer, Ernst Thomas

2013-01-01

Background The use of positive psychological interventions may be considered as a complementary strategy in mental health promotion and treatment. The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for

Positive psychology interventions: a meta-analysis of randomized controlled studies

NARCIS (Netherlands)

Bolier, L.; Haverman, M.; Westerhof, G.J.; Riper, H.; Smit, H.F.E.; Bohlmeijer, E.

2013-01-01

Background: The use of positive psychological interventions may be considered as a complementary strategy in mental health promotion and treatment. The present article constitutes a meta-analytical study of the effectiveness of positive psychology interventions for the general public and for

Neural Correlates of Psychotherapy in Anxiety and Depression: A Meta-Analysis

Science.gov (United States)

Messina, Irene; Sambin, Marco; Palmieri, Arianna; Viviani, Roberto

2013-01-01

Several studies have used neuroimaging methods to identify neural change in brain networks associated to emotion regulation after psychotherapy of depression and anxiety. In the present work we adopted a meta-analytic technique specific to neuroimaging data to evaluate the consistence of empirical findings and assess models of therapy that have been proposed in the literature. Meta-analyses were conducted with the Activation Likelihood Estimation technique, which evaluates the overlap between foci of activation across studies. The analysis included 16 studies found in Pubmed (200 foci of activation and 193 patients). Separate meta-analyses were conducted on studies of 1) depression, post-traumatic stress disorder and panic disorder investigated with rest state metabolism (6 studies, 70 patients); 2) depression, post-traumatic stress disorder and panic disorder investigated with task-related activation studies (5 studies, 65 patients); 3) the previous studies considered jointly; and 4) phobias investigated with studies on exposure-related activation (5 studies, 57 patients). Studies on anxiety and depression gave partially consistent results for changes in the dorsomedial prefrontal cortex and in the posterior cingulated gyrus/precuneus. Several areas of change in the temporal lobes were also observed. Studies on the therapy of phobia were consistent with a reduction of activity in medial temporal areas. The cluster of change in the prefrontal cortex may refer to increased recruitment of control processes, as hypothesized by influential models of emotion regulation changes due to psychotherapy. However, not all areas associated with controlled emotion regulation were detected in the meta-analysis, while involvement of midline structures suggested changes in self-related information processing. Changes in phobia were consistent with reduced reactivity to phobic stimuli. PMID:24040309

Neural correlates of psychotherapy in anxiety and depression: a meta-analysis.

Directory of Open Access Journals (Sweden)

Irene Messina

Full Text Available Several studies have used neuroimaging methods to identify neural change in brain networks associated to emotion regulation after psychotherapy of depression and anxiety. In the present work we adopted a meta-analytic technique specific to neuroimaging data to evaluate the consistence of empirical findings and assess models of therapy that have been proposed in the literature. Meta-analyses were conducted with the Activation Likelihood Estimation technique, which evaluates the overlap between foci of activation across studies. The analysis included 16 studies found in Pubmed (200 foci of activation and 193 patients. Separate meta-analyses were conducted on studies of 1 depression, post-traumatic stress disorder and panic disorder investigated with rest state metabolism (6 studies, 70 patients; 2 depression, post-traumatic stress disorder and panic disorder investigated with task-related activation studies (5 studies, 65 patients; 3 the previous studies considered jointly; and 4 phobias investigated with studies on exposure-related activation (5 studies, 57 patients. Studies on anxiety and depression gave partially consistent results for changes in the dorsomedial prefrontal cortex and in the posterior cingulated gyrus/precuneus. Several areas of change in the temporal lobes were also observed. Studies on the therapy of phobia were consistent with a reduction of activity in medial temporal areas. The cluster of change in the prefrontal cortex may refer to increased recruitment of control processes, as hypothesized by influential models of emotion regulation changes due to psychotherapy. However, not all areas associated with controlled emotion regulation were detected in the meta-analysis, while involvement of midline structures suggested changes in self-related information processing. Changes in phobia were consistent with reduced reactivity to phobic stimuli.

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

Effects of Botanical Insecticides on Hymenopteran Parasitoids: a Meta-analysis Approach.

Science.gov (United States)

Monsreal-Ceballos, R J; Ruiz-Sánchez, E; Ballina-Gómez, H S; Reyes-Ramírez, A; González-Moreno, A

2018-02-10

Botanical insecticides (BIs) are considered a valuable alternative for plant protection in sustainable agriculture. The use of both BIs and parasitoids are presumed to be mutually compatible pest management practices. However, there is controversy on this subject, as various studies have reported lethal and sublethal effects of BIs on hymenopteran parasitoids. To shed new light on this controversy, a meta-analytic approach of the effects of BIs on adult mortality, parasitism, and parasitoid emergence under laboratory conditions was performed. We show that BIs increased mortality, decreased parasitism, and decreased parasitoid emergence. Botanical insecticides derived from Nicotiana tabacum and Caceolaria andina were particulary lethal. Most of the parasitoid groups showed susceptibility to BIs, but the families Scelionidae and Ichneumonidae were not significantly affected. The negative effects of BIs were seen regardless of the type of exposure (topical, ingestion, or residual). In conclusion, this meta-analysis showed that under laboratory conditions, exposure of hymenopteran parasitoids to BIs had significant negative effects on adult mortality, parasitism, and parasitoid emergence.

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.

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.

Metallothionein - immunohistochemical cancer biomarker: a meta-analysis.

Directory of Open Access Journals (Sweden)

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

Diversion Path Analysis Handbook. Volume 1. Methodology

International Nuclear Information System (INIS)

Goodwin, K.E.; Schleter, J.C.; Maltese, M.D.K.

1978-11-01

Diversion Path Analysis (DPA) is a safeguards evaluation tool which is used to determine the vulnerability of the Material Control and Material Accounting (MC and MA) Subsystems to the threat of theft of Special Nuclear Material (SNM) by a knowledgeable Insider. The DPA team should consist of two individuals who have technical backgrounds. The implementation of DPA is divided into five basic steps: Information and Data Gathering, Process Characterization, Analysis of Diversion Paths, Results and Findings, and Documentation

A meta-analytic review of the relationship between family accommodation and OCD symptom severity.

Science.gov (United States)

Strauss, Clara; Hale, Lucy; Stobie, Blake

2015-06-01

Accommodation of obsessive compulsive disorder (OCD) symptoms by family members is common. This paper presents a systematic meta-analytic review on family accommodation and OCD symptom severity. Fourteen studies investigating the relationship between family accommodation and OCD symptoms were selected. The medium effect size of the relationship between family accommodation and OCD symptom severity was significant (r = .35; 95% CI: .23 to .47), based on a Hunter-Schmidt random effects model with a total of 849 participants. Although there was some evidence of publication bias, Rosenthal's fail-safe N suggested that 596 studies with zero effect would be needed to reduce the mean effect size to non-significant. Findings are discussed in the context of the limitations of the studies, and in particular the reliance on cross-sectional designs which impede causal conclusions. Future research to evaluate a family accommodation intervention in a randomized controlled design and using mediation analysis to explore change mechanisms is called for. Copyright © 2015 Elsevier Ltd. All rights reserved.

Conducting Meta-Analyses Based on p Values

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

2016-01-01

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

A Bayesian network meta-analysis for binary outcome: how to do it.

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Greco, Teresa; Landoni, Giovanni; Biondi-Zoccai, Giuseppe; D'Ascenzo, Fabrizio; Zangrillo, Alberto

2016-10-01

This study presents an overview of conceptual and practical issues of a network meta-analysis (NMA), particularly focusing on its application to randomised controlled trials with a binary outcome of interest. We start from general considerations on NMA to specifically appraise how to collect study data, structure the analytical network and specify the requirements for different models and parameter interpretations, with the ultimate goal of providing physicians and clinician-investigators a practical tool to understand pros and cons of NMA. Specifically, we outline the key steps, from the literature search to sensitivity analysis, necessary to perform a valid NMA of binomial data, exploiting Markov Chain Monte Carlo approaches. We also apply this analytical approach to a case study on the beneficial effects of volatile agents compared to total intravenous anaesthetics for surgery to further clarify the statistical details of the models, diagnostics and computations. Finally, datasets and models for the freeware WinBUGS package are presented for the anaesthetic agent example. © The Author(s) 2013.

Food and drug cues activate similar brain regions: a meta-analysis of functional MRI studies.

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Tang, D W; Fellows, L K; Small, D M; Dagher, A

2012-06-06

In healthy individuals, food cues can trigger hunger and feeding behavior. Likewise, smoking cues can trigger craving and relapse in smokers. Brain imaging studies report that structures involved in appetitive behaviors and reward, notably the insula, striatum, amygdala and orbital frontal cortex, tend to be activated by both visual food and smoking cues. Here, by carrying out a meta-analysis of human neuro-imaging studies, we investigate the neural network activated by: 1) food versus neutral cues (14 studies, 142 foci) 2) smoking versus neutral cues (15 studies, 176 foci) 3) smoking versus neutral cues when correlated with craving scores (7 studies, 108 foci). PubMed was used to identify cue-reactivity imaging studies that compared brain response to visual food or smoking cues to neutral cues. Fourteen articles were identified for the food meta-analysis and fifteen articles were identified for the smoking meta-analysis. Six articles were identified for the smoking cue correlated with craving analysis. Meta-analyses were carried out using activation likelihood estimation. Food cues were associated with increased blood oxygen level dependent (BOLD) response in the left amygdala, bilateral insula, bilateral orbital frontal cortex, and striatum. Smoking cues were associated with increased BOLD signal in the same areas, with the exception of the insula. However, the smoking meta-analysis of brain maps correlating cue-reactivity with subjective craving did identify the insula, suggesting that insula activation is only found when craving levels are high. The brain areas identified here are involved in learning, memory and motivation, and their cue-induced activity is an index of the incentive salience of the cues. Using meta-analytic techniques to combine a series of studies, we found that food and smoking cues activate comparable brain networks. There is significant overlap in brain regions responding to conditioned cues associated with natural and drug rewards

A Meta-analysis on Resting State High-frequency Heart Rate Variability in Bulimia Nervosa.

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Peschel, Stephanie K V; Feeling, Nicole R; Vögele, Claus; Kaess, Michael; Thayer, Julian F; Koenig, Julian

2016-09-01

Autonomic nervous system function is altered in eating disorders. We aimed to quantify differences in resting state vagal activity, indexed by high-frequency heart rate variability comparing patients with bulimia nervosa (BN) and healthy controls. A systematic search of the literature to identify studies eligible for inclusion and meta-analytical methods were applied. Meta-regression was used to identify potential covariates. Eight studies reporting measures of resting high-frequency heart rate variability in individuals with BN (n = 137) and controls (n = 190) were included. Random-effects meta-analysis revealed a sizeable main effect (Z = 2.22, p = .03; Hedge's g = 0.52, 95% CI [0.06;0.98]) indicating higher resting state vagal activity in individuals with BN. Meta-regression showed that body mass index and medication intake are significant covariates. Findings suggest higher vagal activity in BN at rest, particularly in unmedicated samples with lower body mass index. Potential mechanisms underlying these findings and implications for routine clinical care are discussed. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

Recognition of Emotions in Autism: A Formal Meta-Analysis

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Uljarevic, Mirko; Hamilton, Antonia

2013-01-01

Determining the integrity of emotion recognition in autistic spectrum disorder is important to our theoretical understanding of autism and to teaching social skills. Previous studies have reported both positive and negative results. Here, we take a formal meta-analytic approach, bringing together data from 48 papers testing over 980 participants…

The Relationship between Spirituality and Religiosity on Psychological Outcomes in Adolescents and Emerging Adults: A Meta-Analytic Review

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Yonker, Julie E.; Schnabelrauch, Chelsea A.; DeHaan, Laura G.

2012-01-01

The present study used meta-analytic techniques to examine the association between spirituality and religiosity (S/R) and psychological outcomes in adolescents and emerging adults. The outcome measures of risk behavior, depression, well-being, self-esteem, and personality were examined with respect to the influence of S/R across 75 independent…

Multivariate meta-analysis: Potential and promise

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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

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

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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 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.

The Happy Culture: A Theoretical, Meta-Analytic, and Empirical Review of the Relationship Between Culture and Wealth and Subjective Well-Being

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Steel, Piers; Taras, Vasyl; Uggerslev, Krista; Bosco, Frank

2017-01-01

Do cultural values enhance financial and subjective well-being (SWB)? Taking a multidisciplinary approach, we meta-analytically reviewed the field, found it thinly covered, and focused on individualism. In counter, we collected a broad array of individual-level data, specifically an Internet sample of 8,438 adult respondents. Individual SWB was most strongly associated with cultural values that foster relationships and social capital, which typically accounted for more unique variance in life satisfaction than an individual’s salary. At a national level, we used mean-based meta-analysis to construct a comprehensive cultural and SWB database. Results show some reversals from the individual level, particularly masculinity’s facet of achievement orientation. In all, the happy nation has low power distance and low uncertainty avoidance, but is high in femininity and individualism, and these effects are interrelated but still partially independent from political and economic institutions. In short, culture matters for individual and national well-being. PMID:28770649

The Happy Culture: A Theoretical, Meta-Analytic, and Empirical Review of the Relationship Between Culture and Wealth and Subjective Well-Being.

Science.gov (United States)

Steel, Piers; Taras, Vasyl; Uggerslev, Krista; Bosco, Frank

2018-05-01

Do cultural values enhance financial and subjective well-being (SWB)? Taking a multidisciplinary approach, we meta-analytically reviewed the field, found it thinly covered, and focused on individualism. In counter, we collected a broad array of individual-level data, specifically an Internet sample of 8,438 adult respondents. Individual SWB was most strongly associated with cultural values that foster relationships and social capital, which typically accounted for more unique variance in life satisfaction than an individual's salary. At a national level, we used mean-based meta-analysis to construct a comprehensive cultural and SWB database. Results show some reversals from the individual level, particularly masculinity's facet of achievement orientation. In all, the happy nation has low power distance and low uncertainty avoidance, but is high in femininity and individualism, and these effects are interrelated but still partially independent from political and economic institutions. In short, culture matters for individual and national well-being.

Dynamic Path Analysis in Life-Course Epidemiology

DEFF Research Database (Denmark)

Gamborg, Michael Orland; Boje Jensen, Gorm; Sørensen, Thorkild I.A.

2011-01-01

it works through other risk factors. In this paper, the dynamic path analysis model is presented as a tool to analyze these dynamic mechanisms in life-course epidemiology. A key feature of dynamic path analysis is its ability to decompose the total effect of a risk factor into a direct effect (not mediated...... by other variables) and indirect effects (mediated through other variables). This is illustrated by examining the associations between repeated measurements of body mass index (BMI) and systolic blood pressure (SBP) and the risk of CHD in a sample of Danish men between 1976 and 2006. The effect of baseline...... BMI on the risk of CHD is decomposed into a direct effect and indirect effects going through later BMI, concurrent SBP, or later SBP. In conclusion, dynamic path analysis is a flexible tool that by the decomposition of effects can be used to increase the understanding of mechanisms that underlie...

Effect of Glycemic Index of Breakfast on Energy Intake at Subsequent Meal among Healthy People: A Meta-Analysis

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Feng-Hua Sun

2016-01-01

Full Text Available Meals with low glycemic index (GI may suppress short-term appetite and reduce subsequent food intake compared with high-GI meals. However, no meta-analysis has been conducted to synthesize the evidence. This meta-analytic study was conducted to assess the effect of high- and low-GI breakfast on subsequent short-term food intake. Trials were identified through MEDLINE, EMBASE, Web of Science, and Cochrane Central Register of Controlled trials, and manual searches of bibliographies until May 2015. Randomized controlled and cross-over trials comparing the effect of low- with high-GI breakfast on subsequent energy intake among healthy people were included. Nine studies consisting of 11 trials met the inclusion criteria. Only one trial was classified with high methodological quality. A total of 183 participants were involved in the trials. The meta-analytic results revealed no difference in breakfast GI (high-GI vs. low-GI on subsequent short-term energy intake. In conclusion, it seems that breakfast GI has no effect on short-term energy intake among healthy people. However, high quality studies are still warranted to provide more concrete evidence.

A meta-analytic review of the effects of exercise on brain-derived neurotrophic factor

OpenAIRE

Szuhany, Kristin L.; Bugatti, Matteo; Otto, Michael W.

2014-01-01

Consistent evidence indicates that exercise improves cognition and mood, with preliminary evidence suggesting that brain-derived neurotrophic factor (BDNF) may mediate these effects. The aim of the current meta-analysis was to provide an estimate of the strength of the association between exercise and increased BDNF levels in humans across multiple exercise paradigms. We conducted a meta-analysis of 29 studies (N = 1,111 participants) examining the effect of exercise on BDNF levels in three e...

The revelation effect: A meta-analytic test of hypotheses.

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Aßfalg, André; Bernstein, Daniel M; Hockley, William

2017-12-01

Judgments can depend on the activity directly preceding them. An example is the revelation effect whereby participants are more likely to claim that a stimulus is familiar after a preceding task, such as solving an anagram, than without a preceding task. We test conflicting predictions of four revelation-effect hypotheses in a meta-analysis of 26 years of revelation-effect research. The hypotheses' predictions refer to three subject areas: (1) the basis of judgments that are subject to the revelation effect (recollection vs. familiarity vs. fluency), (2) the degree of similarity between the task and test item, and (3) the difficulty of the preceding task. We use a hierarchical multivariate meta-analysis to account for dependent effect sizes and variance in experimental procedures. We test the revelation-effect hypotheses with a model selection procedure, where each model corresponds to a prediction of a revelation-effect hypothesis. We further quantify the amount of evidence for one model compared to another with Bayes factors. The results of this analysis suggest that none of the extant revelation-effect hypotheses can fully account for the data. The general vagueness of revelation-effect hypotheses and the scarcity of data were the major limiting factors in our analyses, emphasizing the need for formalized theories and further research into the puzzling revelation effect.

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

A meta-analysis of the relationship between general mental ability and nontask performance.

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Gonzalez-Mulé, Erik; Mount, Michael K; Oh, In-Sue

2014-11-01

Although one of the most well-established research findings in industrial-organizational psychology is that general mental ability (GMA) is a strong and generalizable predictor of job performance, this meta-analytically derived conclusion is based largely on measures of task or overall performance. The primary purpose of this study is to address a void in the research literature by conducting a meta-analysis to determine the direction and magnitude of the correlation of GMA with 2 dimensions of nontask performance: counterproductive work behaviors (CWB) and organizational citizenship behaviors (OCB). Overall, the results show that the true-score correlation between GMA and CWB is essentially 0 (-.02, k = 35), although rating source of CWB moderates this relationship. The true-score correlation between GMA and OCB is positive but modest in magnitude (.23, k = 43). The 2nd purpose of this study is to conduct meta-analytic relative weight analyses to determine the relative importance of GMA and the five-factor model (FFM) of personality traits in predicting nontask and task performance criteria. Results indicate that, collectively, the FFM traits are substantially more important for CWB than GMA, that the FFM traits are roughly equal in importance to GMA for OCB, and that GMA is substantially more important for task and overall job performance than the FFM traits. Implications of these findings for the development of optimal selection systems and the development of comprehensive theories of job performance are discussed along with study limitation and future research directions. (PsycINFO Database Record (c) 2014 APA, all rights reserved).

A Meta-Analysis of Interventions to Reduce Adolescent Cannabis Use

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Bender, Kimberly; Tripodi, Stephen J.; Sarteschi, Christy; Vaughn, Michael G.

2011-01-01

Objective: This meta-analytic review assesses the effectiveness of substance abuse interventions to reduce adolescent cannabis use. Method: A systematic search identified 15 randomized controlled evaluations of interventions to reduce adolescent cannabis use published between 1960 and 2008. The primary outcome variables, frequency of cannabis use,…

Effect of exercise interventions on perceived fatigue in people with multiple sclerosis: synthesis of meta-analytic reviews.

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Safari, Reza; Van der Linden, Marietta L; Mercer, Tom H

2017-06-01

Although exercise training has been advocated as a nonpharmacological treatment for multiple sclerosis (MS) related fatigue, no consensus exists regarding its effectiveness. To address this, we collated meta-analytic reviews that explored the effectiveness of exercise training for the treatment of MS-related fatigue. We searched five online databases for relevant reviews, published since 2005, and identified 172 records. Five reviews were retained for systematic extraction of information and evidence quality analysis. Although our review synthesis indicated that exercise training interventions have a moderate effect on fatigue reduction in people with MS, no clear insight was obtained regarding the relative effectiveness of specific types or modes of exercise intervention. Moreover, Grading of Recommendation Assessment, Development and Evaluation revealed that the overall quality of evidence emanating from these five reviews was 'very low'.

Path space measures for Dirac and Schroedinger equations: Nonstandard analytical approach

International Nuclear Information System (INIS)

Nakamura, T.

