Cuschieri 1999.

Methods	Multicentre randomised trial comparing pre‐operative ERC/ES and stone extraction followed by LC versus LC +/‐ laparoscopic stone extraction. Adequate report of protocol violations and drop‐outs. Sample size calculations: yes.
Participants	International trial based in Dundee. UK. Study commenced 1994, completed August 1997. 300 pts randomised. Inclusion criteria: ASA I or II. Ductal stones proven or suspected on clinical (jaundice, recent pancreatitis), biochemical (raised LFTs), or US findings. Essential investigations: LFTs, US. Optional investigations: IVC, CT.
Interventions	Group 1: 136/150 received correct treatment: Pre‐operative ERCP +/‐ ES and stone extraction when found. Subsequent laparoscopic cholecystectomy. IOC left to discretion of surgeon. Group 2: 133/150 received correct treatment: Laparoscopic cholecystectomy. IOC in all cases. Laparoscopic stone extraction attempted when stones found.
Outcomes	Mortality, morbidity, hospital stay.
Notes	10% protocol violations. Pts in Group 1 could have had more than one pre‐operative attempt at ERCP. In Group 2 conversions to open surgery treated as successful clearance. Transcystic CBDE was performed for small non‐occluding stones and transcholedochal CBDE was performed for large or occluding stones.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation was by a random number generator.
Allocation concealment (selection bias)	Unclear risk	Trial was described as randomised, but the method used to conceal the allocation was not described.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible.
Selective reporting (reporting bias)	Low risk	All outcomes were clearly defined and reported.
Incomplete outcome data	Low risk	No missing data.
For‐profit bias	Low risk	Appears free of for‐profit support.
Other bias	Low risk	None.