Randomized Controlled Trials and Other Trials: Filters
Inclusion of a search filter on this site is not an endorsement of its validity or a recommendation for its use by the editors of this site, by the InterTASC Information Specialists SubGroup or by the (UK) National Institute for Health and Care Excellence (NICE). For suggestions on the appraisal of filters see the ISSG Search Filter Appraisal Checklist.
This page shows publications that have reviewed search filter performance and individual search filters.
Please note that other filter sites/filter collections may have relevant filters for this topic.
Publications that review search filter performance
Glanville J, Kotas E, Featherstone R, Dooley G. Which are the most sensitive search filters to identify randomized controlled trials in MEDLINE? J Med Libr Assoc. 2020 Oct 1;108(4):556-563. doi: 10.5195/jmla.2020.912. PMID: 33013212; PMCID: PMC7524635.
Also a conference abstract presented at HTAi 2020
Cooper C, Varley-Campbell J, Carter P. Established search filters may miss studies when identifying randomized controlled trials. J Clin Epidemiol. 2019 Apr 13;112:12-19. doi: 10.1016/j.jclinepi.2019.04.002. [Epub ahead of print]
Note: there is correspondence on this paper and the authors' reply - links here.
Sperr, E V. Mind the gap: identifying what is missed when searching only the broad scope with clinical queries. J Med Libr Assoc 2019;107(3):333–340.
Gorayeb RP, Forjaz MJ, Ferreira AG, Duarte GNS, Machado T, Ferreira JJ. Electronic search strategies fail to identify randomized controlled trials (RCTs) in neurosurgery. Clin Neurol Neurosurg. 2019;184:105446. [this reviews the performance of one filter in neurosurgery]
O'Rourke JM, Ward KE, Thompson JC Single-arm trials in systematic reviews: are they adequately captured by existing search filters? ISPOR 19th Annual European Congress Vienna, Austria October, 2016
Durão S, Kredo T, Volmink J. Validation of a search strategy to identify nutrition trials in PubMed using the relative recall method. J Clin Epidemiol. 2015;68(6):610-6
Lokker C, Haynes RB, Wilczynski NL, McKibbon KA, Walter SD. Retrieval of diagnostic and treatment studies for clinical use through PubMed and PubMed's Clinical Queries filters. J Am Medi Inform Assoc. 2011;18(5):652-9. Epub 2011 Jun 15.
Yousefi-Nooraie R, Irani S, Mortaz-Hedjri S, Shakiba B. Comparison of the efficacy of three PubMed search filters in finding randomized controlled trials to answer clinical questions J Eval Clin Pract. 2013;19(5):723-6. doi: 10.1111/j.1365-2753.2010.01554.x. Epub 2010 Sep 16.
Hoogendam A, de Vries Robbé P F, Stalenhoef A F H, Overbeke J P M. Evaluation of PubMed filters used for evidence-based searching: validation using relative recall. J Med Libr Assoc. 2009; 97(3): 186-193. doi: 10.3163/1536-5050.97.3.007.
McKibbon KA, Wilczynski N L, Haynes R B. Retrieving randomized controlled trials from medline: a comparison of 38 published search filters. Health Info Libr J. 2009; 26(3):187-202.
Bardia A, Wahner-Roedler DL, Erwin PL, Sood A. Search strategies for retrieving complementary and alternative medicine clinical trials in oncology. Integr Cancer Ther. 2006;5(3):202-5
Anthony D, Hill S, Johnson K, Stokes B. A better gold pan: capturing RCTs with more precision. 13th Cochrane Colloquium; 2005 October 22-26; Melbourne, Australia.
Sampson M, Zhang L, Ajiferuke I, Sampson M. Optimizing search strategies to identify randomized controlled trials in MEDLINE. 12th Cochrane Colloquium; 2004 October 2-6; Ottawa, Canada.
Individual search filters
Database indexing changes over time and new vocabulary may be introduced. With older filters, please check the subject indexing to ensure that the subject indexing is still current and, if not, consider whether new vocabulary may need to be added to the filter. Please note that if filters are amended, the performance may change from that published in the original articles and the filter should be reported as amended from the original filter.
