The Cochrane highly sensitive search strategies for identifying randomized trials in PubMed
Not all randomised conrolled trials have been indexed as RCTs in MEDLINE. There is a validated filter in the Cochrane Handbook for both PubMed and Ovid interfaces1.
Sensitivity-maximizing version (2008 revision); PubMed format
#1 randomized controlled trial [pt]
#2 controlled clinical trial [pt]
#3 randomized [tiab]
#4 placebo [tiab]
#5 drug therapy [sh]
#6 randomly [tiab]
#7 trial [tiab]
#8 groups [tiab]
#9 #1 OR #2 OR #3 OR #4 OR #5 OR #6 OR #7 OR #8
#10 animals [mh] NOT humans [mh]
#11 #9 NOT #10
Direct link to PubMed with sensitivity-maximizing version (2008 revision)
sensitivity- and precision-maximizing version (2008 revision); PubMed format
#1 randomized controlled trial [pt]
#2 controlled clinical trial [pt]
#3 randomized [tiab]
#4 placebo [tiab]
#5 clinical trials as topic [mesh: noexp]
#6 randomly [tiab]
#7 trial [ti]
#8 #1 OR #2 OR #3 OR #4 OR #5 OR #6 OR #7
#9 animals [mh] NOT humans [mh]
#10 #8 NOT #9
Direct link to PubMed with sensitivity- and precision-maximizing version (2008 revision)
1 Lefebvre C, Manheimer E, Glanville J. Chapter 6: Searching for studies. In: Higgins J, Green S (editors). Cochrane Handbook for Systematic Reviews of Interventions. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available from www.cochrane-handbook.org