Seenu 1994.

Methods	Single‐centre randomised trial, operations performed by consultants and senior residents. Generation of allocation: unclear. Allocation concealment: unclear. Blinding: not performed. Follow‐up: unclear. Drop‐outs: none mentioned. Intention‐to‐treat: not mentioned. Sample size calculations: no.
Participants	Patients undergoing elective cholecystectomy. In‐ and exclusion criteria: not very well described. Comparability groups: not very well described.
Interventions	SIC versus OC. SIC: very well described, a 5 cm transverse incision in the right upper quadrant. OC: vertical midline incision. Antibiotic prophylaxis: not mentioned. Intra‐operative cholangiography: no, selective pre‐operative cholangiogram was performed when necessary.
Outcomes	Primary and secondary outcome: not mentioned. Outcome measures: complications, operative time, hospital stay. Duration of follow‐up: 30 days.
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Allocation concealment?	Unclear risk	B ‐ Unclear
Blinding? All outcomes	High risk
Free of selective reporting?	High risk