Database	Search date	Database date range/issue/version	Number of records
Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library	21 August 2014	July 2014 (Issue 7)	506
	20 April 2016	April 2016 (Issue 4)	77
	5 April 2017	March 2017 (Issue 3)	36
Ovid MEDLINE	20 August 2014	1946 to August Week 1 2014	1740
	18 April 2016	1946 to April Week 1 2016	221
	4 April 2017	1946 to March Week 4 2017	116
Ovid MEDLINE Epub Ahead of Print	4 April 2017	3 April 2017	49
Ovid MEDLINE In‐Process & Other Non‐Indexed Citations	4 April 2017	3 April 2017	143
Embase (Ovid)	20 August 2014	1980 to 2014 Week 33	1508
	18 April 2016	1980 to 2016 Week 16	298
	4 April 2017	1974 to 2017 Week 14	208
ERIC ProQuest (Education Resources Information Center)	20 August 2014	1966 to current	1047
	20 April 2016	1966 to current	62
	5 April 2017	1966 to current	73
CINAHL Plus EBSCOhost (Cumulative Index to Nursing and Allied Health Literature)	21 August 2014	1937 to current	604
	18 April 2016	1937 to current	66
	4 April 2017	1937 to current	54
PsycINFO (Ovid)	20 August 2014	1806 to August Week 2 2014	359
	18 April 2016	1806 to April Week 2 2016	68
	4 April 2017	1806 to April Week 2 2017	31
Science Citation Index ‐ Expanded and Social Sciences Citation Index Web of Science (SCI‐Expanded; SSCI, respectively)	22 August 2014	1970 to 21 August 2014	1306
	20 April 2016	1970 to 18 April 2016	342
	4 April 2017	1970 to 31 March 2017	156
Conference Proceedings Citation Index ‐ Science and Conference Proceedings Citation Index ‐ Social Science & Humanities Web of Science (CPCI‐S; CPCI‐SS&H, respectively)	22 August 2014	1990 to 21 August 2014	112
	20 April 2016	1990 to 18 April 2016	5
	4 April 2017	1990 to 31 March 2017	1
Cochrane Database of Systematic Reviews (CDSR) in the Cochrane Library	21 August 2014	August 2014 (Issue 8 of 12)	10
	20 April 2016	April 2016 (Issue 4 of 12)	7
	5 April 2017	April 2017 (Issue 4 of 12)	2
Database of Reviews of Abstracts of Effects (DARE) in the Cochrane Library	21 August 2014	July 2014 (Issue 3 of 4)	14
	20 April 2016	April 2015 (Issue 2 of 4)	0
ProQuest Dissertations & Theses: UK & Ireland	22 August 2014	Current issue	49
	20 April 2016	Current issue	4
	5 April 2017	Current issue	0
WorldCat (worldcat.org)	22 August 2014	Current issue	36
	20 April 2016	Current issue	7
	4 April 2017	Current issue	0
ClinicalTrials.gov (clinicaltrials.gov)	18 June 2015	Current issue	9
	22 April 2016	After 6 January 2015	16
	31 March 2017	Current issue	20
metaRegister of Controlled Trials (mRCT; www.controlled‐trials.com) This service was under review in 2016 and 2017.	18 June 2015	Current issue	1
ISRCTN registry (www.isrctn.com)	22 April 2016	Current issue	8
	31 March 2017	Current issue	6
World Health Organization International Clinical Trials Registry Platform (WHO ICTRP; apps.who.int/trialsearch)	18 June 2015	Current issue	12
	22 April 2016	Current issue	6
	31 March 2017	Current issue	18
Australian New Zealand Clinical Trials Registry (ANZCTR; anzctr.org.au/trialSearch.aspx)	18 June 2015	Current issue	2
	22 April 2016	Current issue	4
	31 March 2017	Current issue	4