1997-01-01

A nonstandard path space *-measure is constructed to justify the path integral formula for the Dirac equation in two-dimensional space endash time. A standard measure as well as a standard path integral is obtained from it. We also show that, even for the Schroedinger equation, for which there is no standard measure appropriate for a path integral, there exists a nonstandard measure to define a *-path integral whose standard part agrees with the ordinary path integral as defined by a limit from time-slice approximant. copyright 1997 American Institute of Physics

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

Directory of Open Access Journals (Sweden)

Mark J Bolland

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

Psychosocial Factors and Community College Student Success: A Meta-Analytic Investigation

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Fong, Carlton J.; Davis, Coreen W.; Kim, Yughi; Kim, Young Won; Marriott, Lauren; Kim, SooYeon

2017-01-01

This meta-analysis examined the relationship between psychosocial factors and community college student success. Informed by college persistence models and motivational theory, we statistically integrated past research on five psychosocial categories (motivation, self-perceptions, attributions, self-regulation, and anxiety), examining their…

A methodological systematic review of what's wrong with meta-ethnography reporting.

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France, Emma F; Ring, Nicola; Thomas, Rebecca; Noyes, Jane; Maxwell, Margaret; Jepson, Ruth

2014-11-19

Syntheses of qualitative studies can inform health policy, services and our understanding of patient experience. Meta-ethnography is a systematic seven-phase interpretive qualitative synthesis approach well-suited to producing new theories and conceptual models. However, there are concerns about the quality of meta-ethnography reporting, particularly the analysis and synthesis processes. Our aim was to investigate the application and reporting of methods in recent meta-ethnography journal papers, focusing on the analysis and synthesis process and output. Methodological systematic review of health-related meta-ethnography journal papers published from 2012-2013. We searched six electronic databases, Google Scholar and Zetoc for papers using key terms including 'meta-ethnography.' Two authors independently screened papers by title and abstract with 100% agreement. We identified 32 relevant papers. Three authors independently extracted data and all authors analysed the application and reporting of methods using content analysis. Meta-ethnography was applied in diverse ways, sometimes inappropriately. In 13% of papers the approach did not suit the research aim. In 66% of papers reviewers did not follow the principles of meta-ethnography. The analytical and synthesis processes were poorly reported overall. In only 31% of papers reviewers clearly described how they analysed conceptual data from primary studies (phase 5, 'translation' of studies) and in only one paper (3%) reviewers explicitly described how they conducted the analytic synthesis process (phase 6). In 38% of papers we could not ascertain if reviewers had achieved any new interpretation of primary studies. In over 30% of papers seminal methodological texts which could have informed methods were not cited. We believe this is the first in-depth methodological systematic review of meta-ethnography conduct and reporting. Meta-ethnography is an evolving approach. Current reporting of methods, analysis and

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.

The effect of dietary restriction on reproduction: a meta-analytic perspective.

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Moatt, Joshua P; Nakagawa, Shinichi; Lagisz, Malgorzata; Walling, Craig A

2016-10-07

Dietary restriction (DR), a reduction in the amount of food or particular nutrients eaten, is the most consistent environmental manipulation to extend lifespan and protect against age related diseases. Current evolutionary theory explains this effect as a shift in the resolution of the trade-off between lifespan and reproduction. However, recent studies have questioned the role of reproduction in mediating the effect of DR on longevity and no study has quantitatively investigated the effect of DR on reproduction across species. Here we report a comprehensive comparative meta-analysis of the effect of DR on reproduction. In general, DR reduced reproduction across taxa, but several factors moderated this effect. The effect of DR on reproduction was greater in well-studied model species (yeast, nematode worms, fruit flies and rodents) than non-model species. This mirrors recent results for longevity and, for reproduction, seems to result from a faster rate of decline with decreasing resources in model species. Our results also suggested that not all reproductive traits are affected equally by DR. High and moderate cost reproductive traits suffered a significant reduction with DR, but low cost traits, such as ejaculate production, did not. Although the effect of DR on reproduction was stronger in females than males, this sex difference reduced to near zero when accounting for other co-factors such as the costliness of the reproductive trait. Thus, sex differences in the effect of DR on longevity may be due to a failure to expose males to as complete a range of the costs of reproduction as females. We suggest that to better understand the generality of the effect of DR, future studies should attempt to address the cause of the apparent model species bias and ensure that individuals are exposed to as many of the costs of reproduction as possible. Furthermore, our meta-analytic approach reveals a general shortage of DR studies that record reproduction, particularly in

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...

Path probabilities of continuous time random walks

International Nuclear Information System (INIS)

Eule, Stephan; Friedrich, Rudolf

2014-01-01

Employing the path integral formulation of a broad class of anomalous diffusion processes, we derive the exact relations for the path probability densities of these processes. In particular, we obtain a closed analytical solution for the path probability distribution of a Continuous Time Random Walk (CTRW) process. This solution is given in terms of its waiting time distribution and short time propagator of the corresponding random walk as a solution of a Dyson equation. Applying our analytical solution we derive generalized Feynman–Kac formulae. (paper)

Meta-Analysis of Psychological Assessment as a Therapeutic Intervention

Science.gov (United States)

Poston, John M.; Hanson, William E.

2010-01-01

This study entails the use of meta-analytic techniques to calculate and analyze 18 independent and 52 nonindependent effect sizes across 17 published studies of psychological assessment as a therapeutic intervention. In this sample of studies, which involves 1,496 participants, a significant overall Cohen's d effect size of 0.423 (95% CI [0.321,…

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

Age differences in the effect of framing on risky choice: A meta-analysis

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Best, Ryan; Charness, Neil

2015-01-01

The framing of decision scenarios in terms of potential gains versus losses has been shown to influence choice preferences between sure and risky options. Normative cognitive changes associated with aging have been known to affect decision-making, which has led to a number of studies investigating the influence of aging on the effect of framing. Mata, Josef, Samanez-Larkin, and Hertwig (2011) systematically reviewed the available literature using a meta-analytic approach, but did not include tests of homogeneity nor subsequent moderator variable analyses. The current review serves to extend the previous analysis to include such tests as well as update the pool of studies available for analysis. Results for both positively and negatively framed conditions were reviewed using two meta-analyses encompassing data collected from 3,232 subjects across 18 studies. Deviating from the previous results, the current analysis finds a tendency for younger adults to choose the risky option more often than older adults for positively framed items. Moderator variable analyses find this effect to likely be driven by the specific decision scenario, showing a significant effect with younger adults choosing the risky option more often in small-amount financial and large-amount mortality-based scenarios. For negatively framed items, the current review found no overall age difference in risky decision making, confirming the results from the prior meta-analysis. Moderator variable analyses conducted to address heterogeneity found younger adults to be more likely than older adults to choose the risky option for negatively framed high-amount mortality-based decision scenarios. Practical implications for older adults are discussed. PMID:26098168

Spanking, corporal punishment and negative long-term outcomes: a meta-analytic review of longitudinal studies.

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Ferguson, Christopher J

2013-02-01

Social scientists continue to debate the impact of spanking and corporal punishment (CP) on negative child outcomes including externalizing and internalizing behavior problems and cognitive performance. Previous meta-analytic reviews have mixed long- and short-term studies and relied on bivariate r, which may inflate effect sizes. The current meta-analysis focused on longitudinal studies, and compared effects using bivariate r and better controlled partial r coefficients controlling for time-1 outcome variables. Consistent with previous findings, results based on bivariate r found small but non-trivial long-term relationships between spanking/CP use and negative outcomes. Spanking and CP correlated .14 and .18 respectively with externalizing problems, .12 and .21 with internalizing problems and -.09 and -.18 with cognitive performance. However, when better controlled partial r coefficients (pr) were examined, results were statistically significant but trivial (at or below pr = .10) for externalizing (.07 for spanking, .08 for CP) and internalizing behaviors (.10 for spanking, insufficient studies for CP) and near the threshold of trivial for cognitive performance (-.11 for CP, insufficient studies for spanking). It is concluded that the impact of spanking and CP on the negative outcomes evaluated here (externalizing, internalizing behaviors and low cognitive performance) are minimal. It is advised that psychologists take a more nuanced approach in discussing the effects of spanking/CP with the general public, consistent with the size as well as the significance of their longitudinal associations with adverse outcomes.

Empirical Comparison of Publication Bias Tests in Meta-Analysis.

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

2018-04-16

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

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.

A meta-analytic review of moral licensing.

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Blanken, Irene; van de Ven, Niels; Zeelenberg, Marcel

2015-04-01

Moral licensing refers to the effect that when people initially behave in a moral way, they are later more likely to display behaviors that are immoral, unethical, or otherwise problematic. We provide a state-of-the-art overview of moral licensing by conducting a meta-analysis of 91 studies (7,397 participants) that compare a licensing condition with a control condition. Based on this analysis, the magnitude of the moral licensing effect is estimated to be a Cohen's d of 0.31. We tested potential moderators and found that published studies tend to have larger moral licensing effects than unpublished studies. We found no empirical evidence for other moderators that were theorized to be of importance. The effect size estimate implies that studies require many more participants to draw solid conclusions about moral licensing and its possible moderators. © 2015 by the Society for Personality and Social Psychology, Inc.

Computing the optimal path in stochastic dynamical systems

International Nuclear Information System (INIS)

Bauver, Martha; Forgoston, Eric; Billings, Lora

2016-01-01

In stochastic systems, one is often interested in finding the optimal path that maximizes the probability of escape from a metastable state or of switching between metastable states. Even for simple systems, it may be impossible to find an analytic form of the optimal path, and in high-dimensional systems, this is almost always the case. In this article, we formulate a constructive methodology that is used to compute the optimal path numerically. The method utilizes finite-time Lyapunov exponents, statistical selection criteria, and a Newton-based iterative minimizing scheme. The method is applied to four examples. The first example is a two-dimensional system that describes a single population with internal noise. This model has an analytical solution for the optimal path. The numerical solution found using our computational method agrees well with the analytical result. The second example is a more complicated four-dimensional system where our numerical method must be used to find the optimal path. The third example, although a seemingly simple two-dimensional system, demonstrates the success of our method in finding the optimal path where other numerical methods are known to fail. In the fourth example, the optimal path lies in six-dimensional space and demonstrates the power of our method in computing paths in higher-dimensional spaces.

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.

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

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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.

Caregiver's education level and child's dental caries in African Americans: A path analytic study

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Heima, Masahiro; Lee, Wonik; Milgrom, Peter; Nelson, Suchitra

2015-01-01

The objective of this study was to investigate the influence of caregiver education level on children's dental caries mediated by both caregiver and child oral health behaviors. Participants were 423 low-income African American kindergarteners and their caregivers who were part of a school-based randomized clinical trial. Path analysis tested the hypothesis that caregiver education level affected untreated dental caries and cumulative overall caries experience (decayed or filled teeth) through the mediating influence of frequency of dental visits, use of routine care, and frequency of toothbrushing for both caregiver and child. The results supported the hypothesis: Caregivers who completed high school were 1.76 times more likely to visit dentists themselves compared with those who did not complete high school (e0.56=1.76, 95%CI: 1.03-2.99), which in turn was associated with 5.78 times greater odds of dental visits among their children (e1.76=5.78, 95%CI: 3.53-9.48). Children's dental visits, subsequently, were associated with 26% fewer untreated decayed teeth compared with children without dental visits (e-0.31=0.74, 95%CI: 0.60-0.91). However, this path was not present in the model with overall caries experience. Additionally, caregiver education level was directly associated with 34% less untreated decayed teeth (e-0.42=0.66, 95% CI: 0.54-0.79) and 28% less decayed or filled teeth (e-0.32=0.72, 95%CI: 0.60-0.88) among the children. This study overcomes important conceptual and analytic limitations in the existing literature. The findings confirm the role of caregiver education in child dental caries and indicate that caregiver's behavioral factors are important mediators of child oral health. PMID:25661111

Inhibition deficits in individuals with intellectual disability: a meta-regression analysis

NARCIS (Netherlands)

Bexkens, A.; Ruzzano, L.; Collot D'Escury-Koenigs, A.M.L.; van der Molen, M.W.; Huizenga, H.M.

2014-01-01

Background: Individuals with intellectual disabilities (ID) are characterised by inhibition deficits; however, the magnitude of these deficits is still subject to debate. This meta-analytic study therefore has two aims: first to assess the magnitude of inhibition deficits in ID, and second to

Rational Emotive Therapy with Children and Adolescents: A Meta-Analysis

Science.gov (United States)

Gonzalez, Jorge E.; Nelson, J. Ron; Gutkin, Terry B.; Saunders, Anita; Galloway, Ann; Shwery, Craig S.

2004-01-01

This article systematically reviews the available research on rational emotive behavioral therapy (REBT) with children and adolescents. Meta-analytic procedures were applied to 19 studies that met inclusion criteria. The overall mean weighted effect of REBT was positive and significant. Weighted z[r] effect sizes were also computed for five…

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

Posttraumatic growth following acquired brain injury: A systematic review and meta-analysis

Directory of Open Access Journals (Sweden)

Elaine Louise Kinsella

2015-08-01

Full Text Available The idea that acquired brain injury (ABI caused by stroke, haemorrhage, infection or traumatic insult to the brain can result in posttraumatic growth (PTG for individuals is increasingly attracting psychological attention. However PTG also attracts controversy as a result of ambiguous empirical findings. The extent that demographic variables, injury factors, subjective beliefs, and psychological health are associated with PTG following ABI is not clear. Consequently, this systematic review and meta-analysis explores the correlates of variables within these four broad areas and PTG. From a total of 744 published studies addressing PTG in people with ABI, eight studies met inclusion criteria for detailed examination. Meta-analysis of these studies indicated that growth was related to employment, longer education, subjective beliefs about change post-injury, relationship status, older age, longer time since injury, and lower levels of depression. Results from homogeneity analyses indicated significant inter-study heterogeneity across variables. There is general support for the idea that people with ABI can experience growth, and that various demographics, injury-related variables, subjective beliefs and psychological health are related to growth. The contribution of social integration and the forming of new identities post-ABI to the experience of PTG is explored. These meta-analytic findings are however constrained by methodological limitations prevalent in the literature. Clinical and research implications are discussed with specific reference to community and collective factors that enable PTG.

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

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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.

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...

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.

Diagnostic Stability of ICD/DSM First Episode Psychosis Diagnoses: Meta-analysis

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Fusar-Poli, Paolo; Cappucciati, Marco; Rutigliano, Grazia; Heslin, Margaret; Stahl, Daniel; Brittenden, Zera; Caverzasi, Edgardo; McGuire, Philip; Carpenter, William T.

2016-01-01

Background: Validity of current International Classification of Disease/Diagnostic and Statistical Manual of Mental Disorders (ICD/DSM) first episode psychosis diagnoses is essential in clinical practice, research, training and public health. Method: We provide a meta-analytical estimate of prospective diagnostic stability and instability in ICD-10 or DSM-IV first episode diagnoses of functional psychoses. Independent extraction by multiple observers. Random effect meta-analysis conducted with the “metaprop,” “metaninf,” “metafunnel,” “metabias,” and “metareg” packages of STATA13.1. Moderators were tested with meta-regression analyses. Heterogeneity was assessed with the I 2 index. Sensitivity analyses tested robustness of results. Publication biases were assessed with funnel plots and Egger’s test. Findings: 42 studies and 45 samples were included, for a total of 14 484 first episode patients and an average follow-up of 4.5 years. Prospective diagnostic stability ranked: schizophrenia 0.90 (95% CI 0.85–0.95), affective spectrum psychoses 0.84 (95% CI 0.79–0.89), schizoaffective disorder 0.72 (95% CI 0.61–0.73), substance-induced psychotic disorder 0.66 (95% CI 0.51–0.81), delusional disorder 0.59 (95% CI 0.47–0.71), acute and transient psychotic disorder/brief psychotic disorder 0.56 (95% CI 0.62–0.60), psychosis not otherwise specified 0.36 (95% CI 0.27–0.45, schizophreniform disorder 0.29 (95% CI 0.22–0.38). Diagnostic stability within schizophrenia spectrum psychoses was 0.93 (95% CI 0.89–0.97); changes to affective spectrum psychoses were 0.05 (95% CI 0.01–0.08). About 0.10 (95% CI 0.05–0.15) of affective spectrum psychoses changed to schizophrenia spectrum psychosis. Across the other psychotic diagnoses there was high diagnostic instability, mostly to schizophrenia. Interpretation: There is meta-analytical evidence for high prospective diagnostic stability in schizophrenia spectrum and affective spectrum psychoses

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...

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:…

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.

Interventions to reduce sexual prejudice: a study-space analysis and meta-analytic review.

Science.gov (United States)

Bartoş, Sebastian E; Berger, Israel; Hegarty, Peter

2014-01-01

Sexual prejudice is an important threat to the physical and mental well-being of lesbians, gay men, and bisexual people. Therefore, we reviewed the effectiveness of interventions designed to reduce such prejudice. A study-space analysis was performed on published and unpublished papers from all over the world to identify well-studied and underexplored issues. Most studies were conducted with North American undergraduates and were educational in nature. Dissertations were often innovative and well designed but were rarely published. We then performed meta-analyses on sets of comparable studies. Education, contact with gay people, and combining contact with education had a medium-size effect on several measures of sexual prejudice. The manipulation of social norms was effective in reducing antigay behavior. Other promising interventions, such as the use of entertainment media to promote tolerance, need further investigation. More research is also needed on populations other than American students, particularly groups who may have higher levels of sexual prejudice.

Workflows in bioinformatics: meta-analysis and prototype implementation of a workflow generator

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Thoraval Samuel

2005-04-01

Full Text Available Abstract Background Computational methods for problem solving need to interleave information access and algorithm execution in a problem-specific workflow. The structures of these workflows are defined by a scaffold of syntactic, semantic and algebraic objects capable of representing them. Despite the proliferation of GUIs (Graphic User Interfaces in bioinformatics, only some of them provide workflow capabilities; surprisingly, no meta-analysis of workflow operators and components in bioinformatics has been reported. Results We present a set of syntactic components and algebraic operators capable of representing analytical workflows in bioinformatics. Iteration, recursion, the use of conditional statements, and management of suspend/resume tasks have traditionally been implemented on an ad hoc basis and hard-coded; by having these operators properly defined it is possible to use and parameterize them as generic re-usable components. To illustrate how these operations can be orchestrated, we present GPIPE, a prototype graphic pipeline generator for PISE that allows the definition of a pipeline, parameterization of its component methods, and storage of metadata in XML formats. This implementation goes beyond the macro capacities currently in PISE. As the entire analysis protocol is defined in XML, a complete bioinformatic experiment (linked sets of methods, parameters and results can be reproduced or shared among users. Availability: http://if-web1.imb.uq.edu.au/Pise/5.a/gpipe.html (interactive, ftp://ftp.pasteur.fr/pub/GenSoft/unix/misc/Pise/ (download. Conclusion From our meta-analysis we have identified syntactic structures and algebraic operators common to many workflows in bioinformatics. The workflow components and algebraic operators can be assimilated into re-usable software components. GPIPE, a prototype implementation of this framework, provides a GUI builder to facilitate the generation of workflows and integration of heterogeneous

Molecular sub-classification of renal epithelial tumors using meta-analysis of gene expression microarrays.

Directory of Open Access Journals (Sweden)

Thomas Sanford

Full Text Available To evaluate the accuracy of the sub-classification of renal cortical neoplasms using molecular signatures.A search of publicly available databases was performed to identify microarray datasets with multiple histologic sub-types of renal cortical neoplasms. Meta-analytic techniques were utilized to identify differentially expressed genes for each histologic subtype. The lists of genes obtained from the meta-analysis were used to create predictive signatures through the use of a pair-based method. These signatures were organized into an algorithm to sub-classify renal neoplasms. The use of these signatures according to our algorithm was validated on several independent datasets.We identified three Gene Expression Omnibus datasets that fit our criteria to develop a training set. All of the datasets in our study utilized the Affymetrix platform. The final training dataset included 149 samples represented by the four most common histologic subtypes of renal cortical neoplasms: 69 clear cell, 41 papillary, 16 chromophobe, and 23 oncocytomas. When validation of our signatures was performed on external datasets, we were able to correctly classify 68 of the 72 samples (94%. The correct classification by subtype was 19/20 (95% for clear cell, 14/14 (100% for papillary, 17/19 (89% for chromophobe, 18/19 (95% for oncocytomas.Through the use of meta-analytic techniques, we were able to create an algorithm that sub-classified renal neoplasms on a molecular level with 94% accuracy across multiple independent datasets. This algorithm may aid in selecting molecular therapies and may improve the accuracy of subtyping of renal cortical tumors.

Testing a path-analytic mediation model of how motivational enhancement physiotherapy improves physical functioning in pain patients.

