Study	Reason for exclusion
Agnifili 1993	Randomised trial evaluating laparoscopic and open cholecystectomy.
Al Tameem 1995	Prospective study on three different types of small‐incision cholecystectomy, not randomised.
Alexander 1997	Review on pain after laparoscopy; not a randomised trial.
Allen 2002	Comparison of costs of LC between ten surgeons; no comparison of operative procedures.
Alponat 2002	Randomised clinical trial on conventional LC (two 10 mm and two 5 mm ports) and LC by small instruments (one 10 mm and three 2 mm ports); thus comparison of two types of LC.
Anonymous 1995	Editorial: discussion of other article.
Assalia 1997	Randomised trial only including patients with acute cholecystitis.
Bablekos 2003	Correspondence with GD Bablekos on 11 October 2004: separating patients in triads with allocation according to registration sequence at the emergency ward: quasi‐randomised study of LC versus OC.
Barkun 1992	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Barkun 1993	Comparison of three different time periods; not a randomised trial.
Baxter 1992	Debate, consideration.
Bellon 1998	Randomised trial evaluating laparoscopic and open cholecystectomy.
Berggren 1994	Randomised trial evaluating laparoscopic and open cholecystectomy.
Bernard 1994	Economic evaluation.
Bigard 1995	Review on indications and methods of cholecystectomy in treatment of gallstones.
Blanc‐Louvry 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Blomstedt 1972	Study on the frequency of incisional hernias after different types of conventional cholecystectomy; not a randomised trial.
Bolke 2000	Quasi‐randomised trial: "... patients were randomised by alternate number to LC or OC ...".
Bruce 1999	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Bukan 2004	Randomised trial evaluating laparoscopic and open cholecystectomy.
Byrne 1994	Prospective, not randomised study: " ... equipment was only made available on an intermittent basis ...".
Calland 2001	Prospective study on outpatient LC, comparing with historical (inpatient) LC; not a randomised trial.
Caplan 1999	Study on costs and patient satisfaction before and after re‐engineering of a surgical service in LC patients and elective herniorrhaphy; no comparison of different types of cholecystectomy.
Champault 2002	One‐arm prospective study on costs; not a randomised trial (not two arms).
Charlo 1995	Randomised trial evaluating laparoscopic and open cholecystectomy.
Chaudhary 1999	Randomised trial evaluating laparoscopic and open cholecystectomy.
Chumillas 1998	Randomised trial evaluating laparoscopic and open cholecystectomy.
Clezy 1996	Letter.
Coelho 1992	Not a randomised trial; prospective study of small‐incision cholecystectomy.
Coskun 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Da Costa 1995	Prospective study, not randomised: "... patients were not randomised as it was felt that it was unethical to do so ...".
Dauleh 1995	Randomised trial evaluating laparoscopic and open cholecystectomy.
Decker 1993	Not randomised; prospective study.
Delogu 1999	Stress response in LC and OC patients, not randomised: "... 22 patients underwent OC and the other 24 had LC according to the availability of laparoscopic equipment ...".
Demirer 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Dionigi 1994	Randomised trial evaluating laparoscopic and open cholecystectomy.
Dohrmann 1993	Not randomised; randomisation was not possible as most patients opted for the laparoscopic technique.
Eickhoff 1997	Not a randomised trial: patients who were operated by LC or OC were analysed.
Engin 1998	Randomised trial evaluating laparoscopic and open cholecystectomy
Essen 1995	Randomised trial evaluating laparoscopic and open cholecystectomy.
Frazee 1991	No correct randomisation between two operative techniques: "... patients were randomly assigned to individual staff surgeons, as is our customary practice ...".
Gal 1997	Randomised trial evaluating laparoscopic and open cholecystectomy.
Galizia 2001	Randomised trial evaluating laparoscopic and open cholecystectomy.
GarciaCaballero 1993	Randomised trial evaluating laparoscopic and open cholecystectomy.
Glaser 1995	Prospective study with control group, not randomised: "... because of the ethical problems associated with randomisation of LC and OC, we decided to conduct a prospective trial without randomisation, but with a control group ...".
Go 1995	Retrospective study on cost‐effectiveness between extracorporeal shock‐wave lithotripsy, conventional cholecystectomy, and laparoscopic cholecystectomy.
Grande 2002	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Hagmuller 1997	Not randomised: the authors felt that randomisation was not possible on ethical grounds.
Hasukic 2002	Randomised trial evaluating laparoscopic and open cholecystectomy.
Hauer‐Jensen 1986	Randomised trial comparing performing cholecystectomy with or without a routine cholangiography.
Hendolin 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Hobbs 1995	Considerations on laparoscopic cholecystectomy, not a randomised trial.
Huang 1996	Randomised trial evaluating laparoscopic and open cholecystectomy.
Huguier 1997	Considerations on laparoscopic digestive surgery, not a randomised trial.
Hunter 2001	Editorial.
Iwase 1992	Not a randomised trial.
Jan 1993	Randomised trial evaluating laparoscopic and open cholecystectomy.
Johnson 1997	Considerations on laparoscopic surgery.
Johnson 1998	Personal view: consideration on efficacy, safety and training; not a randomised trial.
Johnson 1998a	Letter.
Karayiannakis 1997	Randomised trial evaluating laparoscopic and open cholecystectomy.