CINAHL
CADTH sensitive search filter for all clinical trials in CINAHL [EBSCO]. Last updated 24 March 2022.
Glanville Julie, Dooley Gordon, Wisniewski Susi, Foxlee Ruth, Noel‐Storr Anna. Development of a search filter to identify reports of controlled clinical trials within CINAHL Plus. Health Lib J. 2019;36:73-90
Please note that line 1 of this filter should now be replaced with MH randomized controlled trials+, reflecting the NLM introduction of more specific terms below the heading (May 2023)
SIGN search filter [undated] [Ovid]
Wong SS, Wilczynski NL, Haynes RB. Optimal CINAHL search strategies for identifying therapy studies and review articles. J Nurs Scholarsh. 2006;38(2):194-9.
Embase
VonVille, Helena. Filter for controlled trials. [Embase.com]
Avau B, Van Remoortel H, De Buck E. Translation and validation of PubMed and Embase search filters for identification of systematic reviews, intervention studies, and observational studies in the field of first aid. J Med Libr Assoc. 2021;109(4):599-608. [Embase.com]
CADTH search filter for all clinical trials using a multifile Ovid search in MEDLINE, Embase and PsycINFO [Ovid]. Last updated 16 December 2021.
Glanville J, Foxlee R, Wisniewski S, Noel-Storr A, Edwards M, Dooley G. Translating the Cochrane EMBASE RCT filter from the Ovid interface to Embase.com: a case study. Health Info Libr J. 2019 Jul 22. doi: 10.1111/hir.12269
The filter has been revised in April 2023. A version of the filter for searchers using Ovid and Embase.com is available here.
Embase Ovid strategy (April 2023) search launch
Wong SS, Wilczynski NL, Haynes RB. Developing optimal search strategies for detecting clinically sound treatment studies in EMBASE. J Med Libr Assoc. 2006;94(1):41-7. [Ovid]
Chow TKF, To, E, Goodchild CS, McNeil, JJ A simple, fast, easy method to identify the evidence base pain-relief research. Validation of a computer search strategy used alone to identify quality randomized controlled trials. Anesth Analg 2004; 98(6):1557-1565. [Ovid]
Galandi D, Bassler D, Antes G. Identifying randomized controlled trials published in German general health care journals using Medline and Embase: how useful is the controlled vocabulary? [abstract] 8th Cochrane Colloquium; 2000 October 25-29; Cape Town, South Africa.
Watson RJ, Richardson PH. Identifying randomized controlled trials of cognitive therapy for depression: comparing the efficiency of Embase, Medline and PsycINFO bibliographic databases. Br J Med Psychol. 1999;72(4):535-42. [RCTs of cognitive therapy for depression] [Ovid]
Burdett S, Stewart LA, Tierney JF. Searching bibliographic databases: costs and benefits [abstract]. 2nd International Conference. Scientific Basis of Health Services & 5th Cochrane Colloquium; October 1997; Amsterdam, The Netherlands.
BMJ Clinical Evidence strategy [undated] [Ovid]
OVID Randomised controlled trials search filter [undated]
SIGN search filter [undated] [Ovid]
LILACS
Manríquez JJ. A highly sensitive search strategy for clinical trials in Literatura Latino Americana e do Caribe em Ciências da Saúde (LILACS) was developed. J Clin Epidemiol. 2008;61(4):407-11.
de Freitas AE, Herbert RD, Latimer J, Ferreira PH. Searching the LILACS database for Portuguese- and Spanish-language randomized trials in physiotherapy was difficult. J Clin Epidemiol. 2005;58(3):233-7. [RCTs in physiotherapy]
Castro AA, Clark OA, Atallah AN. Optimal search strategy for clinical trials in the Latin American and Caribbean Health Science Literature database (LILACS database): update. Sao Paulo Med J. 1999;117(3):138-9.