Science.gov (United States)

Cheing, Gladys; Vong, Sinfia; Chan, Fong; Ditchman, Nicole; Brooks, Jessica; Chan, Chetwyn

2014-12-01

Pain is a complex phenomenon not easily discerned from psychological, social, and environmental characteristics and is an oft cited barrier to return to work for people experiencing low back pain (LBP). The purpose of this study was to evaluate a path-analytic mediation model to examine how motivational enhancement physiotherapy, which incorporates tenets of motivational interviewing, improves physical functioning of patients with chronic LBP. Seventy-six patients with chronic LBP were recruited from the outpatient physiotherapy department of a government hospital in Hong Kong. The re-specified path-analytic model fit the data very well, χ (2)(3, N = 76) = 3.86, p = .57; comparative fit index = 1.00; and the root mean square error of approximation = 0.00. Specifically, results indicated that (a) using motivational interviewing techniques in physiotherapy was associated with increased working alliance with patients, (b) working alliance increased patients' outcome expectancy and (c) greater outcome expectancy resulted in a reduction of subjective pain intensity and improvement in physical functioning. Change in pain intensity also directly influenced improvement in physical functioning. The effect of motivational enhancement therapy on physical functioning can be explained by social-cognitive factors such as motivation, outcome expectancy, and working alliance. The use of motivational interviewing techniques to increase outcome expectancy of patients and improve working alliance could further strengthen the impact of physiotherapy on rehabilitation outcomes of patients with chronic LBP.

Screening Performance Characteristic of Ultrasonography and Radiography in Detection of Pleural Effusion; a Meta-Analysis.

Science.gov (United States)

Yousefifard, Mahmoud; Baikpour, Masoud; Ghelichkhani, Parisa; Asady, Hadi; Shahsavari Nia, Kavous; Moghadas Jafari, Ali; Hosseini, Mostafa; Safari, Saeed

2016-01-01

The role of ultrasonography in detection of pleural effusion has long been a subject of interest but controversial results have been reported. Accordingly, this study aims to conduct a systematic review of the available literature on diagnostic value of ultrasonography and radiography in detection of pleural effusion through a meta-analytic approach. An extended search was done in databases of Medline, EMBASE, ISI Web of Knowledge, Scopus, Cochrane Library, and ProQuest. Two reviewers independently extracted the data and assessed the quality of the articles. Meta-analysis was performed using a mixed-effects binary regression model. Finally, subgroup analysis was carried out in order to find the sources of heterogeneity between the included studies. 12 studies were included in this meta-analysis (1554 subjects, 58.6% male). Pooled sensitivity of ultrasonography in detection of pleural effusion was 0.94 (95% CI: 0.88-0.97; I2= 84.23, pultrasonography was found to be higher when the procedure was carried out by an intensivist or a radiologist using 5-10 MHz transducers. Chest ultrasonography, as a screening tool, has a higher diagnostic accuracy in identification of plural effusion compared to radiography. The sensitivity of this imaging modality was found to be higher when performed by a radiologist or an intensivist and using 5-10MHz probes.

Memory training interventions for older adults: a meta-analysis.

Science.gov (United States)

Gross, Alden L; Parisi, Jeanine M; Spira, Adam P; Kueider, Alexandra M; Ko, Jean Y; Saczynski, Jane S; Samus, Quincy M; Rebok, George W

2012-01-01

A systematic review and meta-analysis of memory training research was conducted to characterize the effect of memory strategies on memory performance among cognitively intact, community-dwelling older adults, and to identify characteristics of individuals and of programs associated with improved memory. The review identified 402 publications, of which 35 studies met criteria for inclusion. The overall effect size estimate, representing the mean standardized difference in pre-post change between memory-trained and control groups, was 0.31 standard deviations (SD; 95% confidence interval (CI): 0.22, 0.39). The pre-post training effect for memory-trained interventions was 0.43 SD (95% CI: 0.29, 0.57) and the practice effect for control groups was 0.06 SD (95% CI: 0.05, 0.16). Among 10 distinct memory strategies identified in studies, meta-analytic methods revealed that training multiple strategies was associated with larger training gains (p=0.04), although this association did not reach statistical significance after adjusting for multiple comparisons. Treatment gains among memory-trained individuals were not better after training in any particular strategy, or by the average age of participants, session length, or type of control condition. These findings can inform the design of future memory training programs for older adults.

Abreaction for conversion disorder: systematic review with meta-analysis.

Science.gov (United States)

Poole, Norman A; Wuerz, Axel; Agrawal, Niruj

2010-08-01

The value of drug interviews in the treatment of conversion disorder is at present unknown. To review all the available papers published in English that report on the use of drug interviews for treating conversion/dissociative disorder. Databases (including EMBASE, MEDLINE and PsycINFO) were searched from 1920 to 2009. Selected publications had to report on the use of drug interviews in people diagnosed with a conversion/dissociative disorder. Qualitative and quantitative data were extracted. Predictors of a positive response were ascertained using meta-analytic techniques. Fifty-five papers meeting inclusion criteria were identified. No studies compared the intervention with a suitable control group. However, two studies reported high response rates when drug interview was used in individuals with treatment-resistant conversion disorder. In the meta-analysis, the use of suggestion and occurrence of emotional catharsis during the interview were positively associated with recovery. Combining two medications and comorbid psychiatric disorder were negatively associated with recovery. The evidence for effectiveness of drug interviews is of poor quality but it may be of benefit in the treatment of acute and treatment-resistant conversion disorder. A proactive approach during the interview, making suggestions the individual will respond, could influence outcome. Comorbid psychiatric disorder should be treated conventionally. Experimental studies to determine efficacy are required.

A meta-analysis of executive components of working memory.

Science.gov (United States)

Nee, Derek Evan; Brown, Joshua W; Askren, Mary K; Berman, Marc G; Demiralp, Emre; Krawitz, Adam; Jonides, John

2013-02-01

Working memory (WM) enables the online maintenance and manipulation of information and is central to intelligent cognitive functioning. Much research has investigated executive processes of WM in order to understand the operations that make WM "work." However, there is yet little consensus regarding how executive processes of WM are organized. Here, we used quantitative meta-analysis to summarize data from 36 experiments that examined executive processes of WM. Experiments were categorized into 4 component functions central to WM: protecting WM from external distraction (distractor resistance), preventing irrelevant memories from intruding into WM (intrusion resistance), shifting attention within WM (shifting), and updating the contents of WM (updating). Data were also sorted by content (verbal, spatial, object). Meta-analytic results suggested that rather than dissociating into distinct functions, 2 separate frontal regions were recruited across diverse executive demands. One region was located dorsally in the caudal superior frontal sulcus and was especially sensitive to spatial content. The other was located laterally in the midlateral prefrontal cortex and showed sensitivity to nonspatial content. We propose that dorsal-"where"/ventral-"what" frameworks that have been applied to WM maintenance also apply to executive processes of WM. Hence, WM can largely be simplified to a dual selection model.

The effect of loving-kindness meditation on positive emotions: a meta-analytic review.

Science.gov (United States)

Zeng, Xianglong; Chiu, Cleo P K; Wang, Rong; Oei, Tian P S; Leung, Freedom Y K

2015-01-01

While it has been suggested that loving-kindness meditation (LKM) is an effective practice for promoting positive emotions, the empirical evidence in the literature remains unclear. Here, we provide a systematic review of 24 empirical studies (N = 1759) on LKM with self-reported positive emotions. The effect of LKM on positive emotions was estimated with meta-analysis, and the influence of variations across LKM interventions was further explored with subgroup analysis and meta-regression. The meta-analysis showed that (1) medium effect sizes for LKM interventions on daily positive emotions in both wait-list controlled RCTs and non-RCT studies; and (2) small to large effect sizes for the on-going practice of LKM on immediate positive emotions across different comparisons. Further analysis showed that (1) interventions focused on loving-kindness had medium effect size, but interventions focused on compassion showed small effect sizes; (2) the length of interventions and the time spent on meditation did not influence the effect sizes, but the studies without didactic components in interventions had small effect sizes. A few individual studies reported that the nature of positive emotions and individual differences also influenced the results. In sum, LKM practice and interventions are effective in enhancing positive emotions, but more studies are needed to identify the active components of the interventions, to compare different psychological operations, and to explore the applicability in clinical populations.

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...

Ethical leadership: meta-analytic evidence of criterion-related and incremental validity.

Science.gov (United States)

Ng, Thomas W H; Feldman, Daniel C

2015-05-01

This study examines the criterion-related and incremental validity of ethical leadership (EL) with meta-analytic data. Across 101 samples published over the last 15 years (N = 29,620), we observed that EL demonstrated acceptable criterion-related validity with variables that tap followers' job attitudes, job performance, and evaluations of their leaders. Further, followers' trust in the leader mediated the relationships of EL with job attitudes and performance. In terms of incremental validity, we found that EL significantly, albeit weakly in some cases, predicted task performance, citizenship behavior, and counterproductive work behavior-even after controlling for the effects of such variables as transformational leadership, use of contingent rewards, management by exception, interactional fairness, and destructive leadership. The article concludes with a discussion of ways to strengthen the incremental validity of EL. (PsycINFO Database Record (c) 2015 APA, all rights reserved).

In Sync and in Control: A Meta-Analysis of Parent-Child Positive Behavioral Synchrony and Youth Self-Regulation.

Science.gov (United States)

Davis, Molly; Bilms, Joanie; Suveg, Cynthia

2017-12-01

A growing body of research has highlighted the connection between parent-child positive behavioral synchrony and youth self-regulation; however, this association has yet to be the focus of a meta-analytic review. Therefore, the present meta-analysis aimed to estimate the magnitude of the relation between parent-child positive behavioral synchrony and youth self-regulation and to identify moderator variables that can explain the variability in the degree of this association across the extant literature. A thorough literature search of two major databases, in addition to scanning the reference sections of relevant articles, yielded a total of 10 peer-reviewed articles (24 effect sizes, 658 children) that were eligible for inclusion in the current meta-analysis. Results from the overall mean effect size calculation using a random-effects model indicated that parent-child positive behavioral synchrony was significantly, positively correlated with youth self-regulation and the effect size was medium. Children's ages at the time of synchrony and self-regulation measurements, as well as parent gender, served as significant moderator variables. Findings from the present meta-analysis can help to refine existing theoretical models on the role of the parent-child relationship in youth adjustment. Prevention and intervention efforts may benefit from an increased emphasis on building parent-child positive behavioral synchrony to promote youth self-regulation and thus children's overall well-being. © 2016 Family Process Institute.

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...

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.

A meta-analysis of the price elasticity of gasoline demand. A SUR approach

Energy Technology Data Exchange (ETDEWEB)

Brons, Martijn; Rietveld, Piet [Department of Spatial Economics, Vrije Universiteit, De Boelelaan 1105, 1081 HV Amsterdam (Netherlands); Tinbergen Institute Amsterdam (TIA), Roetersstraat 31, 1018 WB Amsterdam (Netherlands); Nijkamp, Peter [Department of Spatial Economics, Vrije Universiteit, De Boelelaan 1105, 1081 HV Amsterdam (Netherlands); Tinbergen Institute Amsterdam (TIA), Roetersstraat 31, 1018 WB Amsterdam (Netherlands); The Netherlands Organisation of Scientific Research (NWO), postbus 93138 - 2509 AC Den Haag (Netherlands); Pels, Eric [Department of Spatial Economics, Vrije Universiteit, De Boelelaan 1105, 1081 HV Amsterdam (Netherlands)

2008-09-15

Automobile gasoline demand can be expressed as a multiplicative function of fuel efficiency, mileage per car and car ownership. This implies a linear relationship between the price elasticity of total fuel demand and the price elasticities of fuel efficiency, mileage per car and car ownership. In this meta-analytical study we aim to investigate and explain the variation in empirical estimates of the price elasticity of gasoline demand. A methodological novelty is that we use the linear relationship between the elasticities to develop a meta-analytical estimation approach based on a Seemingly Unrelated Regression (SUR) model with Cross Equation Restrictions. This approach enables us to combine observations of different elasticities and thus increase our sample size. Furthermore, it allows for a more detailed interpretation of our meta-regression results. The empirical results of the study demonstrate that the SUR approach leads to more precise results (i.e., lower standard errors) than a standard meta-analytical approach. We find that, with mean short run and long run price elasticities of - 0.34 and - 0.84, respectively, the demand for gasoline is not very price sensitive. Both in the short and the long run, the impact of a change in the gasoline price on demand is mainly driven by responses in fuel efficiency and mileage per car and to a slightly lesser degree by changes in car ownership. Furthermore, we find that study characteristics relating to the geographic area studied, the year of the study, the type of data used, the time horizon and the functional specification of the demand equation have a significant impact on the estimated value of the price elasticity of gasoline demand. (author)

A meta-analysis of the price elasticity of gasoline demand. A SUR approach

International Nuclear Information System (INIS)

Brons, Martijn; Rietveld, Piet; Nijkamp, Peter; Pels, Eric

2008-01-01

Automobile gasoline demand can be expressed as a multiplicative function of fuel efficiency, mileage per car and car ownership. This implies a linear relationship between the price elasticity of total fuel demand and the price elasticities of fuel efficiency, mileage per car and car ownership. In this meta-analytical study we aim to investigate and explain the variation in empirical estimates of the price elasticity of gasoline demand. A methodological novelty is that we use the linear relationship between the elasticities to develop a meta-analytical estimation approach based on a Seemingly Unrelated Regression (SUR) model with Cross Equation Restrictions. This approach enables us to combine observations of different elasticities and thus increase our sample size. Furthermore, it allows for a more detailed interpretation of our meta-regression results. The empirical results of the study demonstrate that the SUR approach leads to more precise results (i.e., lower standard errors) than a standard meta-analytical approach. We find that, with mean short run and long run price elasticities of - 0.34 and - 0.84, respectively, the demand for gasoline is not very price sensitive. Both in the short and the long run, the impact of a change in the gasoline price on demand is mainly driven by responses in fuel efficiency and mileage per car and to a slightly lesser degree by changes in car ownership. Furthermore, we find that study characteristics relating to the geographic area studied, the year of the study, the type of data used, the time horizon and the functional specification of the demand equation have a significant impact on the estimated value of the price elasticity of gasoline demand. (author)

Planning performance in schizophrenia patients: a meta-analysis of the influence of task difficulty and clinical and sociodemographic variables.

Science.gov (United States)

Knapp, F; Viechtbauer, W; Leonhart, R; Nitschke, K; Kaller, C P

2017-08-01

Despite a large body of research on planning performance in adult schizophrenia patients, results of individual studies are equivocal, suggesting either no, moderate or severe planning deficits. This meta-analysis therefore aimed to quantify planning deficits in schizophrenia and to examine potential sources of the heterogeneity seen in the literature. The meta-analysis comprised outcomes of planning accuracy of 1377 schizophrenia patients and 1477 healthy controls from 31 different studies which assessed planning performance using tower tasks such as the Tower of London, the Tower of Hanoi and the Stockings of Cambridge. A meta-regression analysis was applied to assess the influence of potential moderator variables (i.e. sociodemographic and clinical variables as well as task difficulty). The findings indeed demonstrated a planning deficit in schizophrenia patients (mean effect size: ; 95% confidence interval 0.56-0.78) that was moderated by task difficulty in terms of the minimum number of moves required for a solution. The results did not reveal any significant relationship between the extent of planning deficits and sociodemographic or clinical variables. The current results provide first meta-analytic evidence for the commonly assumed impairments of planning performance in schizophrenia. Deficits are more likely to become manifest in problem items with higher demands on planning ahead, which may at least partly explain the heterogeneity of previous findings. As only a small fraction of studies reported coherent information on sample characteristics, future meta-analyses would benefit from more systematic reports on those variables.

A meta-analysis of hypnosis for chronic pain problems: a comparison between hypnosis, standard care, and other psychological interventions.

Science.gov (United States)

Adachi, Tomonori; Fujino, Haruo; Nakae, Aya; Mashimo, Takashi; Sasaki, Jun

2014-01-01

Hypnosis is regarded as an effective treatment for psychological and physical ailments. However, its efficacy as a strategy for managing chronic pain has not been assessed through meta-analytical methods. The objective of the current study was to conduct a meta-analysis to assess the efficacy of hypnosis for managing chronic pain. When compared with standard care, hypnosis provided moderate treatment benefit. Hypnosis also showed a moderate superior effect as compared to other psychological interventions for a nonheadache group. The results suggest that hypnosis is efficacious for managing chronic pain. Given that large heterogeneity among the included studies was identified, the nature of hypnosis treatment is further discussed.

A two-dimensional approach to relationship conflict: meta-analytic findings.

Science.gov (United States)

Woodin, Erica M

2011-06-01

This meta-analysis of 64 studies (5,071 couples) used a metacoding system to categorize observed couple conflict behaviors into categories differing in terms of valence (positive to negative) and intensity (high to low) and resulting in five behavioral categories: hostility, distress, withdrawal, problem solving, and intimacy. Aggregate effect sizes indicated that women were somewhat more likely to display hostility, distress, and intimacy during conflict, whereas men were somewhat more likely to display withdrawal and problem solving. Gender differences were of a small magnitude. For both men and women, hostility was robustly associated with lower relationship satisfaction (medium effect), distress and withdrawal were somewhat associated (small effect), and intimacy and problem solving were both closely associated with relationship satisfaction (medium effect). Effect sizes were moderated in several cases by study characteristics including year of publication, developmental period of the sample, recruitment design, duration of observed conflict, method used to induce conflict, and type of coding system used. Findings from this meta-analysis suggest that high-intensity conflict behaviors of both a positive and negative nature are important correlates of relationship satisfaction and underscore the relatively small gender differences in many conflict behaviors. 2011 APA, all rights reserved

Eye movement dysfunction in first-degree relatives of patients with schizophrenia: a meta-analytic evaluation of candidate endophenotypes.

Science.gov (United States)

Calkins, Monica E; Iacono, William G; Ones, Deniz S

2008-12-01

Several forms of eye movement dysfunction (EMD) are regarded as promising candidate endophenotypes of schizophrenia. Discrepancies in individual study results have led to inconsistent conclusions regarding particular aspects of EMD in relatives of schizophrenia patients. To quantitatively evaluate and compare the candidacy of smooth pursuit, saccade and fixation deficits in first-degree biological relatives, we conducted a set of meta-analytic investigations. Among 18 measures of EMD, memory-guided saccade accuracy and error rate, global smooth pursuit dysfunction, intrusive saccades during fixation, antisaccade error rate and smooth pursuit closed-loop gain emerged as best differentiating relatives from controls (standardized mean differences ranged from .46 to .66), with no significant differences among these measures. Anticipatory saccades, but no other smooth pursuit component measures were also increased in relatives. Visually-guided reflexive saccades were largely normal. Moderator analyses examining design characteristics revealed few variables affecting the magnitude of the meta-analytically observed effects. Moderate effect sizes of relatives v. controls in selective aspects of EMD supports their endophenotype potential. Future work should focus on facilitating endophenotype utility through attention to heterogeneity of EMD performance, relationships among forms of EMD, and application in molecular genetics studies.

Does oral language underpin the development of later behavior problems? A longitudinal meta-analysis.

Science.gov (United States)

Chow, Jason C; Ekholm, Erik; Coleman, Heather

2018-05-24

The purpose of this article is to estimate the overall weighted mean effect of the relation between early language skills and later behavior problems in school-aged children. A systematic literature search yielded 19,790 unduplicated reports, and a structured search strategy and identification procedure yielded 25 unique data sets, with 114 effect sizes for analysis. Eligible reports were then coded, and effect sizes were extracted and synthesized via robust variance estimation and random-effects meta-analytic techniques. The overall correlation between early language and later behavior problems was negative and small (r = -.14, 95% confidence interval [CI] [-.16, -.11]), and controlling for demographic variables did not reduce the magnitude of the inverse relationship between language skill and problem behavior (r = -.16). Moderator analyses identified receptive language, parent-reported behavior measures, gender, and age as significant predictors of the association between language and behavior. This article corroborates the consistent findings of previous meta-analytic and longitudinal studies and further identifies areas, particularly around measurement, for future research. Furthermore, prospective longitudinal evaluations of the relations between language deficits and behavior problems with different types of measures (teacher-/parent-report, direct assessment, classroom observation) is warranted. (PsycINFO Database Record (c) 2018 APA, 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.

Identifying null meta-analyses that are ripe for updating

Directory of Open Access Journals (Sweden)

Fang Manchun

2003-07-01

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

The Relation of Empathy and Defending in Bullying: A Meta-Analytic Investigation

Science.gov (United States)

Nickerson, Amanda B.; Aloe, Ariel M.; Werth, Jilynn M.

2015-01-01

This meta-analysis synthesized results about the association between empathy and defending in bullying. A total of 20 studies were included, with 22 effect sizes from 6 studies that separated findings by the defender's gender, and 31 effect sizes from 18 studies that provided effects for the total sample were included in the analysis. The weighted…

Does the Theory of Planned Behaviour Explain Condom Use Behaviour Among Men Who have Sex with Men? A Meta-analytic Review of the Literature.

