METAANALYSIS AND SYSTEMATIC REVIEWS IN CA RDIOLOGY

Over the last 20 years, the development of metaanalysis has been aimed at obtaining objective synthesis of the available results on specific research questions. The main achievements of metaanalysis include the application of techniques to perform systematic literature searches a nd to obtain unbiased selection of studies, data extraction and pooled estimates of effect. This paper discusses the methodologic steps to f ollow when conducting a meta-analysis, with emphasis on study selectio n, data collection and statistical methods to combine the results from individual studies. We also present a set of guided questions as an a id to critically evaluate the conclusions of published meta-analyses. The application of meta-analytic techniques to cardiology is illustrat ed using a meta-analysis of the randomized controlled trials of angiop lasty versus bypass surgery in the management of patients with ischemi c heart disease.