Sun 2014.

Study characteristics
Methods	RCT
Participants	206 adults undergoing cholecystectomy in China
Interventions	Group 1: hair removal with a razor (n = 98) Group 2: no hair removal (n = 110) Product details: no details are given for the razor. Timing of hair removal: not reported. Hair removed by: trained nurses. Venue for hair removal: not reported.
Outcomes	Primary outcome: surgical site infection assessed using Ministry of Health definition. No further details given.
Notes	Published in Chinese. No details of conflict of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Participants were allocated using random number tables. Comment: method of generation of randomisation clear.
Allocation concealment (selection bias)	Unclear risk	No details provided. Comment: not clear whether the person responsible for allocation to groups would have been able to predict to which group a potential participant would be allocated.
Blinding (performance bias and detection bias) Care providers blinded	Unclear risk	Not reported. Comment: unclear whether care providers were blinded to intervention allocation.
Blinding (performance bias and detection bias) Participants blinded	High risk	Not reported. Comment: participants would have been aware if hair had been removed.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported. Comment: unclear whether assessors were blinded to intervention allocation.
Incomplete outcome data (attrition bias) ITT analysis undertaken	Unclear risk	Not reported. Comment: no discussion of whether participants were analysed in the groups to which they had been allocated.
Incomplete outcome data (attrition bias) Drop out rate acceptable	Unclear risk	Not reported. Comment: insufficient details to permit a judgement.
Selective reporting (reporting bias)	Low risk	Main outcomes reported. Comment: unlikely to be affected by reporting bias.
Other bias	Low risk	Comment: participant groups were equal or similar.