Science.gov (United States)

Andrew, Benjamin J; Mullan, Barbara A; de Wit, John B F; Monds, Lauren A; Todd, Jemma; Kothe, Emily J

2016-12-01

The aim of this meta-analysis was to explore whether the constructs in the theory of planned behaviour (TPB; i.e., attitude, subjective norm, perceived behavioural control, intention) explain condom use behaviour among men who have sex with men (MSM). Electronic databases were searched for studies that measured TPB variables and MSM condom use. Correlations were meta-analysed using a random effects model and path analyses. Moderation analyses were conducted for the time frame of the behavioural measure used (retrospective versus prospective). Attitude, subjective norm and perceived behavioural control accounted for 24.0 % of the variance in condom use intention and were all significant correlates. Intention and PBC accounted for 12.4 % of the variance in condom use behaviour. However, after taking intention into account, PBC was no longer significantly associated with condom use. The strength of construct relationships did not differ between retrospective and prospective behavioural assessments. The medium to large effect sizes of the relationships between the constructs in the TPB, which are consistent with previous meta-analyses with different behaviours or target groups, suggest that the TPB is also a useful model for explaining condom use behaviour among MSM. However, the research in this area is rather small, and greater clarity over moderating factors can only be achieved when the literature expands.

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.

Age differences in the effect of framing on risky choice: A meta-analysis.

Science.gov (United States)

Best, Ryan; Charness, Neil

2015-09-01

The framing of decision scenarios in terms of potential gains versus losses has been shown to influence choice preferences between sure and risky options. Normative cognitive changes associated with aging have been known to affect decision making, which has led to a number of studies investigating the influence of aging on the effect of framing. Mata, Josef, Samanez-Larkin, and Hertwig (2011) systematically reviewed the available literature using a meta-analytic approach, but did not include tests of homogeneity or subsequent moderator variable analyses. The current review serves to extend the previous analysis to include such tests as well as update the pool of studies available for analysis. Results for both positively and negatively framed conditions were reviewed using 2 meta-analyses encompassing data collected from 3,232 subjects across 18 studies. Deviating from the previous results, the current analysis found a tendency for younger adults to choose the risky option more often than older adults for positively framed items. Moderator variable analyses found this effect likely to be driven by the specific decision scenario, showing a significant effect, with younger adults choosing the risky option more often in small-amount financial and large-amount mortality-based scenarios. For negatively framed items, the current review found no overall age difference in risky decision making, confirming the results from the prior meta-analysis. Moderator variable analyses conducted to address heterogeneity found younger adults to be more likely than older adults to choose the risky option for negatively framed high-amount mortality-based decision scenarios. Practical implications for older adults are discussed. (c) 2015 APA, all rights reserved).

Deflecting Rayleigh surface acoustic waves by a meta-ridge with a gradient phase shift

Science.gov (United States)

Xu, Yanlong; Yang, Zhichun; Cao, Liyun

2018-05-01

We propose a non-resonant meta-ridge to deflect Rayleigh surface acoustic waves (RSAWs) according to the generalized Snell’s law with a gradient phase shift. The gradient phase shift is predicted by an analytical formula, which is related to the path length of the traveling wave. The non-resonant meta-ridge is designed based on the characteristics of the RSAW: it only propagates along the interface with a penetration depth, and it is dispersion-free with a constant phase velocity. To guarantee that the characteristics are still valid when RSAWs propagate in a three-dimensional (3D) structure, grooves are employed to construct the supercell of the meta-ridge. The horizontal length, inclined angle, and thickness of the ridge, along with the filling ratio of the groove, are parametrically examined step by step to investigate their influences on the propagation of RSAWs. The final 3D meta-ridges are designed theoretically and their capability of deflecting the incident RSAWs are validated numerically. The study presents a new method to control the trajectory of RSAWs, which will be conducive to developing innovative devices for surface acoustic waves.

Are K-12 Learners Motivated in Physical Education? A Meta-Analysis

Science.gov (United States)

Chen, Senlin; Chen, Ang; Zhu, Xihe

2012-01-01

Previous studies devoted to K-12 learner motivation in physical education share a general assumption that students may lack motivation. This meta-analytic study examined published original studies (n = 79) to determine students' motivation level and the association between motivation and outcomes. Original means of motivation measures were…

Depression in HIV and HCV co-infected patients: a systematic review and meta-analysis.

Science.gov (United States)

Fialho, Renata; Pereira, Marco; Rusted, Jennifer; Whale, Richard

2017-10-01

The aim of this study was to carry out a systematic review and meta-analysis of the differences in the prevalence of depression and presence of depressive symptoms between HIV/HCV co-infection, HIV mono-infection, and hepatitis C virus (HCV) mono-infection. A systematic electronic search of bibliographic databases was performed to locate articles published from the earliest available online until December 2014. Outcomes of depression were based on clinical interviews and validated self-reported measures of depression/depressive symptoms. Of the 188 records initially screened, 29 articles were included in the descriptive systematic review and six were included in the meta-analysis. The meta-analytic results indicated that, as measured by self-reported measures of depression, HIV/HCV co-infected patients were significantly more likely to report depressive symptoms than either HIV (SMD = .24, 95% CI: .03-.46, p = .02) or HCV mono-infected (SMD = .55, 95% CI: .17-.94, p = .005) patients. The variability of the results of the reviewed studies, largely dependent on the samples' characteristics and the methods of assessment of depression, suggests that a clear interpretation of how depression outcomes are affected by the presence of HIV/HCV co-infection is still needed. Failing to diagnose depression or to early screen depressive symptoms may have a significant impact on patients' overall functioning and compromise treatments' outcomes.

Depressive realism: a meta-analytic review.

Science.gov (United States)

Moore, Michael T; Fresco, David M

2012-08-01

The current investigation represents the first meta-analysis of the depressive realism literature. A search of this literature revealed 75 relevant studies representing 7305 participants from across the US and Canada, as well as from England, Spain, and Israel. Results generally indicated a small overall depressive realism effect (Cohen's d=-.07). Overall, however, both dysphoric/depressed individuals (d=.14) and nondysphoric/nondepressed individuals evidenced a substantial positive bias (d=.29), with this bias being larger in nondysphoric/nondepressed individuals. Examination of potential moderator variables indicated that studies lacking an objective standard of reality (d=-.15 versus -.03, for studies possessing such a standard) and that utilize self-report measures to measure symptoms of depression (d=.16 versus -.04, for studies which utilize structured interviews) were more likely to find depressive realism effects. Methodological paradigm was also found to influence whether results consistent with depressive realism were found (d's ranged from -.09 to .14). Copyright © 2012 Elsevier Ltd. All rights reserved.

Neurocognition and symptoms identify links between facial recognition and emotion processing in schizophrenia: meta-analytic findings.

Science.gov (United States)

Ventura, Joseph; Wood, Rachel C; Jimenez, Amy M; Hellemann, Gerhard S

2013-12-01

In schizophrenia patients, one of the most commonly studied deficits of social cognition is emotion processing (EP), which has documented links to facial recognition (FR). But, how are deficits in facial recognition linked to emotion processing deficits? Can neurocognitive and symptom correlates of FR and EP help differentiate the unique contribution of FR to the domain of social cognition? A meta-analysis of 102 studies (combined n=4826) in schizophrenia patients was conducted to determine the magnitude and pattern of relationships between facial recognition, emotion processing, neurocognition, and type of symptom. Meta-analytic results indicated that facial recognition and emotion processing are strongly interrelated (r=.51). In addition, the relationship between FR and EP through voice prosody (r=.58) is as strong as the relationship between FR and EP based on facial stimuli (r=.53). Further, the relationship between emotion recognition, neurocognition, and symptoms is independent of the emotion processing modality - facial stimuli and voice prosody. The association between FR and EP that occurs through voice prosody suggests that FR is a fundamental cognitive process. The observed links between FR and EP might be due to bottom-up associations between neurocognition and EP, and not simply because most emotion recognition tasks use visual facial stimuli. In addition, links with symptoms, especially negative symptoms and disorganization, suggest possible symptom mechanisms that contribute to FR and EP deficits. © 2013 Elsevier B.V. All rights reserved.

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/.

The five-factor model of personality traits and organizational citizenship behaviors: a meta-analysis.

Science.gov (United States)

Chiaburu, Dan S; Oh, In-Sue; Berry, Christopher M; Li, Ning; Gardner, Richard G

2011-11-01

Using meta-analytic tests based on 87 statistically independent samples, we investigated the relationships between the five-factor model (FFM) of personality traits and organizational citizenship behaviors in both the aggregate and specific forms, including individual-directed, organization-directed, and change-oriented citizenship. We found that Emotional Stability, Extraversion, and Openness/Intellect have incremental validity for citizenship over and above Conscientiousness and Agreeableness, 2 well-established FFM predictors of citizenship. In addition, FFM personality traits predict citizenship over and above job satisfaction. Finally, we compared the effect sizes obtained in the current meta-analysis with the comparable effect sizes predicting task performance from previous meta-analyses. As a result, we found that Conscientiousness, Emotional Stability, and Extraversion have similar magnitudes of relationships with citizenship and task performance, whereas Openness and Agreeableness have stronger relationships with citizenship than with task performance. This lends some support to the idea that personality traits are (slightly) more important determinants of citizenship than of task performance. We conclude with proposed directions for future research on the relationships between FFM personality traits and specific forms of citizenship, based on the current findings. (c) 2011 APA, all rights reserved.

Is ADHD a Risk Factor Independent of Conduct Disorder for Illicit Substance Use? A Meta-Analysis and Meta-Regression Investigation

Science.gov (United States)

Serra-Pinheiro, Maria Antonia; Coutinho, Evandro S. F.; Souza, Isabella S.; Pinna, Camilla; Fortes, Didia; Araujo, Catia; Szobot, Claudia M.; Rohde, Luis A.; Mattos, Paulo

2013-01-01

Objective: To investigate meta-analytically if the association between ADHD and illicit substance use (ISU) is maintained when controlling for conduct disorder/oppositional-defiant disorder (CD/ODD). Method: A systematic literature review was conducted through Medline from 1980 to 2008. Data extracted and selections made by one author were…

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.

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

A meta-analysis of social skills training and related interventions for psychosis

NARCIS (Netherlands)

Turner, David T.; McGlanaghy, Edel; Cuijpers, Pim; Van Der Gaag, Mark; Karyotaki, Eirini; MacBeth, Angus

2018-01-01

Objective Evidence suggests that social skills training (SST) is an efficacious intervention for negative symptoms in psychosis, whereas evidence of efficacy in other psychosis symptom domains is limited. The current article reports a comprehensive meta-analytic review of the evidence for SST across

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.

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 effect of loving-kindness meditation on positive emotions: a meta-analytic review

Directory of Open Access Journals (Sweden)

Xianglong eZENG

2015-11-01

Full Text Available While it has been suggested that loving-kindness meditation (LKM is an effective practice for promoting positive emotions, the empirical evidence in the literature remains unclear. Here, we provide a systematic review of 24 empirical studies (N = 1759 on LKM with self-reported positive emotions. The effect of LKM on positive emotions was estimated with meta-analysis, and the influence of variations across LKM interventions was further explored with subgroup analysis and meta-regression. The meta-analysis showed that (1 medium effect sizes for LKM interventions on daily positive emotions in both wait-list controlled RCTs and non-RCT studies; and (2 small to large effect sizes for the on-going practice of LKM on immediate positive emotions across different comparisons. Further analysis showed that (1 interventions focused on loving-kindness had medium effect size, but interventions focused on compassion showed small effect sizes; (2 the length of interventions and the time spent on meditation did not influence the effect sizes, but the studies without didactic components in interventions had small effect sizes. A few individual studies reported that the nature of positive emotions and individual differences also influenced the results. In sum, LKM practice and interventions are effective in enhancing positive emotions, but more studies are needed to identify the active components of the interventions, to compare different psychological operations, and to explore the applicability in clinical populations.

Creep analysis by the path function method

International Nuclear Information System (INIS)

Akin, J.E.; Pardue, R.M.

1977-01-01

The finite element method has become a common analysis procedure for the creep analysis of structures. The most recent programs are designed to handle a general class of material properties and are able to calculate elastic, plastic, and creep components of strain under general loading histories. The constant stress approach is too crude a model to accurately represent the actual behaviour of the stress for large time steps. The true path of a point in the effective stress-effective strain (sigmasup(e)-epsilonsup(c)) plane is often one in which the slope is rapidly changing. Thus the stress level quickly moves away from the initial stress level and then gradually approaches the final one. The result is that the assumed constant stress level quickly becomes inaccurate. What is required is a better method of approximation of the true path in the sigmasup(e)-epsilonsup(c) space. The method described here is called the path function approach because it employs an assumed function to estimate the motion of points in the sigmasup(e)-epsilonsup(c) space. (Auth.)

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.

Exploring factors that influence work analysis data: A meta-analysis of design choices, purposes, and organizational context.

Science.gov (United States)

DuVernet, Amy M; Dierdorff, Erich C; Wilson, Mark A

2015-09-01

Work analysis is fundamental to designing effective human resource systems. The current investigation extends previous research by identifying the differential effects of common design decisions, purposes, and organizational contexts on the data generated by work analyses. The effects of 19 distinct factors that span choices of descriptor, collection method, rating scale, and data source, as well as project purpose and organizational features, are explored. Meta-analytic results cumulated from 205 articles indicate that many of these variables hold significant consequences for work analysis data. Factors pertaining to descriptor choice, collection method, rating scale, and the purpose for conducting the work analysis each showed strong associations with work analysis data. The source of the work analysis information and organizational context in which it was conducted displayed fewer relationships. Findings can be used to inform choices work analysts make about methodology and postcollection evaluations of work analysis information. (c) 2015 APA, all rights reserved).

Pancultural self-enhancement reloaded: a meta-analytic reply to Heine (2005).

Science.gov (United States)

Sedikides, Constantine; Gaertner, Lowell; Vevea, Jack L

2005-10-01

C. Sedikides, L. Gaertner, and Y. Toguchi (2003) reported findings favoring the universality of self-enhancement. S. J. Heine (2005) challenged the authors' research on evidential and logical grounds. In response, the authors carried out 2 meta-analytic investigations. The results backed the C. Sedikides et al. (2003) theory and findings. Both Westerners and Easterners self-enhanced tactically. Westerners self-enhanced on attributes relevant to the cultural ideal of individualism, whereas Easterners self-enhanced on attributes relevant to the cultural ideal of collectivism (in both cases, because of the personal importance of the ideal). Self-enhancement motivation is universal, although its manifestations are strategically sensitive to cultural context. The authors respond to other aspects of Heine's critique by discussing why researchers should empirically validate the comparison dimension (individualistic vs. collectivistic) and defending why the better-than-average effect is a valid measure of self-enhancement.

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.

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...

Cultural Distance and Firm Internationalization : A Meta-Analytical Review and Theoretical Implications

NARCIS (Netherlands)

Beugelsdijk, Sjoerd; Kostova, Tatiana; van Essen, M.; Kunst, Vincent; Spadafora, E.

This paper presents the most comprehensive review and meta-analysis of the literature on cultural distance and firm internationalization to date. We analyze the effects of cultural distance on key strategic decisions throughout the entire process of internationalization. For the preinvestment stage,

Social relationships and mortality risk: a meta-analytic review.

Science.gov (United States)

Holt-Lunstad, Julianne; Smith, Timothy B; Layton, J Bradley

2010-07-27

The quality and quantity of individuals' social relationships has been linked not only to mental health but also to both morbidity and mortality. This meta-analytic review was conducted to determine the extent to which social relationships influence risk for mortality, which aspects of social relationships are most highly predictive, and which factors may moderate the risk. Data were extracted on several participant characteristics, including cause of mortality, initial health status, and pre-existing health conditions, as well as on study characteristics, including length of follow-up and type of assessment of social relationships. Across 148 studies (308,849 participants), the random effects weighted average effect size was OR = 1.50 (95% CI 1.42 to 1.59), indicating a 50% increased likelihood of survival for participants with stronger social relationships. This finding remained consistent across age, sex, initial health status, cause of death, and follow-up period. Significant differences were found across the type of social measurement evaluated (psocial relationships on risk for mortality is comparable with well-established risk factors for mortality. Please see later in the article for the Editors' Summary.

Pain anticipation: an activation likelihood estimation meta-analysis of brain imaging studies.

Science.gov (United States)

Palermo, Sara; Benedetti, Fabrizio; Costa, Tommaso; Amanzio, Martina

2015-05-01

The anticipation of pain has been investigated in a variety of brain imaging studies. Importantly, today there is no clear overall picture of the areas that are involved in different studies and the exact role of these regions in pain expectation remains especially unexploited. To address this issue, we used activation likelihood estimation meta-analysis to analyze pain anticipation in several neuroimaging studies. A total of 19 functional magnetic resonance imaging were included in the analysis to search for the cortical areas involved in pain anticipation in human experimental models. During anticipation, activated foci were found in the dorsolateral prefrontal, midcingulate and anterior insula cortices, medial and inferior frontal gyri, inferior parietal lobule, middle and superior temporal gyrus, thalamus, and caudate. Deactivated foci were found in the anterior cingulate, superior frontal gyrus, parahippocampal gyrus and in the claustrum. The results of the meta-analytic connectivity analysis provide an overall view of the brain responses triggered by the anticipation of a noxious stimulus. Such a highly distributed perceptual set of self-regulation may prime brain regions to process information where emotion, action and perception as well as their related subcategories play a central role. Not only do these findings provide important information on the neural events when anticipating pain, but also they may give a perspective into nocebo responses, whereby negative expectations may lead to pain worsening. © 2014 Wiley Periodicals, Inc.

Altitude training and haemoglobin mass from the optimised carbon monoxide rebreathing method determined by a meta-analysis.

Science.gov (United States)

Gore, Christopher J; Sharpe, Ken; Garvican-Lewis, Laura A; Saunders, Philo U; Humberstone, Clare E; Robertson, Eileen Y; Wachsmuth, Nadine B; Clark, Sally A; McLean, Blake D; Friedmann-Bette, Birgit; Neya, Mitsuo; Pottgiesser, Torben; Schumacher, Yorck O; Schmidt, Walter F

2013-12-01

To characterise the time course of changes in haemoglobin mass (Hbmass) in response to altitude exposure. This meta-analysis uses raw data from 17 studies that used carbon monoxide rebreathing to determine Hbmass prealtitude, during altitude and postaltitude. Seven studies were classic altitude training, eight were live high train low (LHTL) and two mixed classic and LHTL. Separate linear-mixed models were fitted to the data from the 17 studies and the resultant estimates of the effects of altitude used in a random effects meta-analysis to obtain an overall estimate of the effect of altitude, with separate analyses during altitude and postaltitude. In addition, within-subject differences from the prealtitude phase for altitude participant and all the data on control participants were used to estimate the analytical SD. The 'true' between-subject response to altitude was estimated from the within-subject differences on altitude participants, between the prealtitude and during-altitude phases, together with the estimated analytical SD. During-altitude Hbmass was estimated to increase by ∼1.1%/100 h for LHTL and classic altitude. Postaltitude Hbmass was estimated to be 3.3% higher than prealtitude values for up to 20 days. The within-subject SD was constant at ∼2% for up to 7 days between observations, indicative of analytical error. A 95% prediction interval for the 'true' response of an athlete exposed to 300 h of altitude was estimated to be 1.1-6%. Camps as short as 2 weeks of classic and LHTL altitude will quite likely increase Hbmass and most athletes can expect benefit.

The Evolving Leadership Path of Visual Analytics

Energy Technology Data Exchange (ETDEWEB)

Kluse, Michael; Peurrung, Anthony J.; Gracio, Deborah K.

2012-01-02

This is a requested book chapter for an internationally authored book on visual analytics and related fields, coordianted by a UK university and to be published by Springer in 2012. This chapter is an overview of the leadship strategies that PNNL's Jim Thomas and other stakeholders used to establish visual analytics as a field, and how those strategies may evolve in the future.

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

Improved meta-analytic methods show no effect of chromium supplements on fasting glucose.

Science.gov (United States)

Bailey, Christopher H

2014-01-01

The trace mineral chromium has been extensively researched over the years in its role in glucose metabolism. Dietary supplement companies have attempted to make claims that chromium may be able to treat or prevent diabetes. Previous meta-analyses/systematic reviews have indicated that chromium supplementation results in a significant lowering of fasting glucose in diabetics but not in nondiabetics. A meta-analysis was conducted using an alternative measure of effect size, d(ppc2) in order to account for changes in the control group as well as the chromium group. The literature search included MEDLINE, the Cochrane Controlled Trials Register, and previously published article reviews, systematic reviews, and meta-analyses. Included studies were randomized, placebo-controlled trials in the English language with subjects that were nonpregnant adults, both with and without diabetes. Sixteen studies with 809 participants (440 diabetics and 369 nondiabetics) were included in the analysis. Screening for publication bias indicated symmetry of the data. Tests of heterogeneity indicated the use of a fixed-effect model (I² = 0 %). The analysis indicated that there was no significant effect of chromium supplementation in diabetics or nondiabetics, with a weighted average effect size of 0.02 (SE = 0.07), p = 0.787, CI 95 % = -0.12 to 0.16. Chromium supplementation appears to provide no benefits to populations where chromium deficiency is unlikely.

