[Systematic reviews in five steps: II. Identifying relevant literature].

This article focuses on the second step of a systematic review, i.e. how to identify relevant studies for the planned review. The search, using terms related to the questions framed in the previous step, should be comprehensive. However, it is important to establish selection criteria to include relevant studies and to exclude those that might present a risk of bias at this stage. Details such as broadening the spectrum of electronic databases consulted, avoiding restricting searches to a single language, managing references correctly, and recording decisions made throughout the process are winning factors for successful study identification.