Sureshkumar 2018.

Study characteristics
Methods	Design: parallel‐group RCT Study period: not reported
Participants	Setting: elective general or colorectal surgery Type of stoma: ileostomy or colostomy Inclusion criteria Age ≥ 12 years Exclusion criteria Unwillingness to participate
Interventions	PSSC using subcuticular absorbable suture (n = 40) versus LSC using interrupted non‐absorbable suture (n = 40). No mesh or drain was used during closure in either group.
Outcomes	SSI within 30 days of operation according to CDC criteria Participant satisfaction (Likert 5‐point scale) at 3 months' follow‐up Incisional hernia Anastomotic leak Operative time Length of hospital stay
Notes	The 2 groups were comparable in terms of baseline characteristics. The length of follow‐up was 3 months. The study received no external funding, but it was unclear whether the protocol had been registered. The study authors declared no conflicts of interest.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Method and type of randomisation described appropriately.
Allocation concealment (selection bias)	Low risk	Method used for randomisation supports allocation concealment.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Participants and personnel were not blinded (blinding may not be practical in this setting).
Blinding of outcome assessment (detection bias) All outcomes	High risk	Outcome assessment was not blinded (blinding may not be practical in this setting).
Incomplete outcome data (attrition bias) All outcomes	Low risk	Complete outcome data for all participants.
Selective reporting (reporting bias)	Unclear risk	Unclear if protocol was registered.
Other bias	Low risk	No other sources of bias detected.

BIQ: Body Image Questionnaire; BMI: body mass index; CDC: Centres for Disease Control and Prevention; LSC: linear skin closure; n: number of participants; PSSC: purse‐string skin closure; POSAS: Patient and Observer Scar Assessment Scale; RCT: randomised controlled trial; SSI: surgical site infection; VAS: visual analogue scale.