392,549 papers found

Meta-analyses can be used to comprehensively summarize the state of a given literature base, understand development and relations between constructs, and synthesize intervention effects to identify "what works for whom," all of which can directly inform research, practice, and policy. In this tutorial, we first argue t…

BACKGROUND: This study will analyze the effect of Whole Body Electromyostimulation (WB-EMS) in strength and body composition outcomes in adult population. METHODS: This study will search the following electronic databases up to July 21, 2020: PubMed, WOS, Scopus, SPORTDiscus y EMBASE. There will be no language limitat…

BACKGROUND: Studies suggested superb microvascular imaging technology to guide prostate cancer biopsy could improve the positive rate of draw materials. The present meta-analysis aimed at determining the accuracy of SMI in the location diagnosis for prostate cancer. METHODS: We will search PubMed, Web of Science, Coch…

BACKGROUND: Breast cancer is the most common malignancy in women worldwide. Compared with other malignant tumors, breast cancer patients have a higher incidence of depression and other psychiatric symptoms. The purpose of this meta-analysis was to determine the association between long-term survival and depression in p…

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 reg…

Meta-analysis has increasingly been used to identify adverse effects of drugs and vaccines, but the results have often been controversial. In one respect, meta-analysis is an especially appropriate tool in these settings. Efficacy studies are often too small to reliably assess risks that become important when a medicat…

The use of systematic review and meta-analysis of preclinical studies has become more common, including those of studies describing the modeling of cerebrovascular diseases. Empirical evidence suggests that too many preclinical experiments lack methodological rigor, and this leads to inflated treatment effects. The aim…

Systematic reviews often provide recommendations for further research. When meta-analyses are inconclusive, such recommendations typically argue for further studies to be conducted. However, the nature and amount of future research should depend on the nature and amount of the existing research. We propose a method bas…

Methodology for the meta-analysis of individual patient data with survival end-points is proposed. Motivated by questions about the reliance on hazard ratios as summary measures of treatment effects, a parametric approach is considered and percentile ratios are introduced as an alternative to hazard ratios. The general…

The form of the species richness-productivity relationship (SRPR) is both theoretically important and contentious. In an effort to distill general patterns, ecologists have undertaken meta-analyses, within which each SRPR data set is first classified into one of five alternative forms: positive, humped (unimodal), nega…

BACKGROUND: Meta-analysis of randomized controlled trials (RCTs) should provide reliable evidence about the effects of interventions. This may be less reliable when only small trials are available. METHODS: The sample size was determined for all surgical RCTs included in Cochrane Collaboration systematic reviews. The…

In meta-analysis, the assessment of graphs is widely used in an attempt to identify or rule out heterogeneity and publication bias. A variety of graphs are available for this purpose. To date, however, there has been no comparative evaluation of the performance of these graphs. With the objective of assessing the repro…

Making sense of a neuroimaging literature that is growing in scope and complexity will require increasingly sophisticated tools for synthesizing findings across studies. Meta-analysis of neuroimaging studies fills a unique niche in this process: It can be used to evaluate the consistency of findings across different la…

Recently, mixed treatment comparisons (MTC) have been presented as an extension of traditional meta-analysis by including multiple different pairwise comparisons across a range of different interventions. MTC allow for indirect comparisons and can therefore provide very useful information for clinical and reimbursement…

Dopamine D3 receptor (DRD3) binds antipsychotic drugs and is abundant in the limbic system of the brain. It has been shown to play important roles in schizophrenia. A number of studies investigated the Ser9Gly polymorphism of the DRD3 gene to test its possible association with schizophrenia; however, the results were i…

OBJECTIVES: The corpus callosum plays a pivotal role in inter-hemispheric transfer and integration of information. Magnetic resonance studies have reported callosal abnormalities in schizophrenia but findings have been inconsistent. Uncertainty has persisted despite a meta-analytic evaluation of this structure several…

We present a meta-analysis procedure for genome-wide linkage studies (MAGS). The MAGS procedure combines genome-wide linkage results across studies with possibly distinct marker maps. We applied the MAGS procedure to the simulated data from the Genetic Analysis Workshop 14 in order to investigate power to detect linkag…

Epidemiologists have gradually come to realize that repeated testing of 'causal' hypotheses normally results in inconsistent outcomes. Contradictory results pop up often enough to arouse suspicion that central epidemiological paradigms may be invalid. In this paper, we introduce complexity to explain inconsistency. Lin…

The results of meta-analysis regarding survival benefit in adjuvant chemotherapy for gastric cancer are very useful and informative in clinical practice. However, in considering the current status of adjuvant therapy the following items regarding the effects of adjuvant therapy need to be considered: (i) the assessment…

In a meta-analysis of randomized controlled trials with time-to-event outcomes, an aggregate data approach may be required for some or all included studies. Variation in the reporting of survival analyses in journals suggests that no single method for extracting the log(hazard ratio) estimate will suffice. Methods are…