Bayesian approach for meta - analysis of controlled clinical trials

Exploring heterogeneity in meta-analyses: needs, resources and challenges

The investigation of heterogeneity remains an essential but difficult issue in the conduct of meta-analysis. We reviewed standard and graphical methods used to explore heterogeneity in meta-analysis and publications from January 2005 to April 2007 regarding meta-analyses that focused on perinatal health topics. We assessed their approaches to the investigation of heterogeneity, including: (1) whether statistical testing for heterogeneity was performed and, if so, which test was used, (2) how a finding of statistically significant heterogeneity was handled, and (3) how the analyses were conducted in the presence of heterogeneity.

Bayesian methods in meta-analysis and evidence synthesis

This paper reviews the use of Bayesian methods in meta-analysis. Whilst there has been an explosion in the use of meta-analysis over the last few years, driven mainly by the move towards evidence-based healthcare, so too Bayesian methods are being used increasingly within medical statistics. Whilst in many meta-analysis settings the Bayesian models used mirror those previously adopted in a frequentist formulation, there are a number of specific advantages conferred by the Bayesian approach. These include: full allowance for all parameter uncertainty in the model, the ability to include other pertinent information that would otherwise be excluded, and the ability to extend the models to accommodate more complex, but frequently occurring, scenarios. The Bayesian methods discussed are illustrated by means of a meta-analysis examining the evidence relating to electronic fetal heart rate monitoring and perinatal mortality in which evidence is available from a variety of sources.

Meta-analysis and prospective meta-analysis in childhood leukemia clinical research

In this paper, we consider the role of meta-analysis and 'prospective meta-analysis' studies in childhood acute lymphocytic leukemia (ALL). In this issue, Valsecchi and Masera [1] give a thoughtful discourse, generally favorable to this approach. This article presents the opposite point of view. The aims of our article are to present the implications in clinical, rather than biostatistical terms, and to provide an extensive literature review of the subject of meta-analysis. We conclude that treatment assessments, resulting from meta-analysis of closed studies (retrospective) should be met with healthy skepticism. Trials requiring international resources should be true intergroup trials with a single coordinating center, rather than prospective meta-analysis, unless it is a question grafted onto each group's own research agenda. For example, each group might ask its own systemic control question, but a CNS protection question is asked collectively.