MEDLINE
Cochrane RCT filters. Lefebvre C, Glanville J, Briscoe S, Featherstone R, Littlewood A, Metzendorf M-I, Noel-Storr A, Paynter R, Rader T, Thomas J, Wieland LS. Chapter 4: Searching for and selecting studies. In: Higgins JPT, Thomas J, Chandler J, Cumpston M, Li T, Page MJ, Welch VA (editors). Cochrane Handbook for Systematic Reviews of Interventions version 6.4 (updated October 2023). Cochrane, 2023. Available from www.training.cochrane.org/handbook [Ovid, PubMed]
2023 update: The MeSH 'Randomized controlled trial' now has more specific headings, so the Ovid version of the filter has been edited to explode that subject heading
Launch Cochrane RCT sensitivity maximising filter (2023 revision) for PubMed
Launch Cochrane RCT sensitivity and precision maximising filter (2023 revision) for PubMed
Launch MEDLINE Sensitivity-maximizing version (2023 revision) for Ovid (subscribers only)
Launch MEDLINE Sensitivity- and precision-maximizing version (2023 revision) for Ovid (subscribers only)
VonVille, Helena. Filters for controlled trials
Avau B, Van Remoortel H, De Buck E. Translation and validation of PubMed and Embase search filters for identification of systematic reviews, intervention studies, and observational studies in the field of first aid. J Med Libr Assoc. 2021;109(4):599-608. [PubMed]
CADTH search filter for all clinical trials using a multifile Ovid search in MEDLINE, Embase and PsycINFO [Ovid]. Last updated 16 December 2021.
Taljaard M, McDonald S, Nicholls SG, et al. A search filter to identify pragmatic trials in MEDLINE was highly specific but lacked sensitivity. J Clin Epidemiol. 2020; 124: 75-84.
Corrao S, Colomba D, Argano C, Calvo L, Scaglione R, et al. Optimized search strategy for detecting scientifically strong studies on treatment through PubMed. Intern Emerg Med. 2012;7(3):283-287
Taljaard M, McGowan J, Grimshaw JM, Brehaut JC, McRae A, Eccles MP, Donner A: Electronic search strategies to identify reports of cluster randomized trials in MEDLINE: low precision will improve with adherence to reporting standards. BMC Med Res Methodol. 2010;10:15
Eisinga A, Siegfried N, Clarke M. The sensitivity and precision of search terms in phases I, II and III of the Cochrane Highly Sensitive Search Strategy for identifying reports of randomized trials in MEDLINE in a specific area of health care- HIV/AIDS prevention and treatment interventions. Health Info Libr J. 2007;24(2):103-09. [RCT and CCTs in HIV/AIDS interventions] [PubMed]
Royle PL, Waugh NR. Making literature searches easier: a rapid and sensitive search filter for retrieving randomized controlled trials from PubMed. Diabet Med. 2007;24(3):308-11 [PubMed]
Corrao S, Colomba D, Arnone S, Argano C, Di Chiara T, Scaglione R, Licata G. Improving efficacy of PubMed clinical queries for retrieving scientifically strong studies on treatment. J Am Med Inform Assoc. 2006;13:485-7. [PubMed]
Comment: Wilczynski, N. L. and R. B. Haynes Response to Corrao et al.: Improving efficacy of PubMed clinical queries for retrieving scientifically strong studies on treatment. J Am Med Inform Assoc 2007;14(2): 247-248.
Glanville JM, Lefebvre C, Miles JN, Camosso-Stefinovic J. How to identify randomized controlled trials in MEDLINE: ten years on. J Med Libr Assoc. 2006;94(2):130-6. Erratum: J Med Libr Assoc. 2006;94(3):354.
Comment: Wilczynski, N. L., et al. Response to Glanville et al.: How to identify randomized controlled trials in MEDLINE: ten years on. J Med Libr Assoc 2007;95(2): 117-118; author reply 119-120.
Comment: Leclercq, E. Response to Glanville et al. J Med Libr Assoc 2007;95(2): 118-119; author reply 119-120.
