ABSTRACT
This chapter provides an introduction to meta-analysis for medical research workers, which requires little prior knowledge in statistics. First, some important aspects for planning meta-analyses are discussed, in particular the issue of
study selection
. Then the concept of
effect size
is introduced, and two common effect size measures are discussed (standardized treatment difference and odds ratio). The actual analysis procedure is then described in some detail for two important cases (continuous and dichotomous outcome variable). They are illustrated by a worked example. Finally, some common problems and caveats when dealing with meta-analyses are outlined and suggestions for further reading are given.
