Lu 2002.

Study characteristics
Methods	QRCT
Participants	60 people (from 6 years of age) having elective thoracic surgery in China between August and December 2001
Interventions	Group 1: hair removal with clipper (n = 30) Group 2: no hair removal (n = 30) Product details: no details are given for the clipper. Timing of hair removal: the morning of the day before surgery. Hair removed by: not reported. Venue for hair removal: not reported.
Outcomes	Primary outcome: skin bacterial culture taken on the operating table prior to skin preparation and 16 hours after surgery. Secondary outcome: surgical site infection. Assessed by a trained person. Definition of infection or time when assessed not provided.
Notes	No funding sources mentioned. No details of conflict of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	High risk	Randomisation by odd and even numbers. Comment: inadequate randomisation technique.
Allocation concealment (selection bias)	High risk	Randomisation by odd and even numbers. Comment: care provider could predict allocation by reference to hospital number.
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 of hair removal method.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessment used a "double blind method". Comment: achieved.
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	Low risk	No participants appeared to have dropped out from the study. Comment: unclear whether participants failed to complete.
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.