For any systematic review related to health, here are the databases you MUST search:
Medline is a database of biomedical journal abstracts and citations from around the world. You can access Medline for free using PubMed. In some cases you’ll be able to access full text articles as well as abstracts.
The Cochrane Library contains the most extensive database of systematic reviews, as well as a curated list of clinical trials. You’ll want to use this resource to see if other researchers have conducted systematic reviews about a topic related to your questions. It can also be used to find high quality trials on most medical topics.
The following are subscription databases that are worth searching if you can access them.
Embase is also a database of biomedical research. You’ll want to use Embase as well as MEDLINE because Embase includes some international journals and publications that MEDLINE does not.
A database of abstracts and citations for behavioral and social science research.
A database for research related to nursing and allied health professionals.
As always, your librarian will help you identify the best databases for your research questions and may be able to help you access ones that require a subscription. But he or she will also remind you that it’s not enough to search for published, academic studies. You’ll also want to look for “Gray Literature.”