Rojanapirom 1992.

Study characteristics
Methods	RCT
Participants	80 acute patients (from 12 years of age) undergoing appendicectomy in Thailand between May and August 1988
Interventions	Group 1: hair removal with a razor (n = 40) Group 2: no hair removal (n = 40) Product details: skin was shaved with a razor on the ward following a scrub with antiseptic solution by hospital staff. Timing of hair removal: not reported. Hair removed by: not reported. Venue for hair removal: not reported.
Outcomes	Primary outcome: wound infection. Wounds were examined on days 2 and 3 postoperatively and until the stitches were removed (days 7 to 10). Definition of an infection and details of who assessed the wound not provided. Wound swabs were also taken intraoperatively.
Notes	No details of any funding. No details of conflict of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "Each pair was randomly divided into control (shaved skin) and experiment (unshaved skin) groups." Comment: process of randomisation not given.
Allocation concealment (selection bias)	Unclear risk	Not reported. 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	Quote: "Skin preparation in the control group. . . skin shaving with a razor. In the experiment group skin shaving was omitted." Comment: participants would have been aware of hair removal method.
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.