MEDLINE, Embase and CINAHL
Filters are pre-written search strategies designed to retrieve a particular type of record. The Cochrane Highly Sensitive Search Strategy (HSSS) for identifying randomized trials in MEDLINE has been developed and tested and can be added to your search strategy to retrieve RCTs & quasi RCTS. There are also a Cochrane Highly Sensitive Search Strategy for identifying controlled trials in Embase, and a Cochrane CINAHL Plus filter available
See Section 4.4.7 Search filters of the Cochrane Handbook for full details of search filters and Technical Supplement to Chapter 4: Searching for and selecting studies 3.6 Search filters (page 58-63)
See also the poster from HTAi 2019
Non-Cochrane search filters
Last update: Dec 2021