Social Goals and Youth Aggression: Meta-Analysis of Prosocial and Antisocial Goals

Science.gov (United States)

Samson, Jennifer E.; Ojanen, Tiina; Hollo, Alexandra

2012-01-01

To advance research evaluating the relationship between social information processing (Crick & Dodge) and youth aggression, this meta-analytic study examined associations between social goals and aggression in children in 21 separate research reports. Eligible studies provided descriptive or preintervention measurement of children's aggression and…

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 ...

UNDEUTSCH HYPOTHESIS AND CRITERIA BASED CONTENT ANALYSIS: A META-ANALYTIC REVIEW

Directory of Open Access Journals (Sweden)

Bárbara G. Amado

2015-01-01

Full Text Available The credibility of a testimony is a crucial component of judicial decision-making. Checklists of testimony credibility criteria are extensively used by forensic psychologists to assess the credibility of a testimony, and in many countries they are admitted as valid scientific evidence in a court of law. These checklists are based on the Undeutsch hypothesis asserting that statements derived from the memory of real-life experiences differ significantly in content and quality from fabricated or fictitious accounts. Notwithstanding, there is considerable controversy regarding the degree to which these checklists comply with the legal standards for scientific evidence to be admitted in a court of law (e.g., Daubert standards. In several countries, these checklists are not admitted as valid evidence in court, particularly in view of the inconsistent results reported in the scientific literature. Bearing in mind these issues, a meta-analysis was designed to test the Undeutsch hypothesis using the CBCA Checklist of criteria to discern between memories of self-experienced real-life events and fabricated or fictitious accounts. As the original hypothesis was formulated for populations of children, only quantitative studies with samples of children were considered for this study. In line with the Undeutsch hypothesis, the results showed a significant positive effect size that is generalizable to the total CBCA score, δ = 0.79. Moreover, a significant positive effect size was observed in each and all of the credibility criteria. In conclusion, the results corroborated the validity of the Undeutsch hypothesis and the CBCA criteria for discriminating between the memory of real self-experienced events and false or invented accounts. The results are discussed in terms of the implications for forensic practice. Con frecuencia, la evaluación de la fiabilidad de un testimonio se lleva a cabo mediante el uso de sistemas categoriales de análisis de contenido

Analysis Of Economic Motivation When Individuals Choose An Educational Path

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Viktor Anatolyevich Koksharov

2015-03-01

Full Text Available The authors consider the economic motivations when individuals choose an educational path. This line of research is relevant from both, the point of view of science — research of economic behavior of an individual, and the point of view of practice — allows to increase efficiency of investments in a human capital. The authors have developed the economic and mathematical model of choice of optimum educational paths by individuals. The model is realized in the software and approved on real data on more than 5,5 thousand students. For the analysis of the importance of rational economic expectations when an educational path has to be chosen, the paths chosen by students is compared and the educational paths optimum from the point of view of economic rationality are calculated. The analysis of the results has showed that mainly, the choice of educational paths happens according to the economic motivations. On the considered selection, 66 % of prospective students have chosen an optimum path from the point of view of economic preferences. The most significant factor providing development of optimum educational paths is an expectation of higher income upon completion of education — 22 % of all educational paths, and a possibility of cost-cutting of educating or state-subsidized education — 12 %. In our opinion, one of the most important practical results of the research of optimum educational path is the need to consider expectations of students and prospective student when developing a state policy of investment in human capital.

Understanding suicide risk within the Research Domain Criteria (RDoC) framework: A meta-analytic review.

Science.gov (United States)

Glenn, Catherine R; Kleiman, Evan M; Cha, Christine B; Deming, Charlene A; Franklin, Joseph C; Nock, Matthew K

2018-01-01

The field is in need of novel and transdiagnostic risk factors for suicide. The National Institute of Mental Health's Research Domain Criteria (RDoC) provides a framework that may help advance research on suicidal behavior. We conducted a meta-analytic review of existing prospective risk and protective factors for suicidal thoughts and behaviors (ideation, attempts, and deaths) that fall within one of the five RDoC domains or relate to a prominent suicide theory. Predictors were selected from a database of 4,082 prospective risk and protective factors for suicide outcomes. A total of 460 predictors met inclusion criteria for this meta-analytic review and most examined risk (vs. protective) factors for suicidal thoughts and behaviors. The overall effect of risk factors was statistically significant, but relatively small, in predicting suicide ideation (weighted mean odds ratio: wOR = 1.72; 95% CI: 1.59-1.87), suicide attempt (wOR = 1.66 [1.57-1.76), and suicide death (wOR = 1.41 [1.24-1.60]). Across all suicide outcomes, most risk factors related to the Negative Valence Systems domain, although effect sizes were of similar magnitude across RDoC domains. This study demonstrated that the RDoC framework provides a novel and promising approach to suicide research; however, relatively few studies of suicidal behavior fit within this framework. Future studies must go beyond the "usual suspects" of suicide risk factors (e.g., mental disorders, sociodemographics) to understand the processes that combine to lead to this deadly outcome. © 2017 Wiley Periodicals, Inc.

Acquisition Path Analysis for a SFR Fuel Manufacturing Facility

Energy Technology Data Exchange (ETDEWEB)

Chang, H. L.; Kwon, E. H.; Ahn, S. K.; Ko, W. I.; Kim, H. D. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The coarse acquisition path analysis does not claim to be complete, but it identifies plausible acquisition paths detailed enough to show that the acquisition path analysis can provide reasonable insights regarding the safeguardability assessment, and demonstrates the availability of safeguards tools and measures, although not complete, required for the implementation of effective and efficient safeguards, including the coverage of the nuclear energy system (NES) by multiple intrinsic features and extrinsic measures. It also identifies strengths, weaknesses and gaps of a system in the area of proliferation resistance in a generally understandable form. The acquisition path analysis demonstrates that all acceptance limits for the safeguardability, in principle, are met although the acceptance limit for the efficiency of the IAEA safeguards can be answered only at the end of the Safeguards-by-Design process, including interaction with IAEA operations. However, procedures for destructive assay (DA) for the verification by the IAEA are not defined. Target values for non-destructive assay (NDA) for this type of nuclear material are also not defined. Therefore, there is a need to finish demonstrations of NDA measurements on novel material types and material flows. The acquisition path analysis also shows some concerns that need to be assured in the system design process: e. g., the ID number of all storage containers in all storage positions can be read or checked without moving the storage container, transfer of TRU fuel and heel/scrap (product stream) should be strictly separated from transfer routes for waste, to make the transfer of TRU fuel and heel/scrap into waste container impossible, etc.

Effectiveness of cognitive behavioral therapy in the treatment of fibromyalgia syndrome: a meta-analytic literature review Effectiveness of cognitive behavioral therapy in the treatment of fibromyalgia syndrome: a meta-analytic literature review

Directory of Open Access Journals (Sweden)

A. Minelli

2012-07-01

Full Text Available Fibromyalgia (FM is a chronic disorder caused by a dysfunction of central nervous system sensitization. This syndrome is characterized by widespread pain and diffuse tenderness, but often also presents fatigue, sleep disturbances, and a whole range of symptoms such as morning stiffness, decreased physical function and dyscognition. FM is usually treated with pharmacological and non-pharmacological treatments. The non-pharmacological interventions include cognitive behavioral therapy (CBT, physiotherapy, acupuncture and patient education programs. In order to evaluate the efficacy of CBT and compare it with other non-pharmacological treatments, we performed a review of the meta-analytic literature. We evaluated the methodological quality of publications found by following the recommendations of the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data showed that CBT does not provide better results than other non-pharmacological treatments on outcomes of pain, fatigue, sleep disturbance and quality of life, at either a short or long-term evaluation. On the contrary, CBT seems to be more effective on symptoms of depression for a short period, whereas it considerably improves the pain self-management and reduces the number of visits to the doctor. The data currently available indicate that cost-effectiveness studies could help us to understand whether the reduction in the number of visits to the doctor could balance the cost of CBT to the health public system.Fibromyalgia (FM is a chronic disorder caused by a dysfunction of central nervous system sensitization. This syndrome is characterized by widespread pain and diffuse tenderness, but often also presents fatigue, sleep disturbances, and a whole range of symptoms such as morning stiffness, decreased physical function and dyscognition. FM is usually treated with pharmacological and non-pharmacological treatments. The nonpharmacological interventions include

Meta-analytic of the relationship between employee job satisfaction and customer satisfaction

OpenAIRE

Marlena León Mendoza; Carlos Ortega Maldonado

2014-01-01

A meta-analysis of the relationship between employee job satisfaction and customer satisfaction was conducted. This analysis produced statistically significant correlation for this relationship. Results suggest that the service context is a moderator of the employee job satisfaction – customer satisfaction relationship in a way that in personal services this correlation is stronger than in non-personal services. Some implications for future research are presented

Neurocognitive impairment in deficit and non-deficit schizophrenia: a meta-analysis.

Science.gov (United States)

Bora, E; Binnur Akdede, B; Alptekin, K

2017-10-01

Most studies suggested that patients with deficit schizophrenia have more severe impairment compared with patients with non-deficit schizophrenia. However, it is not clear whether deficit and non-deficit schizophrenia are associated with differential neurocognitive profiles. The aim of this meta-analytic review was to compare cognitive performances of deficit and non-deficit patients with each other and with healthy controls. In the current meta-analysis, differences in cognitive abilities between 897 deficit and 1636 non-deficit patients with schizophrenia were examined. Cognitive performances of 899 healthy controls were also compared with 350 patients with deficit and 592 non-deficit schizophrenia. Both deficit (d = 1.04-1.53) and non-deficit (d = 0.68-1.19) schizophrenia were associated with significant deficits in all cognitive domains. Deficit patients underperformed non-deficit patients in all cognitive domains (d = 0.24-0.84) and individual tasks (d = 0.39-0.93). The relationship between deficit syndrome and impairment in olfaction, social cognition, verbal fluency, and speed-based cognitive tasks were relatively stronger. Our findings suggest that there is consistent evidence for a significant relationship between deficit syndrome and more severe cognitive impairment in schizophrenia.

The 'side effects' of medicalization: a meta-analytic review of how biogenetic explanations affect stigma.

Science.gov (United States)

Kvaale, Erlend P; Haslam, Nick; Gottdiener, William H

2013-08-01

Reducing stigma is crucial for facilitating recovery from psychological problems. Viewing these problems biomedically may reduce the tendency to blame affected persons, but critics have cautioned that it could also increase other facets of stigma. We report on the first meta-analytic review of the effects of biogenetic explanations on stigma. A comprehensive search yielded 28 eligible experimental studies. Four separate meta-analyses (Ns=1207-3469) assessed the effects of biogenetic explanations on blame, perceived dangerousness, social distance, and prognostic pessimism. We found that biogenetic explanations reduce blame (Hedges g=-0.324) but induce pessimism (Hedges g=0.263). We also found that biogenetic explanations increase endorsement of the stereotype that people with psychological problems are dangerous (Hedges g=0.198), although this result could reflect publication bias. Finally, we found that biogenetic explanations do not typically affect social distance. Promoting biogenetic explanations to alleviate blame may induce pessimism and set the stage for self-fulfilling prophecies that could hamper recovery from psychological problems. Copyright © 2013 Elsevier Ltd. All rights reserved.

Critical Thinking Development in Pharmacy Education: A Meta-Analysis

Directory of Open Access Journals (Sweden)

Michael J Peeters

2016-03-01

Full Text Available Objective: The investigators aimed to summarize prior studies of critical thinking development among pharmacy students, using the California Critical Thinking Skills Test (CCTST, Health Sciences Reasoning Test (HSRT, and Defining Issues Test (DIT. Methods: Independently, two investigators (KLZ, MJP systematically searched available literature using PubMed, Google Scholar, ERIC, PsychInfo, as well as pharmacy education conference abstracts in American Journal of Pharmaceutical Education. Their search terms were ‘pharmacy’, and [‘critical thinking’, ‘HSRT’, ‘CCTST’, and ‘DIT’]. Studies included were those that investigated pharmacy students, used one of the tests (CCTST, HSRT, DIT, and used a longitudinal design with test administration at two or more time-points for the same subjects (i.e., development. On review, the CCTST and HSRT seem more foundational to analytical/critical thinking, while the DIT appears to measure moral/complex thinking. Summarizing used meta-analysis with Cohen’s d and random-effects modelling. Results: Five studies involved thinking development with 10 separate cohorts for meta-analysis (8 cohorts for CCTST, 2 for DIT, and 0 for HSRT. At 5 institutions, 407 and 1148 students were included (CCTST and DIT, respectively. For the CCTST, the overall effect was 0.33 (0.19-0.47 95%CI with some heterogeneity among study cohorts (I2=52%. For the DIT, the overall effect was -0.23 (-0.83-0.37 95%CI with considerable heterogeneity between study cohorts (I2=95%. For the CCTST and DIT, some studies showed effect-sizes greater than 0.5. Meta-analysis of the HSRT could not be conducted (i.e., 0 studies found. Implications: While measuring different aspects of “critical thinking”, the CCTST and DIT showed responsiveness to change and appear to be promising measures of cognitive development. These tests should be used in further well-designed research studies that explore strategies for improving cognitive

Social relationships and cognitive decline: a systematic review and meta-analysis of longitudinal cohort studies.

Science.gov (United States)

Kuiper, Jisca S; Zuidersma, Marij; Zuidema, Sytse U; Burgerhof, Johannes Gm; Stolk, Ronald P; Oude Voshaar, Richard C; Smidt, Nynke

2016-08-01

Although poor social relationships are assumed to contribute to cognitive decline, meta-analytic approaches have not been applied. Individual study results are mixed and difficult to interpret due to heterogeneity in measures of social relationships. We conducted a systematic review and meta-analysis to investigate the relation between poor social relationships and cognitive decline. MEDLINE, Embase and PsycINFO were searched for longitudinal cohort studies examining various aspects of social relationships and cognitive decline in the general population. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using random effects meta-analysis. Sources of heterogeneity were explored and likelihood of publication bias was assessed. We stratified analyses according to three aspects of social relationships: structural, functional and a combination of these. We identified 43 articles. Poor social relationships predicted cognitive decline; for structural (19 studies): pooled OR: 1.08 (95% CI: 1.05-1.11); functional (8 studies): pooled OR: 1.15 (95% CI: 1.00-1.32); and combined measures (7 studies): pooled OR: 1.12 (95% CI: 1.01-1.24). Meta-regression and subgroup analyses showed that the heterogeneity could be explained by the type of social relationship measurement and methodological quality of included studies. Despite heterogeneity in study design and measures, our meta-analyses show that multiple aspects of social relationships are associated with cognitive decline. As evidence for publication bias was found, the association might be overestimated and should therefore be interpreted with caution. Future studies are needed to better define the mechanisms underlying these associations. Potential causality of this prognostic association should be examined in future randomized controlled studies. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

Music-based interventions to reduce internalizing symptoms in children and adolescents: A meta-analysis.

Science.gov (United States)

Geipel, Josephine; Koenig, Julian; Hillecke, Thomas K; Resch, Franz; Kaess, Michael

2018-01-01

Existing systematic reviews provide evidence that music therapy is an effective intervention in the treatment of children and adolescents with psychopathology. The objective of the present review was to systematically review and quantify the effects of music-based interventions in reducing internalizing symptoms (i.e., depression and anxiety) in children and adolescents using a meta-analytical approach. Databases and journals were systematically screened for studies eligible for inclusion in meta-analysis on the effects of music-based interventions in reducing internalizing symptoms. A random-effect meta-analysis using standardized mean differences (SMD) was conducted. Five studies were included. Analysis of data from (randomized) controlled trials, yielded a significant main effect (Hedge's g = -0.73; 95%CI [-1.42;-0.04], Z = 2.08, p = 0.04, k = 5), indicating a greater reduction of internalizing symptoms in youth receiving music-based interventions (n = 100) compared to different control group interventions (n = 95). The existing evidence is limited to studies of low power and methodological quality. Included studies were highly heterogeneous with respect to the nature of the intervention, the measurements applied, the samples studied, and the study design. Findings indicate that music-based interventions may be efficient in reducing the severity of internalizing symptoms in children and adolescents. While these results are encouraging with respect to the application of music-based intervention, rigorous research is necessary to replicate existing findings and provide a broader base of evidence. More research adopting well controlled study designs of high methodological quality is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Does Parent-Child Interaction Therapy Reduce Future Physical Abuse? A Meta-Analysis

Science.gov (United States)

Kennedy, Stephanie C.; Kim, Johnny S.; Tripodi, Stephen J.; Brown, Samantha M.; Gowdy, Grace

2016-01-01

Objective: To use meta-analytic techniques to evaluating the effectiveness of parent-child interaction therapy (PCIT) at reducing future physical abuse among physically abusive families. Methods: A systematic search identified six eligible studies. Outcomes of interest were physical abuse recurrence, child abuse potential, and parenting stress.…

Martial arts participation and externalizing behavior in juveniles : A meta-analytic review

NARCIS (Netherlands)

Gubbels, J.; van der Stouwe, T.; Spruit, A.; Stams, G.J.J.M.

2016-01-01

Martial arts are very popular among juveniles all over the world, but the relation between martial arts and externalizing behavior in juveniles remains unclear. The current multilevel meta-analysis of 12 studies, including 94 effect sizes and N = 5949 juveniles, was conducted to examine the relation

Relationships of role stressors with organizational citizenship behavior: a meta-analysis.

Science.gov (United States)

Eatough, Erin M; Chang, Chu-Hsiang; Miloslavic, Stephanie A; Johnson, Russell E

2011-05-01

Several quantitative reviews have documented the negative relationships that role stressors have with task performance. Surprisingly, much less attention has been directed at the impact of role stressors on other aspects of job performance, such as organizational citizenship behavior (OCB). The goal of this study was to therefore estimate the overall relationships of role stressors (i.e., role ambiguity, conflict, and overload) with OCB. A meta-analysis of 42 existing studies indicated that role ambiguity and role conflict were negatively related to OCB and that these relationships were moderated by the target of OCB, type of organization, OCB rating source, and publication status. As expected, role conflict had a stronger negative relationship with OCB than it did with task performance. Finally, we found support for a path model in which job satisfaction mediated relationships of role stressors with OCB and for a positive direct relationship between role overload and OCB.

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....

Multiple Score Comparison: a network meta-analysis approach to comparison and external validation of prognostic scores

Directory of Open Access Journals (Sweden)

Sarah R. Haile

2017-12-01

Full Text Available Abstract Background Prediction models and prognostic scores have been increasingly popular in both clinical practice and clinical research settings, for example to aid in risk-based decision making or control for confounding. In many medical fields, a large number of prognostic scores are available, but practitioners may find it difficult to choose between them due to lack of external validation as well as lack of comparisons between them. Methods Borrowing methodology from network meta-analysis, we describe an approach to Multiple Score Comparison meta-analysis (MSC which permits concurrent external validation and comparisons of prognostic scores using individual patient data (IPD arising from a large-scale international collaboration. We describe the challenges in adapting network meta-analysis to the MSC setting, for instance the need to explicitly include correlations between the scores on a cohort level, and how to deal with many multi-score studies. We propose first using IPD to make cohort-level aggregate discrimination or calibration scores, comparing all to a common comparator. Then, standard network meta-analysis techniques can be applied, taking care to consider correlation structures in cohorts with multiple scores. Transitivity, consistency and heterogeneity are also examined. Results We provide a clinical application, comparing prognostic scores for 3-year mortality in patients with chronic obstructive pulmonary disease using data from a large-scale collaborative initiative. We focus on the discriminative properties of the prognostic scores. Our results show clear differences in performance, with ADO and eBODE showing higher discrimination with respect to mortality than other considered scores. The assumptions of transitivity and local and global consistency were not violated. Heterogeneity was small. Conclusions We applied a network meta-analytic methodology to externally validate and concurrently compare the prognostic properties

The Association Between Anxiety and Falls: A Meta-Analysis.

Science.gov (United States)

Hallford, David John; Nicholson, Geoff; Sanders, Kerrie; McCabe, Marita P

2017-09-01

Falls occur frequently among older adults and can lead to a range of adverse and debilitating outcomes. Although symptoms of clinical anxiety have been implicated as risk factors for falls, there is no current consensus on the empirical association between anxiety and falls. The current study aimed to address this gap in the literature by conducting a quantitative, meta-analytic review of findings from previous studies. A systematic literature search of bibliographic databases was conducted, yielding 18 studies that fit the criteria for inclusion in the meta-analysis. A random-effects model of all 18 studies showed a significant overall odds ratio of 1.53 (95% CI 1.28-1.83, p anxiety were associated with a 53% increased likelihood of falls. A high amount of variance among effect sizes was observed. Only age was identified as a moderator of this relationship in a subgroup of the samples. Clinical anxiety is associated with falls, however, further research is required to elucidate the factors that might moderate or mediate this relationship, the casual pathways through which they are related, and the associations between different types of anxiety and falls. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prospective Linkages between Peer Victimization and Externalizing Problems in Children: A Meta-Analysis

NARCIS (Netherlands)

Reijntjes, A.; Kamphuis, J.H.; Prinzie, P.; Boelen, P.A.; van der Schoot, M.; Telch, M.J.

