Methodological aspects of meta-analysis (1)

A meta-analysis is a summary of quantitative synthesis usually used to analyze the results of the primary studies of a systematic review. In order for its conclusions to be valid, its methodology must be applied correctly, paying special attention to carrying out the bibliographical search, combining the studies in an appropriate manner and representing the results correctly. We will review in detail the aspects related to the study of heterogeneity of primary studies and the detection of publication bias, fundamental aspects for the internal validity of meta-analysis.