The following filters were created and validated by the Cochrane Collaboration and are listed on the Cochrane Work Review Group website:
(randomized controlled trial[pt] OR controlled clinical trial[pt] OR randomized[tiab] OR placebo[tiab] OR drug therapy[sh] OR randomly[tiab] OR trial[tiab] OR groups[tiab] NOT (animals [mh] NOT humans [mh]))
(randomized controlled trial[pt] OR controlled clinical trial[pt] OR randomized[tiab] OR placebo[tiab] OR clinical trials as topic[mesh:noexp] OR randomly[tiab] OR trial[ti] NOT (animals[mh] NOT humans [mh]))
A validated Embase RCT filter is in development. Until a validated filter is available, the Cochrane Handbook (Part 2, Section 22.214.171.124 - Search filters for identifying randomized trials in EMBASE), recommends two sources for filters. Please consult each source to decide which filter is most appropriate for your topic.
'crossover procedure':de OR 'double-blind procedure':de OR 'randomized controlled trial':de OR 'single-blind procedure':de OR (random* OR factorial* OR crossover* OR cross NEXT/1 over* OR placebo* OR doubl* NEAR/1 blind* OR singl* NEAR/1 blind* OR assign* OR allocat* OR volunteer*):de,ab,ti
Source: Lefebvre C, Eisinga A, McDonald S, Paul N. Enhancing access to reports of randomized trials published world-wide - the contribution of EMBASE records to the Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library. Emerging Themes in Epidemiology 2008; 5:13.
Sensitivity Maximizing Strategy
random*:ab,ti OR (clinical NEXT/1 trial*):de,ab,ti OR 'health care quality'/exp
Specificity Maximizing Strategy
(double NEXT/1 blind*):de,ab,ti OR placebo*:ab,ti OR blind*:ab,ti
Best Optimization of Sensitivity and Specificity
random*:ab,ti OR placebo*:de,ab,ti OR (double NEXT/1 blind*):ab,ti
Source: Wong SS, Wilczynski NL, Haynes RB. Developing optimal search strategies for detecting clinically sound treatment studies in EMBASE. Journal of the Medical Library Association 2006; 94(1): 41-47.
Note that the filters provided in Lefebvre et al.and Wong et al. are for use in Embase on the Ovid platform. The Cochrane Work Group has translated these filters for use in the Embase.com platform, which is the platform you have access to at Hopkins.
Rarely, a review of observational studies will include a study filter. In these cases, check for validated filters before building your own.
Several organizations maintain lists of filters.
Note: If you choose to use one of the Qualitative Study filters for PubMed, you will need to update the MeSH term. As of December 2015, “questionnaires”[mesh] is now “surveys and questionnaires”[mesh].