2011-01-01

Previous meta-analytic research has shown both concurrent and prospective linkages between peer victimization and internalizing problems in youth. However, the linkages between peer victimization and externalizing problems over time have not been systematically examined, and it is therefore unknown

Solar array deployment analysis considering path-dependent behavior of a tape spring hinge

Energy Technology Data Exchange (ETDEWEB)

Kim, Kyung Won; Park, Young Jin [KAIST, Daejeon (Korea, Republic of)

2015-05-15

Solar array deployment analysis is conducted considering the path-dependent nonlinear behavior of tape spring hinge. Such hinges offer many advantages over rigid hinges; they are self-deployable, self-locking, lightweight, and simple. However, they show strongly nonlinear behavior with respect to rotation angle, making deployment analysis difficult. To accurately consider the characteristics of tape spring hinges for deployment analysis, a path-dependent path identification (PI) method for tracing the previous path of the moment is introduced. To analyze the deployment motion, the governing equation for solar array deployment is derived within the framework of Kane's dynamic equation for three deployable solar panels. The numerical solution is compared with the Recurdyn's multi-body dynamics analysis solution using experimentally measured moment-rotation profiles. Solar array deployment analysis is conducted by considering and not considering the path-dependent PI method. This simulation example shows that the proposed path-dependent PI method is very effective for accurately predicting the deployment motion.

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.

Meta-analysis is not an exact science: Call for guidance on quantitative synthesis decisions.

Science.gov (United States)

Haddaway, Neal R; Rytwinski, Trina

2018-05-01

Meta-analysis is becoming increasingly popular in the field of ecology and environmental management. It increases the effective power of analyses relative to single studies, and allows researchers to investigate effect modifiers and sources of heterogeneity that could not be easily examined within single studies. Many systematic reviewers will set out to conduct a meta-analysis as part of their synthesis, but meta-analysis requires a niche set of skills that are not widely held by the environmental research community. Each step in the process of carrying out a meta-analysis requires decisions that have both scientific and statistical implications. Reviewers are likely to be faced with a plethora of decisions over which effect size to choose, how to calculate variances, and how to build statistical models. Some of these decisions may be simple based on appropriateness of the options. At other times, reviewers must choose between equally valid approaches given the information available to them. This presents a significant problem when reviewers are attempting to conduct a reliable synthesis, such as a systematic review, where subjectivity is minimised and all decisions are documented and justified transparently. We propose three urgent, necessary developments within the evidence synthesis community. Firstly, we call on quantitative synthesis experts to improve guidance on how to prepare data for quantitative synthesis, providing explicit detail to support systematic reviewers. Secondly, we call on journal editors and evidence synthesis coordinating bodies (e.g. CEE) to ensure that quantitative synthesis methods are adequately reported in a transparent and repeatable manner in published systematic reviews. Finally, where faced with two or more broadly equally valid alternative methods or actions, reviewers should conduct multiple analyses, presenting all options, and discussing the implications of the different analytical approaches. We believe it is vital to tackle

Is computerised CBT really helpful for adult depression?-A meta-analytic re-evaluation of CCBT for adult depression in terms of clinical implementation and methodological validity.

Science.gov (United States)

So, Mirai; Yamaguchi, Sosei; Hashimoto, Sora; Sado, Mitsuhiro; Furukawa, Toshi A; McCrone, Paul

2013-04-15

Depression is a major cause of disability worldwide, and computerised cognitive behavioural therapy (CCBT) is expected to be a more augmentative and efficient treatment. According to previous meta-analyses of CCBT, there is a need for a meta-analytic revaluation of the short-term effectiveness of this therapy and for an evaluation of its long-term effects, functional improvement and dropout. Five databases were used (MEDLINE, PsycINFO, EMBASE, CENTRAL and CiNii). We included all RCTs with proper concealment and blinding of outcome assessment for the clinical effectiveness of CCBT in adults (aged 18 and over) with depression. Using Cohen's method, the standard mean difference (SMD) for the overall pooled effects across the included studies was estimated with a random effect model. The main outcome measure and the relative risk of dropout were included in the meta-analysis. Fourteen trials met the inclusion criteria, and sixteen comparisons from these were used for the largest meta-analysis ever. All research used appropriate random sequence generation and Intention-to-Treat analyses (ITT), and employed self-reported measures as the primary outcome. For the sixteen comparisons (2807 participants) comparing CCBT and control conditions, the pooled SMD was -0.48 [95% IC -0.63 to -0.33], suggesting similar effect to the past reviews. Also, there was no significant clinical effect at long follow-up and no improvement of function found. Furthermore, a significantly higher drop-out rate was found for CCBT than for controls. When including studies without BDI as a rating scale and with only modern imputation as sensitivity analysis, the pooled SMD remained significant despite the reduction from a moderate to a small effect. Significant publication bias was found in a funnel plot and on two tests (Begg's p = 0.09; Egger's p = 0.01). Using a trim and fill analysis, the SMD was -0.32 [95% CI -0.49 to -0.16]. Despite a short-term reduction in depression at post-treatment, the

Meta-analysis: Problems with Russian Publications.

Science.gov (United States)

Verbitskaya, E V

2015-01-01

Meta-analysis is a powerful tool to identify Evidence Based medical technologies (interventions) for use in every day practice. Meta-analysis uses statistical approaches to combine results from multiple studies in an effort to increase power (over individual studies), improve estimates of the size of the effect and/or to resolve uncertainty when reports disagree. Meta-analysis is a quantitative, formal study design used to systematically assess previous research studies to derive conclusions from this research. Meta-analysis may provide more precise estimate of the effect of treatment or risk factor for a disease, or other outcomes, than any individual study contributing to the pooled analysis.We have quite a substantial number of Russian medical publications, but not so many Meta-Analyses published in Russian. Russian publications are cited in English language papers not so often. A total of 90% of clinical studies included in published Meta-Analyses incorporate only English language papers. International studies or papers with Russian co-authors are published in English language. The main question is: what is the problem with inclusion of Russian medical publications in Meta-Analysis? The main reasons for this are the following: 1) It is difficult to find Russian papers, difficult to work with them and to work with Russian journals:a. There are single Russian Biomedical Journals, which are translated into English and are included in databases (PubMed, Scopus and other), despite the fact that all of them have English language abstracts.b. The majority the meta-analyses authors use in their work different citation management software such as the Mendeley, Reference Manager, ProCite, EndNote, and others. These citation management systems allow scientists to organize their own literature databases with internet searches and have adds-on for the Office programs what makes process of literature citation very convenient. The Internet sites of the majority of

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

Lack of association of poultry and eggs intake with risk of non-Hodgkin lymphoma: a meta-analysis of observational studies.

Science.gov (United States)

Dong, Y; Wu, G

2017-09-01

We carried out a meta-analysis to explore the association between poultry and eggs consumption and non-Hodgkin lymphoma (NHL) risk according to the published observational studies. A search of databases was performed in MEDLINE and EMBASE from their inception to March 2015. We derived meta-analytic estimates using random-effects models, and assessed between-study heterogeneity using the Cochran's Q and I 2 statistics. We identified a total of nine case-control and three prospective cohort studies, including 11,271 subjects with NHL. The summary relative risks for high vs. low analyses were 1.04 (95% confidence intervals [CIs]: 0.86-1.27; p heterogeneity poultry consumption and 1.15 (95% CIs: 0.87-1.51; p heterogeneity poultry consumption, whereas no significant factors were responsible for the high heterogeneity among the studies on eggs consumption. Limited data suggested a null association between consumption of poultry and eggs and NHL subtypes. Findings from our meta-analysis indicate that consumption of poultry and eggs may be not related to NHL risk. © 2016 John Wiley & Sons Ltd.

Efficacy of PPV23 in Preventing Pneumococcal Pneumonia in Adults at Increased Risk--A Systematic Review and Meta-Analysis.

Directory of Open Access Journals (Sweden)

Julia Schiffner-Rohe

Full Text Available Pneumococcal community-acquired pneumonia (pCAP is the most frequent form of pneumonia. The elderly and adults with underlying diseases are at an increased risk of developing pCAP. The 23-valent pneumococcal polysaccharide vaccine (PPV23 was licensed over 30 years ago and is recommended as the standard intervention in many countries across the globe, although its efficacy continues to be debated. We performed a meta-analysis of randomized controlled trials (RCTs to investigate the effect of PPV23 for preventing pCAP in adults ≥60 years of age.An existing Cochrane Review was updated to Oct 2014 using a systematic literature search to select appropriate RCTs. DerSimonian and Laird random-effects meta-analyses were performed and odd ratios (OR with 95%-confidence intervals (CI and p-values were calculated for the descriptive analyses. Reasons for heterogeneity were explored by subgroup analyses.Meta-analysis of PPV23 efficacy included four studies. Three of them did not demonstrate efficacy for PPV23. The body of evidence indicated statistically significant heterogeneity (I2 = 78%, p = 0.004 that could be explained by subgroup analysis by "study setting". Further effect modifiers for pCAP were "continent of trial" (p<0.01, and "method of pneumococcal diagnostics" (p = 0.001. Subgroup analyses revealed that the only study showing efficacy for PPV23 was an outlier. Overall, the validity of the meta-analytic PPV23 efficacy assessment was confirmed by the meta-analysis of all-cause CAP including six studies.Inconsistencies in PPV23 treatment effects to prevent pCAP could solely be explained by one outlier study that was performed in nursing homes in Japan. The effect modifier "method of pneumococcal diagnostics" should be interpreted carefully, since methodological weaknesses are not restricted to one special method only, which would justify the exclusion of certain studies. Overall, we conclude from our meta-analysis that to date there is no proof

The Role of Sexual Orientation in School-Based Victimization: A Meta-Analysis

Science.gov (United States)

Toomey, Russell B.; Russell, Stephen T.

2016-01-01

School-based victimization is associated with poorer developmental, academic, and health outcomes. This meta-analytic review compared the mean levels of school-based victimization experienced by sexual minority youth to those of heterosexual youth, and examined moderators of this difference. Results from 18 independent studies (N = 56,752…

Effects of incentive programs to stimulate safety belt use : a meta-analysis.

NARCIS (Netherlands)

Hagenzieker, M.P. Bijleveld, F.D. & Davidse, R.J.

1997-01-01

The effects of campaigns using tangible incentives (rewards) to promote safety belt usage have been evaluated by means of a meta-analytic approach. Two coders extracted a total number of 136 short-term and 114 long-term effect sizes and coded many other variables from 34 journal articles and

Task and person-focused leadership behaviors and team performance : A meta-analysis

NARCIS (Netherlands)

Ceri-Booms, Meltem; Curseu, P.L.; Oerlemans, L.A.G.

2017-01-01

This paper reports the results of a meta-analytic review of the relationship between person and task oriented leader behaviors, on the one hand, and team performance, on the other hand. The results, based on 89 independent samples, show a moderate positive (ρ=.33) association between both types of

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

Science.gov (United States)

Mark, Winifred; Toulopoulou, Timothea

2016-01-01

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

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

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

Types of parental involvement in CBT with anxious youth: a preliminary meta-analysis.

Science.gov (United States)

Manassis, Katharina; Lee, Trevor Changgun; Bennett, Kathryn; Zhao, Xiu Yan; Mendlowitz, Sandra; Duda, Stephanie; Saini, Michael; Wilansky, Pamela; Baer, Susan; Barrett, Paula; Bodden, Denise; Cobham, Vanessa E; Dadds, Mark R; Flannery-Schroeder, Ellen; Ginsburg, Golda; Heyne, David; Hudson, Jennifer L; Kendall, Philip C; Liber, Juliette; Masia-Warner, Carrie; Nauta, Maaike H; Rapee, Ronald M; Silverman, Wendy; Siqueland, Lynne; Spence, Susan H; Utens, Elisabeth; Wood, Jeffrey J

2014-12-01

Meta-analytic studies have not confirmed that involving parents in cognitive behavior therapy (CBT) for anxious children is therapeutically beneficial. There is also great heterogeneity in the type of parental involvement included. We investigated parental involvement focused on contingency management (CM) and transfer of control (TC) as a potential outcome moderator using a meta-analysis with individual patient data. Investigators of randomized controlled trials (RCTs) of CBT for anxious children, identified systematically, were invited to submit their data. Conditions in each RCT were coded based on type of parental involvement in CBT (i.e., low involvement, active involvement without emphasis on CM or TC, active involvement with emphasis on CM or TC). Treatment outcomes were compared using a 1-stage meta-analysis. All cases involved in active treatment (894 of 1,618) were included for subgroup analyses. Across all CBT groups, means of clinical severity, anxiety, and internalizing symptoms significantly decreased posttreatment and were comparable across groups. The group without emphasis on CM or TC showed a higher proportion with posttreatment anxiety diagnoses than the low-involvement group. Between posttreatment and 1-year follow-up, the proportion with anxiety diagnoses significantly decreased in CBT with active parental involvement with emphasis on CM or TC, whereas treatment gains were merely maintained in the other 2 groups. CBT for anxious children is an effective treatment with or without active parental involvement. However, CBT with active parental involvement emphasizing CM or TC may support long-term maintenance of treatment gains. RESULTS should be replicated as additional RCTs are published.

Allocation plasticity and plant-metal partitioning: Meta-analytical perspectives in phytoremediation

Energy Technology Data Exchange (ETDEWEB)

Audet, Patrick [Ottawa-Carleton Institute of Biology, Department of Biology, University of Ottawa, 30 Marie-Curie Street, Ottawa, ON K1N 6N5 (Canada)], E-mail: paude086@uottawa.ca; Charest, Christiane [Ottawa-Carleton Institute of Biology, Department of Biology, University of Ottawa, 30 Marie-Curie Street, Ottawa, ON K1N 6N5 (Canada)], E-mail: ccharest@uottawa.ca

2008-11-15

In this meta-analysis of plant growth and metal uptake parameters, we selected 19 studies of heavy metal (HM) phytoremediation to evaluate trends of allocation plasticity and plant-metal partitioning in roots relative to shoots. We calculated indexes of biomass allocation and metal distribution for numerous metals and plant species among four families of interest for phytoremediation purposes (e.g. Brassicaceae, Fabaceae, Poaceae, and Solanaceae). We determined that plants shift their biomass and distribute metals more to roots than shoots possibly to circumvent the challenges of increasing soil-HM conditions. Although this shift is viewed as a stress-avoidance strategy complementing intrinsic stress-tolerance, our findings indicate that plants express different levels of allocation plasticity and metal partitioning depending on their overall growth strategy and status as 'fast-grower' or 'slow-grower' species. Accordingly, we propose a conceptual model of allocation plasticity and plant-metal partitioning comparing 'fast-grower' and 'slow-grower' strategies and outlining applications for remediation practices. - This meta-analysis has revealed a shift in plant biomass and metal distribution from shoots to roots possibly to protect vital functions when subjected to metal stress.

Allocation plasticity and plant-metal partitioning: Meta-analytical perspectives in phytoremediation

International Nuclear Information System (INIS)

Audet, Patrick; Charest, Christiane

2008-01-01

In this meta-analysis of plant growth and metal uptake parameters, we selected 19 studies of heavy metal (HM) phytoremediation to evaluate trends of allocation plasticity and plant-metal partitioning in roots relative to shoots. We calculated indexes of biomass allocation and metal distribution for numerous metals and plant species among four families of interest for phytoremediation purposes (e.g. Brassicaceae, Fabaceae, Poaceae, and Solanaceae). We determined that plants shift their biomass and distribute metals more to roots than shoots possibly to circumvent the challenges of increasing soil-HM conditions. Although this shift is viewed as a stress-avoidance strategy complementing intrinsic stress-tolerance, our findings indicate that plants express different levels of allocation plasticity and metal partitioning depending on their overall growth strategy and status as 'fast-grower' or 'slow-grower' species. Accordingly, we propose a conceptual model of allocation plasticity and plant-metal partitioning comparing 'fast-grower' and 'slow-grower' strategies and outlining applications for remediation practices. - This meta-analysis has revealed a shift in plant biomass and metal distribution from shoots to roots possibly to protect vital functions when subjected to metal stress

Optimal Cotton Insecticide Application Termination Timing: A Meta-Analysis.

Science.gov (United States)

Griffin, T W; Zapata, S D

2016-08-01

The concept of insecticide termination timing is generally accepted among cotton (Gossypium hirsutum) researchers; however, exact timings are often disputed. Specifically, there is uncertainty regarding the last economic insecticide application to control fruit-feeding pests including tarnished plant bug (Lygus lineolaris (Palisot de Beauvois)), boll weevil (Anthonomus grandis), bollworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), and cotton fleahopper (Pseudatomoscelis seriatus). A systematic review of prior studies was conducted within a meta-analytic framework. Nine publicly available articles were amalgamated to develop an optimal timing principle. These prior studies reported 53 independent multiple means comparison field experiments for a total of 247 trial observations. Stochastic plateau theory integrated with econometric meta-analysis methodology was applied to the meta-database to determine the shape of the functional form of both the agronomic optimal insecticide termination timing and corresponding yield potential. Results indicated that current university insecticide termination timing recommendations are later than overall estimated timing suggested. The estimated 159 heat units (HU) after the fifth position above white flower (NAWF5) was found to be statistically different than the 194 HU termination used as the status quo recommended termination timing. Insecticides applied after 159 HU may have been applied in excess, resulting in unnecessary economic and environmental costs. Empirical results also suggested that extending the insecticide termination time by one unit resulted in a cotton lint yield increase of 0.27 kilograms per hectare up to the timing where the plateau began. Based on economic analyses, profit-maximizing producers may cease application as soon as 124 HU after NAWF5. These results provided insights useful to improve production systems by applying inputs only when benefits were expected to be in excess of the

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

Science.gov (United States)

Bornstein, Robert F.

1995-01-01

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

Intimate partner violence, common mental disorders and household food insecurity: an analysis using path analysis.

Science.gov (United States)

Moraes, Claudia Leite de; Marques, Emanuele Souza; Reichenheim, Michael Eduardo; Ferreira, Marcela de Freitas; Salles-Costa, Rosana

2016-11-01

To investigate the direct and indirect associations between psychological and physical intimate partner violence and the occurrence of common mental disorders (CMD) and how they relate to the occurrence of household food insecurity (HFI). This was a population-based cross-sectional study. Intimate partner violence was assessed using the Brazilian version of the Revised Conflict Tactics Scale (CTS2) and HFI was assessed using the Brazilian Food Insecurity Scale. The propositional analytical model was based on a review of the literature and was tested using path analysis. Duque de Caxias, Greater Rio de Janeiro, Brazil (April-December 2010). Women (n 849) who had been in a relationship in the 12 months preceding the interview. Both psychological and physical violence were found to be major risk factors of HFI. Psychological violence was associated with HFI indirectly via physical violence and CMD, and directly by an unidentified path. The effects of physical violence seemed to be manifested exclusively through CMD. Most of the variables in the propositional model related to socio-economic position, demographic characteristics, degree of women's social support and partner alcohol misuse were retained in the 'final' model, indicating that these factors contribute significantly to the increased likelihood of HFI. The results reinforce the importance of considering domestic violence and other psychosocial aspects of family life when implementing interventions designed to reduce/eradicate HFI.

Meta-analytical study of productive and nutritional interactions of mycotoxins in broilers.

Science.gov (United States)

Andretta, I; Kipper, M; Lehnen, C R; Hauschild, L; Vale, M M; Lovatto, P A

2011-09-01

A meta-analysis was carried out to study the association of mycotoxins with performance, productive indices, and organ weights in broilers. Ninety-eight papers published between 1980 and 2009 were used, totaling 1,401 diets and 37,371 animals. Meta-analysis followed 3 sequential analyses: graphical, correlation, and variance-covariance. The mycotoxin presence in diets reduced (P mycotoxins with the greatest effect on feed intake and bird growth, reducing (P mycotoxin concentration in diets and the animal age at challenge were the variables that more improved the coefficient of determination for equations to estimate mycotoxin effect on weight gain. The mycotoxin effect on growth proved to be greater in young poultry. The residual analysis revealed that 65% of the variation in weight gain was explained by feed intake. The variation in weight gain of challenged broilers in relation to nonchallenged broilers was also influenced by ingestion of nutrients such as protein and methionine. Mortality was 8.8 and 2.8 times greater (P Mycotoxins also increased (P Mycotoxins influenced broiler performance, productive indices, and organ weights. However, the magnitude of the effects varied with type and concentration of mycotoxin, animal age, and nutritional factors.

