392,528 papers found

INTRODUCTION: Past decades have seen a surge of applied and methodological research on meta-analysis. One methodological advancement that has gained significant traction is a Bayesian approach to meta-analysis. METHODS: We present a non-technical introduction to Bayesian meta-analysis. This introduction re-analyzes da…

BACKGROUND: This study will investigate the efficacy and safety of shoulder arthroscopic surgery (SAS) for patients with rotator cuff injury (RCI). METHODS: We will systematically search for randomized controlled trials in the electronic databases of PUBMED, EMBASE, Cochrane Library, CINAHL, PsycINFO, Web of Science,…

BACKGROUND: Cognitive-behavioral therapy has been considered as a means for internet addiction, but its long-term effect and the impact of internet addiction types and culture are still unclear. OBJECTIVE: This study aims to assess the efficacy of cognitive-behavior therapy for internet addiction symptoms and associat…

The point-biserial correlation is a commonly used measure of effect size in two-group designs. New estimators of point-biserial correlation are derived from different forms of a standardized mean difference. Point-biserial correlations are defined for designs with either fixed or random group sample sizes and can accom…

It is common to measure continuous outcomes using different scales (eg, quality of life, severity of anxiety or depression), therefore these outcomes need to be standardized before pooling in a meta-analysis. Common methods of standardization include using the standardized mean difference, the odds ratio derived from c…

In most cases, including those of discrete random variables, statistical meta-analysis is carried out using the normal random effect model. The authors argue that normal approximation does not always properly reflect the underlying uncertainty of the original discrete data. Furthermore, in the presence of rare events t…

BACKGROUND: The prognostic accuracy of 1H (proton) magnetic resonance spectroscopy (MRS) in neonatal hypoxic-ischemic encephalopathy has been assessed by a criticized study-based meta-analysis. An individual patient data meta-analysis may overcome some of the drawbacks encountered in the aggregate data meta-analysis. M…

Meta-analyses are methods to combine outcomes from different studies to investigate consistent effects of relatively small magnitude, which are difficult to distinguish from random variation within a single study. Several published meta-analyses addressed whether organic and conventional production methods affect the c…

BACKGROUND: Network meta-analysis is becoming increasingly popular for establishing comparative effectiveness among multiple interventions for the same disease. Network meta-analysis inherits all methodological challenges of standard pairwise meta-analysis, but with increased complexity due to the multitude of interven…

Education researchers seek to understand what works, for whom, in what circumstances. Unfortunately, educational environments are complex and research itself is highly context dependent. Faced with these challenges, some have argued that qualitative methods should supplant quantitative methods such as randomized contro…

With the rapid advances of various high-throughput technologies, generation of '-omics' data is commonplace in almost every biomedical field. Effective data management and analytical approaches are essential to fully decipher the biological knowledge contained in the tremendous amount of experimental data. Meta-analysi…

A meta-analysis of quantitative trait loci (QTL) associated with plant digestibility and cell wall composition in maize was carried out using results from 11 different mapping experiments. Statistical methods implemented in "MetaQTL" software were used to build a consensus map, project QTL positions and perform meta-an…

The purpose was to conduct a structured review and meta-analysis to determine the cumulative effect of bilateral arm training on motor capabilities post stroke. Forty-eight stroke studies were selected from three databases with 25 comparisons qualifying for inclusion in our meta-analysis. We identified and coded four t…

OBJECTIVE: Meta-analysis yields a biased result if published studies represent a biased selection of the evidence. Copas proposed a selection model to assess the sensitivity of meta-analysis conclusions to possible selection bias. An alternative proposal is the trim-and-fill method. This article reports an empirical co…

BACKGROUND: The exponential rise in published medical research on a yearly basis demands a method to summarise best evidence towards its application to patient care in clinical practice. A robust meta-analysis is a valid tool. It is often considered to be a simple process of pooling results from different studies. This…

Systematic reviews with meta-analysis of studies on diagnostic tests or prognostic factors are research tools that are still being developed. The objective of the present paper is to describe the methodology of systematic review and meta-analysis of this type of studies, step by step. A literature review on the subject…

CONTEXT: Meta-analyses are commonly performed on quasi-experimental studies in medical education and other applied field settings, with little or no apparent concern for biases and confounds present in the studies synthesised. The implicit assumption is that the biases and confounds are randomly distributed across the…

The use of standard univariate fixed- and random-effects models in meta-analysis has become well known in the last 20 years. However, these models are unsuitable for meta-analysis of clinical trials that present multiple survival estimates (usually illustrated by a survival curve) during a follow-up period. Therefore,…

BACKGROUND: Risk for complex disease is thought to be controlled by multiple genetic risk factors, each with small individual effects. Meta-analyses of several independent studies may be helpful to increase the ability to detect association when effect sizes are modest. Although many software options are available for…

Meta-analysis is a powerful statistical technique that combines the results of independent studies to identify general trends. When the species under examination are not independent however, it is also necessary to incorporate phylogenetic information into the analysis. Unfortunately, current meta-analytic approaches c…