Suvera 2013.

Study characteristics
Methods	RCT
Participants	215 adults having general surgery in India between April 2010 and March 2012
Interventions	Group 1: hair removal with a razor (112 participants) Group 2: hair removal with depilatory cream (103 participants) Product details: no details are given for the razor, the cream consisted of potassium thioglycolate. Timing of hair removal: on the day of operation. Hair removed by: nursing staff. Venue for hair removal: not reported.
Outcomes	Primary outcome: adequacy of method, skin trauma. Skin was assessed preoperatively by a surgical resident and postoperatively by a senior resident on days 3, 5, and 7. Secondary outcome: SSIs were recorded using a "modification of the Southampton scoring system". All participants were followed up for at least 6 weeks. No further details provided.
Notes	Sources of support: none. Conflict of interest: none declared.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "consecutive patients were asked to pick one of two sealed envelopes ... on which one of the two methods was written" Comment: randomised.
Allocation concealment (selection bias)	Low risk	Quote: "consecutive patients were asked to pick one of two sealed envelopes containing a folded paper on which one of the two methods was written" Comment: allocation concealed.
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	Staff who assessed wounds did not participate in the surgery and were unaware of participants' group allocation status. Comment: outcome assessors were blinded.
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	Participants who dropped out are accounted for, and participants are distributed evenly across groups. Comment: the number of dropouts was judged to be unlikely to have altered the result, even in a worst‐case scenario (i.e. assuming that those that dropped out developed an SSI).
Selective reporting (reporting bias)	Low risk	Main outcomes reported. Comment: unlikely to be affected by reporting bias.
Other bias	Unclear risk	Comment: no information on the similarity of groups.