381,725 papers found

An historical perspective of statistical methods for combining the results of independent studies is provided. The information explosion subsequent to 1950 has been a critical factor in the development of the field. An example of a meta-analysis is used to illustrate all alternative analyses that should be considered f…

The meta-analysis has become one of the predominant studies designs in orthopaedic literature. Within recent years, the network meta-analysis has been implicated as a powerful approach to comparing multiple treatments for an outcome of interest when conducting a meta-analysis (as opposed to two competing treatments whi…

The literature on the relationship between handedness and cognitive ability is riddled with studies using different conceptualizations of handedness (e.g., hand preference vs hand skill, direction vs degree, consistency vs inconsistency) and different conceptualizations of cognitive ability (intelligence vs distinct ab…

A recent meta-analysis of antidepressant trials is the largest conducted to date. Although it claims to prove antidepressant effectiveness beyond dispute, the main outcome is response rates, which are derived from continuous data in a process that can inflate differences between groups. The standardised mean difference…

Meta-analysis is a prominent method for estimating the effects of public health interventions, yet these interventions are often complex in ways that pose challenges to using conventional meta-analytic methods. This article discusses meta-analytic techniques that can be used in research syntheses on the effects of comp…

Meta-analyses are regularly used to quantitatively integrate the findings of a field, assess the consistency of an effect and make decisions based on extant research. The current article presents an overview and step-by-step tutorial of meta-analysis aimed at psychophysiological researchers. We also describe best-pract…

Meta-analysis, a statistical combination of results of several trials to produce a summary effect, has been subject to criticism in the past, mainly for the reasons of poor quality of included studies, heterogeneity between studies meta-analyzed and failing to address publication bias. These limitations can cause the r…

We study bias arising as a result of nonlinear transformations of random variables in random or mixed effects models and its effect on inference in group-level studies or in meta-analysis. The findings are illustrated on the example of overdispersed binomial distributions, where we demonstrate considerable biases arisi…

Temporal changes in magnitude of effect sizes reported in many areas of research are a threat to the credibility of the results and conclusions of meta-analysis. Numerous sequential methods for meta-analysis have been proposed to detect changes and monitor trends in effect sizes so that meta-analysis can be updated whe…

The number of systematic reviews and meta-analyses submitted to nursing and allied health journals continues to grow. Well-conducted and reported syntheses of research are valuable to advancing science. One of the common critiques identified in these manuscripts involves how the authors addressed heterogeneity among th…

Systematic reviews and meta-analysis seek to answer a pre-framed research question to lead to a valid answer through a systematic, explicit and reproducible method of locating; identifying, including and appraising appropriate trials. The results are synthesized considering the methodological rigor of included trials.…

In the practice of data analysis, there is a conceptual distinction between hypothesis testing, on the one hand, and estimation with quantified uncertainty on the other. Among frequentists in psychology, a shift of emphasis from hypothesis testing to estimation has been dubbed "the New Statistics" (Cumming 2014). A sec…

This issue of Research Synthesis Methods is devoted to discussion of the origins of modern meta-analysis. Three articles by pioneers in development meta-analysis are by Gene Glass, Frank Schmidt, and Robert Rosenthal, respectively. They reflect on their own experiences about how they made these developments. The fourth…

Meta-analysis (forest) plots are widely used to show the results from multiple individual randomized trials or observational studies that address the same question, including the assessment of screening markers. They show the between study spread of results and provide a summary estimate of the results from all the stu…