There are two main reasons to search for prior reviews.
You want to:
Spend a few moments (okay, maybe an hour or so!) to determine if your review has been done. It could well save you a great deal of time (and heartbreak!) later.
You will need to be affiliated with the University of Texas School of Public Health to access these resources.
Don't forget to use the appropriate SR filters if you want to limit your search to prior reviews.
This should be your starting point when trying to determine if your systematic review idea has been taken. The databases listed below cover tens of thousands of journals and even special reports that get indexed by the databases. Work efficiently-- start with journals, then look at other resources.
There are several sites with systematic review databases. One of the problems is that they often refer back to each other! It is difficult to untangle the sites, so I have tried very hard to not link to multiple sites that are searchable within 1 or 2 databases.
Many of these are indexed in Medline/PubMed. If you have not checked there first, do so! Search these sites to make sure, especially PROSPERO as it is a registry of SR protocols.
Centre for Reviews & Dissemination (University of York)
The NHS National Institute for Health Research funds high quality systematic review research. This canned search looks for all items that have the designated research type as "evidence synthesis".
To search for a specific topic, click on Advanced Search, type in 1 or 2 keywords. Don't get too fancy!
For Research Type, select Evidence Synthesis.
This will find protocols as well as completed SRs.
Agency for Health Research & Quality
For general reference assistance, please click here: http://askus.library.tmc.edu/
For Faculty and Staff consultations, please click here: http://library.tmc.edu/services/research_consultation/