Tuuli 2017.

Methods	Study design: randomised controlled trial (abstract only available) Study grouping: parallel Ethics and informed consent: not recorded Sample size estimate: not recorded Follow‐up period: 30 days ITT analysis: yes number randomised: 120 number analysed: 120 Funding: non‐industry Pre‐registration: yes (NCT02578745). Registered 11 June 2012
Participants	Location: St Louis, Missouri, USA Intervention group: n = 60control group: n = 60 Mean age: not recorded Inclusion criteria: gestational age ≥ 23 weeks BMI ≥ 30 at the time of delivery planned or unplanned caesarean delivery (procedure in which NPWT is being tested) Exclusion criteria: not available for postoperative follow‐up contraindication to NPWT applicable to women undergoing caesarean: pre‐existing infection around incision site, bleeding disorder, therapeutic anticoagulation, allergy to any component of the dressing (e.g. silicone, adhesive tape)
Interventions	Aim/s: to assess the feasibility of a definitive RCT to test the effectiveness and safety of prophylactic NPWT in obese women after caesarean section Group 1 (NPWT) intervention: prophylactic NPWT with the PICO device (Smith & Nephew). Removed at discharge (usually on day 4) Group 2 (control) intervention: standard wound dressing (routine postoperative wound dressing consisting of layers of gauze and adhesive tape). The dressing was removed 24 to 48 hours. Study date/s: October 2016 to March 2016
Outcomes	Primary outcome/s: composite of superficial or deep surgical site infection; wound separation ≥ 2 cm; SSI; haematoma; seroma Secondary outcome/s: pain score on postoperative day 2 and skin reactions Validity of measure/s: wound infection defined by CDC criteria (information extracted from CTR) Time points: 30 days
Notes	Investigator contacted for additional details.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information in abstract to permit judgement.
Allocation concealment (selection bias)	Unclear risk	Insufficient information in abstract to permit judgement.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Evidence for participants: not possible Comment: unlikely to affect outcomes Evidence for personnel: not possible Comment: unlikely to affect outcomes
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Insufficient information in abstract to permit judgement.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Abstract indicated that 120 participants were randomised and 120 analysed. This was consistent with the number proposed in NCT02578745.
Selective reporting (reporting bias)	Low risk	Reporting was consistent with outcomes proposed in NCT02578745.
Other bias	Unclear risk	None detected. Independently funded trial, however no baseline data presented