Database	Timespan of search	Search strategy	Hits	Titles selected
The Cochrane Hepato‐Biliary Group Controlled Trials Register	6 April 2004	"cholelithiasis OR gallstones OR cholecystectomy"	843	65
Cochrane Database of Systematic Reviews in The Cochrane Library	Issue 1, 2004	"cholecystectomy"	33	0
Database of Abstracts of Reviews of Effects in The Cochrane Library	Issue 1, 2004	"cholecystectomy"	17	5
Cochrane Central Register of Controlled Trials in The Cochrane Library	Issue 1, 2004	"cholecystectomy"	1343	146
Health Technology Assessment Database in The Cochrane Library	Issue 1, 2004	"cholecystectomy"	11	4
NHS Economic Evaluation Database in The Cochrane Library	Issue 1, 2004	"cholecystectomy"	43	6
MEDLINE	1950 to January 2004	(((Gallbladder[Tiab] AND (Surgery[Tiab] OR Endoscopy[Tiab] OR Surgical[Tiab] OR Laparoscopy[Tiab])) OR Cholecystectomy[Tiab]) OR ((("Gallbladder"[MeSH] OR "Gallbladder Diseases"[MeSH]) AND ("Surgery"[MeSH] OR "surgery"[Subheading] OR "Endoscopy, Gastrointestinal"[MeSH] OR "Surgical Procedures, Operative"[MeSH] OR "Surgical Procedures, Minor"[MeSH] OR "Laparoscopy"[MeSH])) OR "Cholecystectomy"[MeSH])) AND (randomized controlled trial[PTYP] OR randomized controlled trials OR controlled clinical trial[PTYP] OR clinical trial[PTYP] OR clinical trials OR (clinical AND trial) OR random allocation OR random* OR double blind method OR single blind method OR (singl* OR doubl* OR trebl* OR tripl*) OR blind* OR mask* OR placebo* OR placebos OR research design OR comparative study OR evaluation studies OR follow up studies OR prospective studies OR control OR controlled OR prospectiv* OR volunteer*)	8354	347
EMBASE	1966 to January 2004	"cholecystectomy"	685	131
Web of Science	1988 to January 2004	TS=(cholecystectomy AND random*)	1163	148
CINAHL	1982 to January 2004	"cholecystectomy"	740	9
Total			13232	586