The Relationship Between Work Experience and Job Performance: A Conceptual and Meta-Analytic Review

National Research Council Canada - National Science Library

Quinones, Miguel

2001-01-01

.... To this end, we conducted a conceptual review of the work experience literature, developed a framework for measuring different facets of work experience, and conducted a meta-analysis to examine...

The influence of delaying judgments of learning on metacognitive accuracy: a meta-analytic review.

Science.gov (United States)

Rhodes, Matthew G; Tauber, Sarah K

2011-01-01

Many studies have examined the accuracy of predictions of future memory performance solicited through judgments of learning (JOLs). Among the most robust findings in this literature is that delaying predictions serves to substantially increase the relative accuracy of JOLs compared with soliciting JOLs immediately after study, a finding termed the delayed JOL effect. The meta-analyses reported in the current study examined the predominant theoretical accounts as well as potential moderators of the delayed JOL effect. The first meta-analysis examined the relative accuracy of delayed compared with immediate JOLs across 4,554 participants (112 effect sizes) through gamma correlations between JOLs and memory accuracy. Those data showed that delaying JOLs leads to robust benefits to relative accuracy (g = 0.93). The second meta-analysis examined memory performance for delayed compared with immediate JOLs across 3,807 participants (98 effect sizes). Those data showed that delayed JOLs result in a modest but reliable benefit for memory performance relative to immediate JOLs (g = 0.08). Findings from these meta-analyses are well accommodated by theories suggesting that delayed JOL accuracy reflects access to more diagnostic information from long-term memory rather than being a by-product of a retrieval opportunity. However, these data also suggest that theories proposing that the delayed JOL effect results from a memorial benefit or the match between the cues available for JOLs and those available at test may also provide viable explanatory mechanisms necessary for a comprehensive account.

Generalized causal mediation and path analysis: Extensions and practical considerations.

Science.gov (United States)

Albert, Jeffrey M; Cho, Jang Ik; Liu, Yiying; Nelson, Suchitra

2018-01-01

Causal mediation analysis seeks to decompose the effect of a treatment or exposure among multiple possible paths and provide casually interpretable path-specific effect estimates. Recent advances have extended causal mediation analysis to situations with a sequence of mediators or multiple contemporaneous mediators. However, available methods still have limitations, and computational and other challenges remain. The present paper provides an extended causal mediation and path analysis methodology. The new method, implemented in the new R package, gmediation (described in a companion paper), accommodates both a sequence (two stages) of mediators and multiple mediators at each stage, and allows for multiple types of outcomes following generalized linear models. The methodology can also handle unsaturated models and clustered data. Addressing other practical issues, we provide new guidelines for the choice of a decomposition, and for the choice of a reference group multiplier for the reduction of Monte Carlo error in mediation formula computations. The new method is applied to data from a cohort study to illuminate the contribution of alternative biological and behavioral paths in the effect of socioeconomic status on dental caries in adolescence.

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

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

Empathic accuracy and relationship satisfaction: A meta-analytic review.

Science.gov (United States)

Sened, Haran; Lavidor, Michal; Lazarus, Gal; Bar-Kalifa, Eran; Rafaeli, Eshkol; Ickes, William

2017-09-01

Empathic accuracy (EA; Ickes & Hodges, 2013) is the extent to which people accurately perceive their peers' thoughts, feelings, and other inner mental states. EA has particularly interested researchers in the context of romantic couples. Reviews of the literature suggest a possible link between romantic partners' EA and their relationship satisfaction (Ickes & Simpson, 2001; Sillars & Scott, 1983). To assess the magnitude of this association and examine possible moderators, we performed a meta-analytic review of 21 studies (total N = 2,739 participants) that examined the association between EA and satisfaction. We limited our review to studies measuring EA using the dyadic interaction paradigm (Ickes, Stinson, Bissonnette, & Garcia, 1990). We found a small but significant association between the two (r = .134, p .1). The association was also stronger in relationships of moderate length, suggesting that EA may be more meaningful when relationships are consolidating but before they become stable. Gender and procedural variations on the dyadic interaction paradigm did not moderate the association, and there was no difference depending on whether the association was between EA and perceivers' or targets' satisfaction (i.e., actor or partner effects). We discuss the implications of these findings and offer recommendations for future EA studies. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Bayesian variable selection for post-analytic interrogation of susceptibility loci.

Science.gov (United States)

Chen, Siying; Nunez, Sara; Reilly, Muredach P; Foulkes, Andrea S

2017-06-01

Understanding the complex interplay among protein coding genes and regulatory elements requires rigorous interrogation with analytic tools designed for discerning the relative contributions of overlapping genomic regions. To this aim, we offer a novel application of Bayesian variable selection (BVS) for classifying genomic class level associations using existing large meta-analysis summary level resources. This approach is applied using the expectation maximization variable selection (EMVS) algorithm to typed and imputed SNPs across 502 protein coding genes (PCGs) and 220 long intergenic non-coding RNAs (lncRNAs) that overlap 45 known loci for coronary artery disease (CAD) using publicly available Global Lipids Gentics Consortium (GLGC) (Teslovich et al., 2010; Willer et al., 2013) meta-analysis summary statistics for low-density lipoprotein cholesterol (LDL-C). The analysis reveals 33 PCGs and three lncRNAs across 11 loci with >50% posterior probabilities for inclusion in an additive model of association. The findings are consistent with previous reports, while providing some new insight into the architecture of LDL-cholesterol to be investigated further. As genomic taxonomies continue to evolve, additional classes such as enhancer elements and splicing regions, can easily be layered into the proposed analysis framework. Moreover, application of this approach to alternative publicly available meta-analysis resources, or more generally as a post-analytic strategy to further interrogate regions that are identified through single point analysis, is straightforward. All coding examples are implemented in R version 3.2.1 and provided as supplemental material. © 2016, The International Biometric Society.

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.

The Relationship between Learning Capability and Organizational Performance: A Meta-Analytic Examination

Science.gov (United States)

Goh, Swee C.; Elliott, Catherine; Quon, Tony K.

2012-01-01

Purpose: The purpose of this paper is to present a meta-analysis of a subset of published empirical research papers that measure learning capability and link it to organizational performance. It also seeks to examine both financial and non-financial performance. Design/methodology/approach: In a search of published research on learning capability…

Safety at work: a meta-analytic investigation of the link between job demands, job resources, burnout, engagement, and safety outcomes.

Science.gov (United States)

Nahrgang, Jennifer D; Morgeson, Frederick P; Hofmann, David A

2011-01-01

In this article, we develop and meta-analytically test the relationship between job demands and resources and burnout, engagement, and safety outcomes in the workplace. In a meta-analysis of 203 independent samples (N = 186,440), we found support for a health impairment process and for a motivational process as mechanisms through which job demands and resources relate to safety outcomes. In particular, we found that job demands such as risks and hazards and complexity impair employees' health and positively relate to burnout. Likewise, we found support for job resources such as knowledge, autonomy, and a supportive environment motivating employees and positively relating to engagement. Job demands were found to hinder an employee with a negative relationship to engagement, whereas job resources were found to negatively relate to burnout. Finally, we found that burnout was negatively related to working safely but that engagement motivated employees and was positively related to working safely. Across industries, risks and hazards was the most consistent job demand and a supportive environment was the most consistent job resource in terms of explaining variance in burnout, engagement, and safety outcomes. The type of job demand that explained the most variance differed by industry, whereas a supportive environment remained consistent in explaining the most variance in all industries.

Testing moderation in network meta-analysis with individual participant data.

Science.gov (United States)

Dagne, Getachew A; Brown, C Hendricks; Howe, George; Kellam, Sheppard G; Liu, Lei

2016-07-10

Meta-analytic methods for combining data from multiple intervention trials are commonly used to estimate the effectiveness of an intervention. They can also be extended to study comparative effectiveness, testing which of several alternative interventions is expected to have the strongest effect. This often requires network meta-analysis (NMA), which combines trials involving direct comparison of two interventions within the same trial and indirect comparisons across trials. In this paper, we extend existing network methods for main effects to examining moderator effects, allowing for tests of whether intervention effects vary for different populations or when employed in different contexts. In addition, we study how the use of individual participant data may increase the sensitivity of NMA for detecting moderator effects, as compared with aggregate data NMA that employs study-level effect sizes in a meta-regression framework. A new NMA diagram is proposed. We also develop a generalized multilevel model for NMA that takes into account within-trial and between-trial heterogeneity and can include participant-level covariates. Within this framework, we present definitions of homogeneity and consistency across trials. A simulation study based on this model is used to assess effects on power to detect both main and moderator effects. Results show that power to detect moderation is substantially greater when applied to individual participant data as compared with study-level effects. We illustrate the use of this method by applying it to data from a classroom-based randomized study that involved two sub-trials, each comparing interventions that were contrasted with separate control groups. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

The Effects of Exercise on Abdominal Fat and Liver Enzymes in Pediatric Obesity: A Systematic Review and Meta-Analysis.

Science.gov (United States)

González-Ruiz, Katherine; Ramírez-Vélez, Robinson; Correa-Bautista, Jorge Enrique; Peterson, Mark D; García-Hermoso, Antonio

2017-08-01

Despite the prevalence of obesity and the multiple position stands promoting exercise for the treatment of obesity and hepatic function, a meta-analytic approach has not previously been used to examine the effects in the pediatric population. The aim of the study was to determine the effectiveness of exercise interventions on abdominal fat, liver enzymes, and intrahepatic fat in overweight and obese youth. A computerized search was made using three databases. The analysis was restricted to studies that examined the effect of supervised exercise interventions on abdominal fat (visceral and subcutaneous fat), liver enzymes (alanine aminotransferase, aspartate aminotransferase, and gamma-glutamyl transferase), and intrahepatic fat. Fourteen clinical trials (1231 youths) were eligible for inclusion in this systematic review and meta-analysis. Standardized mean difference [SMD] and 95% confidence intervals (CIs) were calculated. Exercise was associated with a significant reduction in visceral (SMD = -0.661; 95% CI, -0.976 to -0.346; p exercise programs that involve aerobic exercise longer than three sessions per week. This meta-analysis supports current recommendation for physical exercise, mainly aerobic, as an effective intervention for nonalcoholic fatty liver disease progression by targeting hepatic lipid composition, visceral and subcutaneous adipose tissue. Systematic review registration: PROSPERO CRD42016042163.

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

Regularizing Feynman path integrals using the generalized Kontsevich-Vishik trace

Science.gov (United States)

Hartung, Tobias

2017-12-01

A fully regulated definition of Feynman's path integral is presented here. The proposed re-formulation of the path integral coincides with the familiar formulation whenever the path integral is well defined. In particular, it is consistent with respect to lattice formulations and Wick rotations, i.e., it can be used in Euclidean and Minkowski space-time. The path integral regularization is introduced through the generalized Kontsevich-Vishik trace, that is, the extension of the classical trace to Fourier integral operators. Physically, we are replacing the time-evolution semi-group by a holomorphic family of operators such that the corresponding path integrals are well defined in some half space of C . The regularized path integral is, thus, defined through analytic continuation. This regularization can be performed by means of stationary phase approximation or computed analytically depending only on the Hamiltonian and the observable (i.e., known a priori). In either case, the computational effort to evaluate path integrals or expectations of observables reduces to the evaluation of integrals over spheres. Furthermore, computations can be performed directly in the continuum and applications (analytic computations and their implementations) to a number of models including the non-trivial cases of the massive Schwinger model and a φ4 theory.

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.

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.

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

Science.gov (United States)

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

2009-01-01

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

Meta-analysis of the Effects of Sanitizing Treatments on Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes Inactivation in Fresh Produce

Science.gov (United States)

Prado-Silva, Leonardo; Cadavez, Vasco; Gonzales-Barron, Ursula; Rezende, Ana Carolina B.

2015-01-01

The aim of this study was to perform a meta-analysis of the effects of sanitizing treatments of fresh produce on Salmonella spp., Escherichia coli O157:H7, and Listeria monocytogenes. From 55 primary studies found to report on such effects, 40 were selected based on specific criteria, leading to more than 1,000 data on mean log reductions of these three bacterial pathogens impairing the safety of fresh produce. Data were partitioned to build three meta-analytical models that could allow the assessment of differences in mean log reductions among pathogens, fresh produce, and sanitizers. Moderating variables assessed in the meta-analytical models included type of fresh produce, type of sanitizer, concentration, and treatment time and temperature. Further, a proposal was done to classify the sanitizers according to bactericidal efficacy by means of a meta-analytical dendrogram. The results indicated that both time and temperature significantly affected the mean log reductions of the sanitizing treatment (P vegetables (for example, 3.04 mean log reductions [2.32 to 3.76] obtained for carrots). Among the pathogens, E. coli O157:H7 was more resistant to ozone (1.6 mean log reductions), while L. monocytogenes and Salmonella presented high resistance to organic acids, such as citric acid, acetic acid, and lactic acid (∼3.0 mean log reductions). With regard to the sanitizers, it has been found that slightly acidic electrolyzed water, acidified sodium chlorite, and the gaseous chlorine dioxide clustered together, indicating that they possessed the strongest bactericidal effect. The results reported seem to be an important achievement for advancing the global understanding of the effectiveness of sanitizers for microbial safety of fresh produce. PMID:26362982

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...

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.

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

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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…

A Meta-Analytic Review of Obesity Prevention in the Schools: 1997-2008

Science.gov (United States)

Cook-Cottone, Catherine; Casey, Carolyn M.; Feeley, Thomas Hugh; Baran, Jennifer

2009-01-01

A meta-analysis was conducted on school-based interventions to reduce obesity in children. Sixty-six (k = 66, N = 31,059) comparisons from 40 published studies from 1997 through 2008 were included in analyses. Results indicated a significant effect for school-based interventions with an overall weighted effect size of r = 0.05. Several moderating…

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

Anxiety disorders in children and adolescents with autistic spectrum disorders: a meta-analysis

NARCIS (Netherlands)

van Steensel, F.J.A.; Bögels, S.M.; Perrin, S.

2011-01-01

There is considerable evidence that children and adolescents with autistic spectrum disorders (ASD) are at increased risk of anxiety and anxiety disorders. However, it is less clear which of the specific DSM-IV anxiety disorders occur most in this population. The present study used meta-analytic

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.

Neurofunctional maps of the 'maternal brain' and the effects of oxytocin: a multimodal voxel-based meta-analysis.

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Rocchetti, Matteo; Radua, Joaquim; Paloyelis, Yannis; Xenaki, Lida-Alkisti; Frascarelli, Marianna; Caverzasi, Edgardo; Politi, Pierluigi; Fusar-Poli, Paolo

2014-10-01

Several studies have tried to understand the possible neurobiological basis of mothering. The putative involvement of oxytocin, in this regard, has been deeply investigated. Performing a voxel-based meta-analysis, we aimed at testing the hypothesis of overlapping brain activation in functional magnetic resonance imaging (fMRI) studies investigating the mother-infant interaction and the oxytocin modulation of emotional stimuli in humans. We performed two systematic literature searches: fMRI studies investigating the neurofunctional correlates of the 'maternal brain' by employing mother-infant paradigms; and fMRI studies employing oxytocin during emotional tasks. A unimodal voxel-based meta-analysis was performed on each database, whereas a multimodal voxel-based meta-analytical tool was adopted to assess the hypothesis that the neurofunctional effects of oxytocin are detected in brain areas implicated in the 'maternal brain.' We found greater activation in the bilateral insula extending to the inferior frontal gyrus, basal ganglia and thalamus during mother-infant interaction and greater left insular activation associated with oxytocin administration versus placebo. Left insula extending to basal ganglia and frontotemporal gyri as well as bilateral thalamus and amygdala showed consistent activation across the two paradigms. Right insula also showed activation across the two paradigms, and dorsomedial frontal cortex activation in mothers but deactivation with oxytocin. Significant activation in areas involved in empathy, emotion regulation, motivation, social cognition and theory of mind emerged from our multimodal meta-analysis, supporting the need for further studies directly investigating the neurobiology of oxytocin in the mother-infant relationship. © 2014 The Authors. Psychiatry and Clinical Neurosciences © 2014 Japanese Society of Psychiatry and Neurology.

The chicken or the egg? A meta-analysis of panel studies of the relationship between work-family conflict and strain.

Science.gov (United States)

Nohe, Christoph; Meier, Laurenz L; Sonntag, Karlheinz; Michel, Alexandra

2015-03-01

Does work-family conflict predict strain, does strain predict work-family conflict, or are they reciprocally related? To answer these questions, we used meta-analytic path analyses on 33 studies that had repeatedly measured work interference with family (WIF) or family interference with work (FIW) and strain. Additionally, this study sheds light on whether relationships between WIF/FIW and work-specific strain support the popular cross-domain perspective or the less popular matching perspective. Results showed reciprocal effects; that is, that WIF predicted strain (β = .08) and strain predicted WIF (β = .08). Similarly, FIW and strain were reciprocally related, such that FIW predicted strain (β = .03) and strain predicted FIW (β = .05). These findings held for both men and women and for different time lags between the 2 measurement waves. WIF had a stronger effect on work-specific strain than did FIW, supporting the matching hypothesis rather than the cross-domain perspective. PsycINFO Database Record (c) 2015 APA, all rights reserved.

New Insights into Signed Path Coefficient Granger Causality Analysis.

Science.gov (United States)

Zhang, Jian; Li, Chong; Jiang, Tianzi

2016-01-01

Granger causality analysis, as a time series analysis technique derived from econometrics, has been applied in an ever-increasing number of publications in the field of neuroscience, including fMRI, EEG/MEG, and fNIRS. The present study mainly focuses on the validity of "signed path coefficient Granger causality," a Granger-causality-derived analysis method that has been adopted by many fMRI researches in the last few years. This method generally estimates the causality effect among the time series by an order-1 autoregression, and defines a positive or negative coefficient as an "excitatory" or "inhibitory" influence. In the current work we conducted a series of computations from resting-state fMRI data and simulation experiments to illustrate the signed path coefficient method was flawed and untenable, due to the fact that the autoregressive coefficients were not always consistent with the real causal relationships and this would inevitablely lead to erroneous conclusions. Overall our findings suggested that the applicability of this kind of causality analysis was rather limited, hence researchers should be more cautious in applying the signed path coefficient Granger causality to fMRI data to avoid misinterpretation.

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.

Diesel engine exhaust and lung cancer risks - evaluation of the meta-analysis by Vermeulen et al. 2014.

Science.gov (United States)

Morfeld, Peter; Spallek, Michael

2015-01-01

Vermeulen et al. 2014 published a meta-regression analysis of three relevant epidemiological US studies (Steenland et al. 1998, Garshick et al. 2012, Silverman et al. 2012) that estimated the association between occupational diesel engine exhaust (DEE) exposure and lung cancer mortality. The DEE exposure was measured as cumulative exposure to estimated respirable elemental carbon in μg/m(3)-years. Vermeulen et al. 2014 found a statistically significant dose-response association and described elevated lung cancer risks even at very low exposures. We performed an extended re-analysis using different modelling approaches (fixed and random effects regression analyses, Greenland/Longnecker method) and explored the impact of varying input data (modified coefficients of Garshick et al. 2012, results from Crump et al. 2015 replacing Silverman et al. 2012, modified analysis of Moehner et al. 2013). We reproduced the individual and main meta-analytical results of Vermeulen et al. 2014. However, our analysis demonstrated a heterogeneity of the baseline relative risk levels between the three studies. This heterogeneity was reduced after the coefficients of Garshick et al. 2012 were modified while the dose coefficient dropped by an order of magnitude for this study and was far from being significant (P = 0.6). A (non-significant) threshold estimate for the cumulative DEE exposure was found at 150 μg/m(3)-years when extending the meta-analyses of the three studies by hockey-stick regression modelling (including the modified coefficients for Garshick et al. 2012). The data used by Vermeulen and colleagues led to the highest relative risk estimate across all sensitivity analyses performed. The lowest relative risk estimate was found after exclusion of the explorative study by Steenland et al. 1998 in a meta-regression analysis of Garshick et al. 2012 (modified), Silverman et al. 2012 (modified according to Crump et al. 2015) and Möhner et al. 2013. The meta-coefficient was

Effects of Mobile Devices on K-12 Students' Achievement: A Meta-Analysis

Science.gov (United States)

Tingir, S.; Cavlazoglu, B.; Caliskan, O.; Koklu, O.; Intepe-Tingir, S.

2017-01-01

In this meta-analytic study, we investigated the effects of mobile devices on student achievement in science, mathematics and reading in grades K-12. Based on our inclusion criteria, we searched the ERIC and PsycINFO databases and identified 14 peer-reviewed research articles published between 2010 and 2014. We identified the device type, subject…

Evaluation methodology for comparing memory and communication of analytic processes in visual analytics

Energy Technology Data Exchange (ETDEWEB)

Ragan, Eric D [ORNL; Goodall, John R [ORNL

2014-01-01

Provenance tools can help capture and represent the history of analytic processes. In addition to supporting analytic performance, provenance tools can be used to support memory of the process and communication of the steps to others. Objective evaluation methods are needed to evaluate how well provenance tools support analyst s memory and communication of analytic processes. In this paper, we present several methods for the evaluation of process memory, and we discuss the advantages and limitations of each. We discuss methods for determining a baseline process for comparison, and we describe various methods that can be used to elicit process recall, step ordering, and time estimations. Additionally, we discuss methods for conducting quantitative and qualitative analyses of process memory. By organizing possible memory evaluation methods and providing a meta-analysis of the potential benefits and drawbacks of different approaches, this paper can inform study design and encourage objective evaluation of process memory and communication.

