Step 1: Which is the available evidence to answer the question of interest?
This step seeks to define the evidence that is available to answer your question. Therefore, you should have the results of the evidence search that you have carried out to answer the selected PICO* on hand. Keep in mind that this synthesis is being carried out to inform health decisions. You should make an effort to identify, evaluate and summarize the body of evidence available for the outcomes of interest. For this purpose we suggest to start by identifying summarized evidence (e.g., systematic reviews of the literature) and then, in a stepwise manner, searching for primary studies. Searching trials registers at this point is highly recommended.
To rapidly identify systematic reviews, you can use the Epistemonikos database, and for randomized controlled trials (RCTs) as primary studies, you can conduct your search in the Cochrane Central Register of Controlled Trials (CENTRAL), or in Pubmed using an appropriate filter.