392,350 papers found

We provide a step-by-step guide on conducting a quantitative systematic review (i.e., meta-analysis) using the open-source programming language R, as well as conducting a multilevel meta-analysis, in contexts where effect sizes are non-independent (e.g., multiple studies from the same lab). Quantitative systematic revi…

RATIONALE: Meta-analysis is central to evidence-based medicine, yet the implications of model choice remain poorly understood among clinicians. The distinction between fixed-effect and random-effects models is often treated as a technical detail, although it fundamentally defines the scope of inference. AIMS AND OBJEC…

PURPOSE: Systematic reviews of interventions are published each year evaluating rehabilitation approaches such as exercise, manual therapy, or electrotherapy. Currently, important methodological approaches are available to make systematic reviews more robust and transparent. One of these approaches is the Grading of Re…

Outcomes of meta-analyses are increasingly used to inform evidence-based decision making in various research fields. However, a number of recent studies have reported rapid temporal changes in magnitude and significance of the reported effects which could make policy-relevant recommendations from meta-analyses to quick…

In this paper, we show how the methods of systematic reviewing and meta-analysis can be used in conjunction with structural equation modeling to summarize the results of studies in a way that will facilitate the theory development and testing needed to advance prevention science. We begin with a high-level overview of…

OBJECTIVE: To assess how items relevant for the assessment of the generalizability of findings from randomized controlled trials were recorded in systematic reviews published in leading general medical journals. METHODS: All systematic reviews and meta-analyses published in the Annals of Internal Medicine, BMJ, JAMA (…

This systematic review of overlapping meta-analyses was conducted to propose a principle to make decisions for comparing clinical safety and efficacy of surgical and non-surgical treatment for displaced 3-part and 4-part fractures of the proximal humerus. Three electronic databases (PubMed, EMBASE, and the Cochrane Lib…

We describe an exact, unconditional, non-randomized procedure for producing confidence intervals for the grand mean in a normal-normal random effects meta-analysis. The procedure targets meta-analyses based on too few primary studies,, say, to allow for the conventional asymptotic estimators, e.g., DerSimonian and Lair…

This commentary aims to discuss the impact of publication bias on the estimated effect of prototypic antidepressants in the forced swim test (FST). A systematic review and meta-analysis (SRMA) recently reported by Kara et al. (2018) showed that selected prototypic antidepressants reduced immobility time of mice in the…

BACKGROUND: Methodological rigor is a fundamental factor in the validity and credibility of the results of a meta-analysis. AIM: Following an increasing interest in single-case experimental design (SCED) meta-analyses, the current study investigates the methodological quality of SCED meta-analyses. METHODS AND PROCED…

Prospective randomized controlled trials are difficult to obtain if a promising new therapy has to be tested against seemingly obsolete alternatives. One method to address this problem is to compare the results of (multicentre) trials to literature results. However, previous treatment-era changes and population-depende…

The unrealistically high rate of positive results within psychology has increased the attention to replication research. However, researchers who conduct a replication and want to statistically combine the results of their replication with a statistically significant original study encounter problems when using traditi…

INTRODUCTION: Sleep and mental health go hand-in-hand, with many, if not all, mental health problems being associated with problems sleeping. Although sleep has been traditionally conceptualised as a secondary consequence of mental health problems, contemporary views prescribe a more influential, causal role of sleep i…

BACKGROUND: In the first stage of meta-analytic structural equation modeling (MASEM), researchers synthesized studies using univariate meta-analysis (UM) and multivariate meta-analysis (MM) approaches. The MM approaches are known to be of better performance than the UM approaches in the meta-analysis with equal sized s…

Mendelian randomization (MR) requires strong assumptions about the genetic instruments, of which the most difficult to justify relate to pleiotropy. In a two-sample MR, different methods of analysis are available if we are able to assume, M: no pleiotropy (fixed effects meta-analysis), M: that there may be pleiotropy b…

Recently, the number of clinical prediction models sharing the same regression task has increased in the medical literature. However, evidence synthesis methodologies that use the results of these regression models have not been sufficiently studied, particularly in meta-analysis settings where only regression coeffici…

The aim of this study was to elucidate the clinicopathological characteristics of the micropapillary (MP) subtype and its correlation with survival in lung adenocarcinoma. We investigated the clinicopathological characteristics, including the incidence, sex, smoking history, tumor size, lymph node metastasis, lymphovas…

Mendelian randomization (MR) uses genetic data to probe questions of causality in epidemiological research, by invoking the Instrumental Variable (IV) assumptions. In recent years, it has become commonplace to attempt MR analyses by synthesising summary data estimates of genetic association gleaned from large and indep…

When meta-analysing intervention effects calculated from continuous outcomes, meta-analysts often encounter few trials, with potentially a small number of participants, and a variety of trial analytical methods. It is important to know how these factors affect the performance of inverse-variance fixed and DerSimonian a…