Understanding the fundamental concepts for interpreting or conducting meta-analyses

Meta-analysis has become an increasingly popular method of quantifying overall drug treatment effects and of enhancing the information obtained through traditional literature review. By statistically combining several individual study results into an aggregate result, the meta-analysis method becomes particularly beneficial when evaluating multiple studies reporting outcomes. Because of the increasing number of meta-analysis studies, it is important that those reading the studies or conducting their own study comprehend some of the their basic concepts and pitfalls. This article reviews the steps of a meta-analysis method and illustrates the steps with a simple example of clonidine's use in smoking cessation.