382,577 papers found

OBJECTIVES: To present a novel and simple graphical approach to improve the presentation of the treatment ranking in a network meta-analysis (NMA) including multiple outcomes. STUDY DESIGN AND SETTING: NMA simultaneously compares many relevant interventions for a clinical condition from a network of trials, and allows…

BACKGROUND: Because meta-analyses are increasingly prevalent and cited in the medical literature, it is important that tools are available to assess their methodological quality. When performing an empirical study of the quality of published meta-analyses, we found that existing tools did not place a strong emphasis on…

Network meta-analysis techniques allow for pooling evidence from different studies with only partially overlapping designs for getting a broader basis for decision support. The results are network-based effect estimates that take indirect evidence into account for all pairs of treatments. The results critically depend…

BACKGROUND: We undertook a meta-analysis to evaluate the accuracy of (18)FDG PET-CT for diagnosis of distant metastases in lung cancer patients. METHODS: Studies about (18)FDG PET-CT for diagnosis of distant metastases in patients with lung cancer were systematically searched in the MEDLINE and EMBASE databases. We ca…

Meta-analysis has become central to evidence-based medicine, yet persistent misconceptions continue to distort how models are selected and interpreted. This paper identifies and clarifies six entrenched misconceptions that have shaped the practice of meta-analysis for decades. It first challenges the belief that the ch…

-value functions are modern statistical tools that unify effect estimation and hypothesis testing and can provide alternative point and interval estimates compared to standard meta-analysis methods, using any of the many-value combination procedures available (Xie et al., 2011, JASA). We provide a systematic comparison…

Effect sizes typically vary among studies of the same intervention. In a random effects meta-analysis, this source of variation is taken into account, at least to some extent. However, when we have only one study, the heterogeneity remains hidden and unaccounted for. Treating the study-level effect as if it is the popu…

Network meta-analysis (NMA) incorporates all available evidence into a general statistical framework for comparing multiple treatments. Standard NMAs make three major assumptions, namely homogeneity, similarity, and consistency, and violating these assumptions threatens an NMA's validity. In this article, we suggest a…

A random-effects model is often applied in meta-analysis when considerable heterogeneity among studies is observed due to the differences in patient characteristics, timeframe, treatment regimens, and other study characteristics. Since 2014, the journals Research Synthesis Methods and the Annals of Internal Medicine ha…

Network meta-analysis is gaining prominence in clinical epidemiology and health technology assessments that enable comprehensive assessment of comparative effectiveness for multiple available treatments. In network meta-analysis, Bayesian methods have been one of the standard approaches for the arm-based approach and a…

The growing interest in the association between dietary patterns and depression risk is reflected by an increasing number of meta-analyses conducted recently on this topic. One of these meta-analyses found no evidence of a significant association between adherence to a Mediterranean diet and depression, when using pros…

BACKGROUND: Network meta-analysis (NMA) techniques allow the comparison of a complete set of interventions for patient groups. These meta-analysis techniques may be the only source of evidence to underpin estimates of comparative efficacy. Reimbursement agencies around the world are increasingly reliant upon meta-analy…

Multivariate meta-analysis of genetic association studies and genome-wide association studies has received a remarkable attention as it improves the precision of the analysis. Here, we review, summarize and present in a unified framework methods for multivariate meta-analysis of genetic association studies and genome-w…

Publication bias can significantly limit the validity of meta-analysis when trying to draw conclusion about a research question from independent studies. Most research on detection and correction for publication bias in meta-analysis focus mainly on funnel plot-based methodologies or selection models. In this paper, we…

We review and evaluate selection methods, a prominent class of techniques first proposed by Hedges (1984) that assess and adjust for publication bias in meta-analysis, via an extensive simulation study. Our simulation covers both restrictive settings as well as more realistic settings and proceeds across multiple metri…

A bivariate copula mixed model has been recently proposed to synthesize diagnostic test accuracy studies and it has been shown that it is superior to the standard generalized linear mixed model in this context. Here, we call trivariate vine copulas to extend the bivariate meta-analysis of diagnostic test accuracy studi…

When performing a meta-analysis unexplained variation above that predicted by within study variation is usually modeled by a random effect. However, in some cases, this is not sufficient to explain all the variation because of outlier or unusual studies. A previously described method is to define an outlier as a study…

Combining data from available studies is a useful approach to interpret the overwhelming amount of data generated in medical research from multiple studies. Paradoxically, in veterinary medicine, lack of data requires integrating available data to make meaningful population inferences. Nonlinear mixed-effects modeling…

OBJECTIVES: Within technology appraisals, it is necessary to compare the complete set of treatments that may be used in the patient group under consideration. Randomized controlled trials are a key source of evidence for these comparisons. The techniques of network meta-analysis allow the networks of trial evidence to…

This study presents an overview of conceptual and practical issues of a network meta-analysis (NMA), particularly focusing on its application to randomised controlled trials with a binary outcome of interest. We start from general considerations on NMA to specifically appraise how to collect study data, structure the a…