392,549 papers found

BACKGROUND: Adequately conducted systematic reviews with meta-analyses are considered the highest level of evidence and thus directly defines many clinical guidelines. However, the risks of type I and II errors in meta-analyses are substantial. Trial Sequential Analysis is a method for controlling these risks. Erroneou…

Systematic reviews and meta-analyses are often considered the highest level of evidence, with high impact on clinical practice guidelines. The methodological literature on systematic reviews and meta-analyses is extensive and covers most aspects relevant to the design and interpretation of meta-analysis findings in gen…

Standard meta-analysis methods are vulnerable to bias from incomplete reporting of results (both publication and outcome reporting bias) and poor study quality. Several alternative methods have been proposed as being less vulnerable to such biases. To evaluate these claims independently we simulated study results under…

Network meta-analyses (NMAs) simultaneously estimate the effects of multiple possible treatment options for a given clinical presentation. For allergists to benefit optimally from NMAs, they must understand the process and be able to interpret the results. Through a worked example published in Pediatric Allergy and Imm…

Meta-analysis is a powerful and important tool to synthesize the literature about a research topic. Like other kinds of research, meta-analyses must be reproducible to be compliant with the principles of the scientific method. Furthermore, reproducible meta-analyses can be easily updated with new data and reanalysed ap…

OBJECTIVE: To assess the methodological quality and the consideration of heterogeneity in systematic reviews (SRs). STUDY DESIGN AND SETTING: We conducted a methodological study (CRD42019134904) and searched three databases from January 2010 to July 2019. Interventional SRs with a statistically significant meta-analys…

There exists a variety of interval estimators for the overall treatment effect in a random-effects meta-analysis. A recent literature review summarizing existing methods suggested that in most situations, the Hartung-Knapp/Sidik-Jonkman (HKSJ) method was preferable. However, a quantitative comparison of those methods i…

INTRODUCTION: The superiority of primary arthrodesis (PA) versus open reduction and internal fixation (ORIF) in Lisfranc injuries has been debated. Meta-analyses comparing these surgical options have reached contradicting conclusions. The goal of this article is to determine why different conclusions were reached and p…

Understanding both the placebo response and the underlying disease progression is crucial to designing clinical trials and interpreting results in Alzheimer's disease (AD) research. The disease severity at different stage of disease (e.g., mild cognitive impairment (MCI), early or late AD) is related to the rate of dis…

INTRODUCTION: In the field of adolescent development, meta-analysis offers valuable tools for synthesizing and assessing cumulative research evidence on the effectiveness of programs, practices, and policies intended to promote healthy adolescent development. When examining the impact of a program implemented across mu…

INTRODUCTION: Pancreatic surgery is a large and complex field of research. Several evidence gaps exist for specific diseases or surgical procedures. An overview on existing knowledge is needed to plan and prioritise future research. The aim of this project is to create a systematic and living evidence map of pancreatic…

As defined by the Cochrane Collaboration, a systematic review is a review of evidence with a clearly formulated question that uses systematic and explicit methods to identify, select, and critically appraise relevant primary research, and to extract and analyze data from the studies that are included in the review. Met…

The random-effects model, applied in most meta-analyses nowadays, typically assumes normality of the distribution of the effect parameters. The purpose of this study was to examine the performance of various random-effects methods (standard method, Hartung's method, profile likelihood method, and bootstrapping) for com…

AIM: Investigate the correlation between paraoxonase 2 (PON2) Ser311Cys polymorphism as well as the peroxisome proliferator-activated receptor gamma (PPARG) His477His polymorphism and the susceptibility to development of coronary heart diseases (CHD) through a meta-analysis. METHODS: Odds ratio and the correspond…

Outcome reporting bias occurs when outcomes in research studies are selectively reported, the selection being influenced by the study results. For benefit outcomes, we have shown how risk assessments using the Outcome Reporting Bias in Trials risk classification scale can be used to calculate bias-adjusted treatment ef…

This article presents a methodological review of 54 meta-analyses of the effectiveness of clinical psychological treatments, using standardized mean differences as the effect size index. We statistically analyzed the distribution of the number of studies of the meta-analyses, the distribution of the sample sizes in the…

Meta-analysis of neuroimaging results has proven to be a popular and valuable method to study human brain functions. A number of studies have used meta-analysis to parcellate distinct brain regions. A popular way to perform meta-analysis is typically based on the reported activation coordinates from a number of publish…

Meta-analysis is an important tool for synthesizing research on a variety of topics in ecology and evolution, including molecular ecology, but can be susceptible to nonindependence. Nonindependence can affect two major interrelated components of a meta-analysis: (i) the calculation of effect size statistics and (ii) th…

OBJECTIVE: The objective was to estimate the presence and extent to which potentially unnecessary and therefore maybe wasteful clinical trials regarding relevant interventions and outcomes in major clinical areas had been conducted. STUDY DESIGN AND SETTING: From current Cochrane collaboration systematic reviews in ma…

OBJECTIVES: In randomized controlled clinical trials, continuous outcomes are typically measured at both baseline and follow-up, and mean difference could be estimated using the change scores from baseline or the follow-up scores. This study assesses the impact of using change score vs. follow-up score on the conclusio…