Zhang L, Ajiferuke I, Sampson M. Optimizing search strategies to identify randomized controlled trials in MEDLINE. BMC Med Res Methodol. 2006;6:23. [Ovid]
Haynes RB, McKibbon KA, Wilczynski NL, Walter SD, Werre SR, Hedges Team. Optimal search strategies for retrieving scientifically strong studies of treatment from Medline: analytical survey. BMJ 2005;330(7501):1179. [PubMed]
Royle P, Waugh N. A simplified search strategy for identifying randomised controlled trials for systematic reviews of health care interventions: a comparison with more exhaustive strategies. BMC Med Res Methodol. 2005;5:23. [Ovid]
Chow TKF, To, E, Goodchild CS, McNeil, JJ A simple, fast, easy method to identify the evidence base pain-relief research. Validation of a computer search strategy used alone to identify quality randomized controlled trials. Anesth Analg 2004; 98(6):1557-1565. {Ovid]
Chow T, To E, Goodchild C, McNeil J. Improved indexing of randomised controlled trials has enabled computer search strategies to identify them with high sensitivity and specificity, in pain relief research [abstract]. 8th Cochrane Colloquium; 2000 October 25-29; Cape Town, South Africa. [Ovid]
Heran B S, Wright J M. Development of an optimal search strategy for finding trials demonstrating ACE inhibitor blood pressure lowering efficacy [poster]. 10th Cochrane Colloquium; 2002 July 31 - August 3; Stavanger, Norway. [RCTs in hypertension treatment] [Ovid]
Robinson KA, Dickersin K. Development of a highly sensitive search strategy for the retrieval of reports of controlled trials using PubMed. Int J Epidemiol. 2002; 31(1):150-3. [Controlled trials] [PubMed]
Dumbrigue HB, Esquivel JF, Jones JS. Assessment of MEDLINE search strategies for randomized controlled trials in prosthodontics. J Prosthodont. 2000;9(1):8-13. [RCTs in prosthodontics]
Galandi D, Bassler D, Antes G. Identifying randomized controlled trials published in German general health care journals using Medline and Embase: how useful is the controlled vocabulary? [abstract] 8th International Cochrane Colloquium; 2000 October 25-29; Cape Town, South Africa.
Watson RJ, Richardson PH. Identifying randomized controlled trials of cognitive therapy for depression: comparing the efficiency of Embase, Medline and PsycINFO bibliographic databases. Br J Med Psychol. 1999;72(4):535-42. [RCTs of cognitive therapy for depression] [Ovid]
Brand M, Gonzalez J, Aguilar C. Identifying RCTs in MEDLINE by publication type and through the Cochrane Strategy: the case in hypertension [abstract]. 6th Annual Cochrane Colloquium; October 1998; Baltimore, USA. [RCTs in hypertension]
Bender JS, Halpern SH, Thangaroopan M, Jadad AR, Ohlsson A. Quality and retrieval of obstetrical anaesthesia randomized controlled trials. Can J Anaesth. 1997; 44(1):14-8. [RCTs in obstetrical anaesthesia]
Burdett S, Stewart LA, Tierney JF. Searching bibliographic databases: costs and benefits [abstract]. 2nd International Conference. Scientific Basis of Health Services & 5th Annual Cochrane Colloquium; October 1997; Amsterdam, The Netherlands.
Duggan LM, Morris M, Adams CE. Prevalence study of the randomized controlled trials in the Journal of Intellectual Disability Research: 1957-1994. J Intellect Disabil Res. 1997;41(3):232-237. [SilverPlatter]
McDonald S, Clarke M, Lefebvre C. Should we continue to handsearch MEDLINE-indexed journals prospectively? Some up-to-date empirical evidence [abstract]. 2nd International Conference. Scientific Basis of Health Services & 5th Cochrane Colloquium; October 1997; Amsterdam, The Netherlands.
Marson A G, Chadwick D W. How easy are randomized controlled trials in epilepsy to find on Medline? The sensitivity and precision of two Medline searches. Epilepsia 1996;37(4):377-380. [RCTs in epilepsy] [SilverPlatter]
Adams CE, Power A, Frederick K, Lefebvre C. An investigation of the adequacy of MEDLINE searches for randomized controlled trials (RCTs) of the effects of mental health care. Psychol Med. 1994; 24(3):741-8.
Dickersin K, Scherer R, Lefebvre C. Identifying relevant studies for systematic reviews. BMJ 1994;309(6964):1286-91.
Haynes R, Wilczynski N, McKibbon K, Walker C, Sinclair J. Developing optimal search strategies for detecting clinically sound studies in MEDLINE. J Am Med Inform Assoc. 1994;1:447-458. [Treatment including RCTs]
Sperr, E V. Mind the gap: identifying what is missed when searching only the broad scope with clinical queries. J Med Libr Assoc 2019;107(3):333–340.
