A guide to systematic literature reviews

Each year millions of papers are published reporting the results of medical research, making it virtually impossible for clinicians to keep up to date with the latest developments. However, it is important that clinical practice is based on the best available evidence and that effective treatments should be introduced as quickly as possible for the benefit of patients. Systematic reviews are different from traditional literature reviews because they aim to identify all studies (published and unpublished) that address a specific question and their methodology has been developed to minimize the effect of selection, publication and data extraction bias. In this guide to systematic literature reviews, the methods of conducting systematic reviews are discussed in relation to minimizing bias, searching the literature and investigating heterogeneity.