Meta-analysis of Big Five personality traits in autism spectrum disorder.

Science.gov (United States)

Lodi-Smith, Jennifer; Rodgers, Jonathan D; Cunningham, Sara A; Lopata, Christopher; Thomeer, Marcus L

2018-04-01

The present meta-analysis synthesizes the emerging literature on the relationship of Big Five personality traits to autism spectrum disorder. Studies were included if they (1) either (a) measured autism spectrum disorder characteristics using a metric that yielded a single score quantification of the magnitude of autism spectrum disorder characteristics and/or (b) studied individuals with an autism spectrum disorder diagnosis compared to individuals without an autism spectrum disorder diagnosis and (2) measured Big Five traits in the same sample or samples. Fourteen reviewed studies include both correlational analyses and group comparisons. Eighteen effect sizes per Big Five trait were used to calculate two overall effect sizes per trait. Meta-analytic effects were calculated using random effects models. Twelve effects (per trait) from nine studies reporting correlations yielded a negative association between each Big Five personality trait and autism spectrum disorder characteristics (Fisher's z ranged from -.21 (conscientiousness) to -.50 (extraversion)). Six group contrasts (per trait) from six studies comparing individuals diagnosed with autism spectrum disorder to neurotypical individuals were also substantial (Hedges' g ranged from -.88 (conscientiousness) to -1.42 (extraversion)). The potential impact of personality on important life outcomes and new directions for future research on personality in autism spectrum disorder are discussed in light of results.

Clarifying Relationships among Work and Family Social Support, Stressors, and Work-Family Conflict

Science.gov (United States)

Michel, Jesse S.; Mitchelson, Jacqueline K.; Pichler, Shaun; Cullen, Kristin L.

2010-01-01

Although work and family social support predict role stressors and work-family conflict, there has been much ambiguity regarding the conceptual relationships among these constructs. Using path analysis on meta-analytically derived validity coefficients (528 effect sizes from 156 samples), we compare three models to address these concerns and…

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-analytic approaches to determine gender differences in the age-incidence characteristics of schizophrenia and related psychoses.

Science.gov (United States)

Jackson, Dan; Kirkbride, James; Croudace, Tim; Morgan, Craig; Boydell, Jane; Errazuriz, Antonia; Murray, Robin M; Jones, Peter B

2013-03-01

A recent systematic review and meta-analysis of the incidence and prevalence of schizophrenia and other psychoses in England investigated the variation in the rates of psychotic disorders. However, some of the questions of interest, and the data collected to answer these, could not be adequately addressed using established meta-analysis techniques. We developed a novel statistical method, which makes combined use of fractional polynomials and meta-regression. This was used to quantify the evidence of gender differences and a secondary peak onset in women, where the outcome of interest is the incidence of schizophrenia. Statistically significant and epidemiologically important effects were obtained using our methods. Our analysis is based on data from four studies that provide 50 incidence rates, stratified by age and gender. We describe several variations of our method, in particular those that might be used where more data is available, and provide guidance for assessing the model fit. Copyright © 2013 John Wiley & Sons, Ltd.

The Influence of Function, Topography, and Setting on Noncontingent Reinforcement Effect Sizes for Reduction in Problem Behavior: A Meta-Analysis of Single-Case Experimental Design Data

Science.gov (United States)

Ritter, William A.; Barnard-Brak, Lucy; Richman, David M.; Grubb, Laura M.

2018-01-01

Richman et al. ("J Appl Behav Anal" 48:131-152, 2015) completed a meta-analytic analysis of single-case experimental design data on noncontingent reinforcement (NCR) for the treatment of problem behavior exhibited by individuals with developmental disabilities. Results showed that (1) NCR produced very large effect sizes for reduction in…

Depression and Anxiety Prevention Based on Cognitive Behavioral Therapy for At-Risk Adolescents: A Meta-Analytic Review

Directory of Open Access Journals (Sweden)

Sanne P. A. Rasing

2017-06-01

Full Text Available Depression and anxiety disorders are among the most common mental disorders during adolescence. During this life phase, the incidence of these clinical disorders rises dramatically, and even more adolescents suffer from symptoms of depression or anxiety that are just below the clinical threshold. Both clinical and subclinical levels of depression or anxiety symptoms are related to decreased functioning in various areas, such as social and academic functioning. Prevention of depression and anxiety in adolescents is therefore imperative. We conducted a meta-analytic review of the effects of school-based and community-based prevention programs that are based on cognitive behavioral therapy with the primary goal preventing depression, anxiety, or both in high risk adolescents. Articles were obtained by searching databases and hand searching reference lists of relevant articles and reviews. The selection process yielded 32 articles in the meta-analyses. One article reported on two studies and three articles reported on both depression and anxiety. This resulted in a total of 36 studies, 23 on depression and 13 on anxiety. For depression prevention aimed at high risk adolescents, meta-analysis showed a small effect of prevention programs directly after the intervention, but no effect at 3–6 months and at 12 months follow-up. For anxiety prevention aimed at high risk adolescents, no short-term effect was found, nor at 12 months follow-up. Three to six months after the preventive intervention, symptoms of anxiety were significantly decreased. Although effects on depression and anxiety symptoms were small and temporary, current findings cautiously suggest that depression and anxiety prevention programs based on CBT might have small effects on mental health of adolescents. However, it also indicates that there is still much to be gained for prevention programs. Current findings and possibilities for future research are discussed in order to further

Testing the Strength of the Iron Cage: A Meta-Analysis of Neo-Institutional Theory

NARCIS (Netherlands)

P.P.M.A.R. Heugens (Pursey); M.W. Lander (Michel)

2007-01-01

textabstractIn this study, we use meta-analytical techniques to quantitatively synthesize and evaluate the sizeable body of empirical work that has been conducted under the banner of neo-institutional theory. We find strong support for the influence of mimetic pressures on organizational

Why does self-reported emotional intelligence predict job performance? A meta-analytic investigation of mixed EI.

Science.gov (United States)

Joseph, Dana L; Jin, Jing; Newman, Daniel A; O'Boyle, Ernest H

2015-03-01

Recent empirical reviews have claimed a surprisingly strong relationship between job performance and self-reported emotional intelligence (also commonly called trait EI or mixed EI), suggesting self-reported/mixed EI is one of the best known predictors of job performance (e.g., ρ = .47; Joseph & Newman, 2010b). Results further suggest mixed EI can robustly predict job performance beyond cognitive ability and Big Five personality traits (Joseph & Newman, 2010b; O'Boyle, Humphrey, Pollack, Hawver, & Story, 2011). These criterion-related validity results are problematic, given the paucity of evidence and the questionable construct validity of mixed EI measures themselves. In the current research, we update and reevaluate existing evidence for mixed EI, in light of prior work regarding the content of mixed EI measures. Results of the current meta-analysis demonstrate that (a) the content of mixed EI measures strongly overlaps with a set of well-known psychological constructs (i.e., ability EI, self-efficacy, and self-rated performance, in addition to Conscientiousness, Emotional Stability, Extraversion, and general mental ability; multiple R = .79), (b) an updated estimate of the meta-analytic correlation between mixed EI and supervisor-rated job performance is ρ = .29, and (c) the mixed EI-job performance relationship becomes nil (β = -.02) after controlling for the set of covariates listed above. Findings help to establish the construct validity of mixed EI measures and further support an intuitive theoretical explanation for the uncommonly high association between mixed EI and job performance--mixed EI instruments assess a combination of ability EI and self-perceptions, in addition to personality and cognitive ability. PsycINFO Database Record (c) 2015 APA, all rights reserved.

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.

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...

Semantic priming without association: a meta-analytic review.

Science.gov (United States)

Lucas, M

2000-12-01

A meta-analysis of 26 studies indicated that automatic semantic priming can occur without association. Priming did not vary substantially with differences in variables that affect automatic versus strategic processing, such as time spent processing the prime and target, relationship proportion, and task (except that average effects were smaller in the naming task). Although category coordinates were investigated in the majority of studies, synonyms, antonyms, and script relations also demonstrated priming; functional relations showed greater priming, and essential and perceptual relations showed less. The average effect size for semantic priming was smaller than that for associative priming, suggesting that there is an "associative boost" from adding an associative relationship to a semantic one. The implications of these findings for the modularity thesis and for models of semantic priming are discussed.

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...

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.

Sex differences in nicotine intravenous self-administration: A meta-analytic review.

Science.gov (United States)

Flores, Rodolfo J; Uribe, Kevin P; Swalve, Natashia; O'Dell, Laura E

2017-11-21

This report reflects a meta-analysis that systematically reviewed the literature on intravenous self-administration (IVSA) of nicotine in female and male rats. The goal was to determine if sex differences in nicotine IVSA exist, estimate the magnitude of the effect, and identify potential moderators of the relationship between sex differences and nicotine consumption. Extensive search procedures identified 20 studies that met the inclusion criteria of employing both female and male rats in nicotine IVSA procedures. The meta-analysis was conducted on effect size values that were calculated from mean total intake or nicotine deliveries using the Hedges' unbiased g u statistic. A random effects analysis revealed that overall females self-administered more nicotine than males (weighted g u =0.18, 95% CI [0.003, 0.34]). Subsequent moderator variable analyses revealed that certain procedural conditions influenced the magnitude of sex differences in nicotine IVSA. Specifically, higher reinforcement requirements (>FR1) and extended-access sessions (23h) were associated with greater nicotine IVSA in females versus males. Females also displayed higher nicotine intake than males when the experiment included a light cue that signaled nicotine delivery. Sex differences were not influenced by the diurnal phase of testing, dose of nicotine, or prior operant training. Overall, the results revealed that female rats display higher levels of nicotine IVSA than males, suggesting that the strong reinforcing effects of nicotine promote tobacco use in women. Copyright © 2017 Elsevier Inc. All rights reserved.

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

Double path-integral migration velocity analysis: a real data example

International Nuclear Information System (INIS)

Costa, Jessé C; Schleicher, Jörg

2011-01-01

Path-integral imaging forms an image with no knowledge of the velocity model by summing over the migrated images obtained for a set of migration velocity models. Double path-integral imaging migration extracts the stationary velocities, i.e. those velocities at which common-image gathers align horizontally, as a byproduct. An application of the technique to a real data set demonstrates that quantitative information about the time migration velocity model can be determined by double path-integral migration velocity analysis. Migrated images using interpolations with different regularizations of the extracted velocities prove the high quality of the resulting time-migration velocity information. The so-obtained velocity model can then be used as a starting model for subsequent velocity analysis tools like migration tomography or other tomographic methods

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.

Statistical Analysis of the First Passage Path Ensemble of Jump Processes

Science.gov (United States)

von Kleist, Max; Schütte, Christof; Zhang, Wei

2018-02-01

The transition mechanism of jump processes between two different subsets in state space reveals important dynamical information of the processes and therefore has attracted considerable attention in the past years. In this paper, we study the first passage path ensemble of both discrete-time and continuous-time jump processes on a finite state space. The main approach is to divide each first passage path into nonreactive and reactive segments and to study them separately. The analysis can be applied to jump processes which are non-ergodic, as well as continuous-time jump processes where the waiting time distributions are non-exponential. In the particular case that the jump processes are both Markovian and ergodic, our analysis elucidates the relations between the study of the first passage paths and the study of the transition paths in transition path theory. We provide algorithms to numerically compute statistics of the first passage path ensemble. The computational complexity of these algorithms scales with the complexity of solving a linear system, for which efficient methods are available. Several examples demonstrate the wide applicability of the derived results across research areas.

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

Path Transmissibility Analysis Considering Two Types of Correlations in Hydropower Stations

Directory of Open Access Journals (Sweden)

Baoping Zhi

2013-01-01

Full Text Available A new vibration model is built by introducing the head-cover vibration transfer path based on a previous analysis of the vertical vibration model for hydropower station units and powerhouses. This research focuses on disturbance- and parameter-related transfer paths in a practical situation. In a complex situation, the application of the stochastic perturbation method is expanded using an algebra synthesis method the Hadamard product, and theoretical analyses, and numerical simulations of transfer paths in the new vibration model are carried out through the expanded perturbation method. The path transfer force, the path transmissibility, and the path disturbance ranges in the frequency domain are provided. The results indicate that the methods proposed in this study can efficiently reduce the disturbance range and can accurately analyze the transfer paths of hydraulic-source vertical vibration in hydropower stations.

Neurological Soft Signs in Schizophrenia: A Meta-analysis

Science.gov (United States)

Chan, Raymond C. K.; Xu, Ting; Heinrichs, R. Walter; Yu, Yue; Wang, Ya

2010-01-01

Background: Neurological soft signs (NSS) are hypothesized as candidate endophenotypes for schizophrenia, but their prevalence and relations with clinical and demographic data are unknown. The authors undertook a quantification (meta-analysis) of the published literature on NSS in patients with schizophrenia and healthy controls. A systematic search was conducted for published articles reporting NSS and related data using standard measures in schizophrenia and healthy comparison groups. Method: A systematic search was conducted for published articles reporting data on the prevalence of NSS in schizophrenia using standard clinical rating scales and healthy comparison groups. Meta-analyses were performed using the Comprehensive Meta-analysis software package. Effect sizes (Cohen d) indexing the difference between schizophrenic patients and the healthy controls were calculated on the basis of reported statistics. Potential moderator variables evaluated included age of patient samples, level of education, sample sex proportions, medication doses, and negative and positive symptoms. Results: A total of 33 articles met inclusion criteria for the meta-analysis. A large and reliable group difference (Cohen d) indicated that, on average, a majority of patients (73%) perform outside the range of healthy subjects on aggregate NSS measures. Cognitive performance and positive and negative symptoms share 2%–10% of their variance with NSS. Conclusions: NSS occur in a majority of the schizophrenia patient population and are largely distinct from symptomatic and cognitive features of the illness. PMID:19377058

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

Science.gov (United States)

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

2018-06-01

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

Path probability of stochastic motion: A functional approach

Science.gov (United States)

Hattori, Masayuki; Abe, Sumiyoshi

2016-06-01

The path probability of a particle undergoing stochastic motion is studied by the use of functional technique, and the general formula is derived for the path probability distribution functional. The probability of finding paths inside a tube/band, the center of which is stipulated by a given path, is analytically evaluated in a way analogous to continuous measurements in quantum mechanics. Then, the formalism developed here is applied to the stochastic dynamics of stock price in finance.

Analytical and numerical analysis of frictional damage in quasi brittle materials

Science.gov (United States)

Zhu, Q. Z.; Zhao, L. Y.; Shao, J. F.

2016-07-01

Frictional sliding and crack growth are two main dissipation processes in quasi brittle materials. The frictional sliding along closed cracks is the origin of macroscopic plastic deformation while the crack growth induces a material damage. The main difficulty of modeling is to consider the inherent coupling between these two processes. Various models and associated numerical algorithms have been proposed. But there are so far no analytical solutions even for simple loading paths for the validation of such algorithms. In this paper, we first present a micro-mechanical model taking into account the damage-friction coupling for a large class of quasi brittle materials. The model is formulated by combining a linear homogenization procedure with the Mori-Tanaka scheme and the irreversible thermodynamics framework. As an original contribution, a series of analytical solutions of stress-strain relations are developed for various loading paths. Based on the micro-mechanical model, two numerical integration algorithms are exploited. The first one involves a coupled friction/damage correction scheme, which is consistent with the coupling nature of the constitutive model. The second one contains a friction/damage decoupling scheme with two consecutive steps: the friction correction followed by the damage correction. With the analytical solutions as reference results, the two algorithms are assessed through a series of numerical tests. It is found that the decoupling correction scheme is efficient to guarantee a systematic numerical convergence.

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

Mind-Sets Matter: A Meta-Analytic Review of Implicit Theories and Self-Regulation

Science.gov (United States)

Burnette, Jeni L.; O'Boyle, Ernest H.; VanEpps, Eric M.; Pollack, Jeffrey M.; Finkel, Eli J.

2013-01-01

This review builds on self-control theory (Carver & Scheier, 1998) to develop a theoretical framework for investigating associations of implicit theories with self-regulation. This framework conceptualizes self-regulation in terms of 3 crucial processes: goal setting, goal operating, and goal monitoring. In this meta-analysis, we included…

"Cancer-Related Fatigue: A Systematic and Meta-Analytic Review of Nonpharmacological Therapies for Cancer Patients:" Correction to Kangas, Bovbjerg, and Montgomery (2008)

Science.gov (United States)

Kangas, Maria; Bovbjerg, Dana H.; Montgomery, Guy H.

2009-01-01

Reports an error in "Cancer-related fatigue: A systematic and meta-analytic review of non-pharmacological therapies for cancer patients" by Maria Kangas, Dana H. Bovbjerg and Guy H. Montgomery (Psychological Bulletin, 2008[Sep], Vol 134[5], 700-741). The URL to the Supplemental Materials for the article is listed incorrectly in two places in the…

Offshore drilling effects in Brazilian SE marine sediments: a meta-analytical approach.

Science.gov (United States)

Dore, Marina Pereira; Farias, Cássia; Hamacher, Cláudia

2017-01-01

The exploration and production of oil and gas reserves often result to drill cutting accumulations on the seafloor adjacent to drill locations. In this study, the detection of drilling influence on marine sediments was performed by meta-analytical comparison between data from pre- and post-drilling surveys undertaken in offshore Campos Basin, southeast of Brazil. Besides this overall appraisal on the geochemical variables, a multivariate assessment, considering only the post-drilling data, was performed. Among the variables, fines content, carbonates, total organic carbon, barium, chromium, copper, iron, manganese, nickel, lead, vanadium, zinc, and total petroleum hydrocarbons, only barium, copper, and hydrocarbons were related to drilling impacts. In relation to the point of discharge, relative elevated levels in the post-drilling campaigns were observed preferentially up to 500 m in the northeast and southwest directions, associated to the Brazil Current-predominant direction. Other distributed concentrations in the surroundings seem to indicate the dilution and dispersion of drilling waste promoted by meteoceanographic factors.

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.

Applicant attraction to organizations and job choice: a meta-analytic review of the correlates of recruiting outcomes.

Science.gov (United States)

Chapman, Derek S; Uggerslev, Krista L; Carroll, Sarah A; Piasentin, Kelly A; Jones, David A

2005-09-01

Attracting high-performing applicants is a critical component of personnel selection and overall organizational success. In this study, the authors meta-analyzed 667 coefficients from 71 studies examining relationships between various predictors with job-organization attraction, job pursuit intentions, acceptance intentions, and job choice. The moderating effects of applicant gender, race, and applicant versus nonapplicant status were also examined. Results showed that applicant attraction outcomes were predicted by job-organization characteristics, recruiter behaviors, perceptions of the recruiting process, perceived fit, and hiring expectancies, but not recruiter demographics or perceived alternatives. Path analyses showed that applicant attitudes and intentions mediated the predictor-job choice relationships. The authors discuss the implications of these findings for recruiting theory, research, and practice. Copyright 2005 APA, all rights reserved.

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....

The effect of market orientation and its components on innovation consequences : A meta-analysis

NARCIS (Netherlands)

Grinstein, A.

While there is a rich body of research on market orientation's effect on business performance, much little attention has been given to its effect on innovation consequences. This is the first meta-analytic effort to study the independent effects of market orientation components (customer

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.

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...

CANSAR. Analytical irradiation for PCI analysis

International Nuclear Information System (INIS)

Bruet, M.; Lemaignan, C.

1984-01-01

The aim of ''CANSAR'' analytical irradiation is to evaluate the various mechanisms expected to be active during PCI failures (local concentration of fission products, fuel expansion, stress concentration induced by fuel fragment relocation, etc.). Two identical test pins, similar to classical PWR pins, but shorter, will be power-ramped in parallel. They will be filled with fuel pellets machined in various ways in order to simulate pellet fracture, relocation and preferential fission product migration path. One pin is highly instrumented with fission gas analysis, centre-line temperature and strain gauges on the cladding. The other can be unloaded between the pile cycles to perform other measurements such as diameter change, eddy currents, hot cell γ scanning. The gauges are necessary to obtain valuable information on cladding stresses. However, they induce significant modification of the thermal and mechanical behaviour of the cladding. Extensive finite element computation has been undertaken to estimate the temperature shift and the cladding reinforcement due to the gauges. Details of this work performed to design and implement the experiment will be presented. This included, in particular, high precision machining of UO 2 sectors to obtain ''precracked'' pellets and computation of the thermo-mechanical behaviour of the cladding with the gauges. (author)

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