Solomon MJ, Laxamana A, Devore L, McLeod RS. Randomized controlled trials in surgery. Surgery 1994;115(6):707-12. [RCTs in surgery]
Jadad AR, McQuay HJ. A high-yield strategy to identify randomized controlled trials for systematic reviews. Online J Curr Clin Trials. 1993 Feb 27;Doc No 33
Gøtzsche PC, Lange B. Comparison of search strategies for recalling double-blind trials from MEDLINE. Dan Med Bull 1991;38:476-8. [Double-blind trials]
Kirpalani H, Schmidt B, McKibbon KA, Haynes RB, Sinclair J C. Searching MEDLINE for randomized clinical trials involving care of the newborn. Pediatrics 1989;83(4):543-546. [RCTs in care of the newborn] [Grateful Med]
Bernstein F. The retrieval of randomized clinical trials in liver diseases from the medical literature: manual versus MEDLARS searches. Control Clin Trials 1988; 9(1):23-31. [RCTs in liver diseases] [MEDLARS]
Dickersin K, Hewitt P, Mutch L, Chalmers I, Chalmers TC. Perusing the literature: comparison of MEDLINE searching with a perinatal trials database. Control Clin Trials 1985;6(4):306-17.
Poynard T, Conn HO. The retrieval of randomized clinical trials in liver disease from the medical literature. A comparison of MEDLARS and manual methods. Control Clin Trials 1985;6(4):271-9. [RCTs in liver diseases] [MEDLARS]
BMJ Clinical Evidence strategy [undated] [Ovid]
OVID Randomised controlled trials search filter [undated]
SIGN search filter [undated] [Ovid]
PsycINFO
CADTH search filter for all clinical trials using a multifile Ovid search in MEDLINE, Embase and PsycINFO [Ovid]. Last updated 16 December 2021.
Randomized Controlled Trials / Controlled Clinical Trials: A Cut and Paste Search Strategy adapted from CADTH for Ovid PsycINFO. Adapted from: “Canadian Agency for Drugs and Technology in Health [Internet]. Strings attached: CADTH’s database search filters - randomized controlled trials / controlled clinical trials — OVID Medline, Embase, PsycINFO. Ottawa: CADTH; 2018.” Geoffrey & Robyn Sperber Health Sciences Library, University of Alberta. Rev. December 9, 2020.
Eady AM, Wilczynski NL, Haynes RB. PsycINFO search strategies identified methodologically sound therapy studies and review articles for use by clinicians and researchers. J Clin Epidemiol. 2008;61(1):34-40. [Ovid]
Watson RJ, Richardson PH. Identifying randomized controlled trials of cognitive therapy for depression: comparing the efficiency of Embase, Medline and PsycINFO bibliographic databases. Br J Med Psychol. 1999;72(4):535-42. [RCTs of cognitive therapy for depression] [Ovid]
Duggan LM, Morris M, Adams CE. Prevalence study of the randomized controlled trials in the Journal of Intellectual Disability Research: 1957-1994. J Intellect Disabil Res. 1997;41(3):232-7. [SilverPlatter]
Scopus
CADTH search filter for all clinical trials. Last updated 20 December 2021.
Dennett, Liz. Randomized Controlled Trials / Controlled Clinical Trials: A Cut and Paste Search Strategy for Scopus. Adapted from “Glanville JM, Lefebvre C, Miles JN, Camosso-Stefinovic J. How to identify randomized controlled trials in MEDLINE: ten years on. Journal of the Medical Library Association 2006; 94: 130-136”. Geoffrey & Robyn Sperber Health Sciences Library, University of Alberta. Rev. December 9, 2020.
Web of Science
Tjosvold, L. Randomized Controlled Trials / Controlled Clinical Trials: A Cut and Paste Search Strategy adapted from the Cochrane ENT Group for Web of Science. Adapted from “RCT Filters used by Cochrane ENT. Oxford (UK): Cochrane ENT Group; 2018.” Geoffrey & Robyn Sperber Health Sciences Library, University of Alberta. Rev. February 2, 2024.