Karayiannakis 2002	Prospective study in patients having LC and OC, but no randomisation: "... twelve patients who had OC were recruited and served as the control group ...".
Kehlet 1993	Consideration of gallstone treatment modalities.
Keus 2006	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Kiviluoto 1997	Randomised trial between LC and OC on acute cholecystitis.
Kjaersgaard 1994	Randomised trial evaluating laparoscopic and open cholecystectomy.
Koprulu 1996	Randomised trial evaluating laparoscopic and open cholecystectomy.
Krasinski 1998	Prospective study on patients who underwent LC: patients with uncomplicated LC were compared to patients who had conversion from LC to OC.
Krawczyk 1993	Not a randomised trial: "the groups were not randomised".
Kunz 1992	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Kurzawinski 1992	Prospective study, but not randomised: "... patients were randomly allocated to either LC or OC, based on the availability of laparoscopic equipment ...".
Lam 1996	Survey in Scotland on cholecystectomy rate; not a randomised trial.
Lausten 1999 (1)	Randomised trial evaluating laparoscopic and open cholecystectomy.
Lausten 1999 (2)	Randomised trial evaluating laparoscopic and open cholecystectomy.
Lujan 1998	Randomised trial evaluating laparoscopic and open cholecystectomy.
Lukichev 1983	Cohort of patients treated by one technique; not a randomised trial.
Luo 2003	Randomised trial evaluating laparoscopic and open cholecystectomy.
Majeed 1996	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Makinen 1995	Only pilot phase of trial; in pilot phase no randomisation: SIC was performed when LC instruments were not available.
Malaysian HTA 2005	Systematic review on different types of minimal access surgery; not a randomised trial.
Maruszynski 1995	Patients with acute cholecystitis only.
Matsunaga 1996	Comparison of two different types of anaesthesia in cholecystectomy.
McGinn 1995	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
McKellar 1995	Comparison of historical cohorts.
McMahon 1994	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
McMahon 1996	Letter, not a randomised trial.
Mealy 1992	An unselected group of patients undergoing LC in one hospital was compared with a group undergoing OC in another hospital.
Milheiro 1994	Randomised trial evaluating laparoscopic and open cholecystectomy.
Mimica 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Mrksic 2001	No randomisation.
Novitsky 2002	Randomised controlled trial on two types of laparoscopic cholecystectomy (mini‐port LC (2 mm) versus conventional LC).
Ogawa 2001	Retrospective study on LC versus OC in patients with cardiac valve replacement.
Olsen 1993	Review of literature from 1970 to 1992 on mini‐lap cholecystectomy: only articles in English were included and data on conventional and laparoscopic cholecystectomy were obtained from large series reported in literature.
Ortega 1996	Randomised trial evaluating laparoscopic and open cholecystectomy.
Plaisier 1995	Prospective not randomised study: "... allocation to either laparoscopic or conventional cholecystectomy depended on the availability of a laparoscopic set ...".
Prisco 2000	Randomised trial evaluating laparoscopic and open cholecystectomy.
Putensen‐Himmer 1992	Randomised trial evaluating laparoscopic and open cholecystectomy.
Rademaker 1992	Patients underwent conventional subcostal cholecystectomy whenever the instrumentation for laparoscopic surgery was not available; the laparoscopic group had on alternating basis general anaesthesia combined with epidural analgesia or general anaesthesia alone; not randomised.
Redmond 1994	Study evaluating laparoscopic and small‐incision cholecystectomy.
Rhodes 1996	Not a randomised trial; comment on other article.
Romana 2000	Not randomised: "patients were divided into two groups".
Ros 2001	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Rovina 1996	Randomised trial evaluating laparoscopic and open cholecystectomy.
Schauer 1993	No correct randomisation of surgical techniques: ".. patients were randomly assigned to one of four general surgical services; two of these used only the open cholecystectomy technique, and the other two used the laparoscopic approach ..".
Schauer 1995	Not randomised; ".. procedure was determined by the attending physician ..".
Schaupp 1988	Randomised clinical trial on two types of conventional cholecystectomy (with nasogastric tube, iv infusion and subhepatic drain versus no tube, no infusion and no drain).
Secco 2002	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Srivastava 2001	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Tate 1993	Randomised trial evaluating laparoscopic and small‐incision cholecystectomy.
Thaler 1995	Trial on LC and OC patients, but no randomisation as the authors found that laparoscopic cholecystectomy was the method of first choice.
Toouli 1998	Review on gallstones; not a randomised trial.
Trondsen 1993	Randomised trial evaluating laparoscopic and open cholecystectomy.
Ueo 1994	Prospective comparison between IL‐6 levels in LC and OC patients, but not randomised: " ... patients who underwent cholecystectomy, 12 each for OC and LC, were chosen as subjects in this study ...".
Volpino 1998	Randomised trial evaluating laparoscopic and open cholecystectomy.
Williams 1993	Prospective study on LC and OC pulmonary function, but not randomised: "... selection for OC or LC depended upon surgeon ...".
Yerdel 1997	Prospective study in cirrhotic patients on laparoscopic versus open cholecystectomy; not randomised ( "... all cirrhotic patients were offered LC ..." ).
Zajac 1998	Randomised trial evaluating laparoscopic and open cholecystectomy.
Zulfikaroglu 2002	Randomised trial evaluating laparoscopic and open cholecystectomy.

LC: laparoscopic cholecystectomy; 
 OC: open cholecystectomy.