ANNALS OF IBADAN POSTGRADUATE MEDICINE
MSc (Medical Statistics), B Tech (Comp. Sc.)
The increasing volume of information published in biomedical literatures poses an enormous challenge to evidence-based health care and scientific discoveries. It is common for important issues in medical research to be addressed in several studies. The idea of summarizing a set of studies is not new in medical literature; review articles have long had an important role in helping practitioners keep up to date and make sense of the many studies on any given topic. Meta analysis goes a step further by using statistical procedures to combine the results of several studies.
Several definitions exist in the literature. However, Glass who developed the technique defined it as the statistical analysis of a large collection of analysis results for the purpose of integrating the findings.1 Another author defined it as a statistical procedure that integrates the results of several independent studies considered to be “combinable.”2 According to Medical Subject Headings (MESH), meta-analysis is a quantitative method of combining the results of independent studies (usually drawn from published literature) and synthesizing summaries and conclusions which may be used to evaluate therapeutic effectiveness, plan new studies, etc., with application chiefly in the areas of research and medicine.3 Well conducted meta-analyses allow a more objective appraisal of the evidence than traditional narrative reviews, provide a more precise estimate of a treatment effect, and may explain heterogeneity between the results of individual studies. Ill conducted meta-analyses, on the other hand, may be biased owing to exclusion of relevant studies or inclusion of inadequate studies.4 Misleading analyses can generally be avoided if a few basic principles are observed.This review article discusses these principles, along with the steps in performing meta-analysis. It concludes by highlighting the future and role of meta- analysis in medical discoveries.
Mr. J.O. Akinyemi
Department of Epidemiology,
Medical Statistics and Environmental Health,
Faculty of Public Health,
College of Medicine,
University of Ibadan, Ibadan, Nigeria