Gunatilake 2017.

Methods	Study design: randomised controlled trial Study grouping: parallel Ethics and informed consent: yes Follow‐up period: 42 ± 10 days Sample size estimate: not stated ITT analysis: yes number randomised: 92 number analysed: 92 Funding: non‐industry Pre‐registration: yes
Participants	Location: Texas, USA Intervention group: n = 46control group: n = 46 Mean age (SD): intervention group = 30.4 (5.7)control group = 29.7 (5) Inclusion criteria: 18 years of age with BMI 35 kg/m² at the time of delivery Exclusion criteria: women with skin or systemic infections, chorioamnionitis (defined by maternal fever + 1 clinical criteria), critical illness, or high‐risk for anaesthesia (ASA class P4, P5, or P6)
Interventions	Aim/s: to compare short‐term clinical outcomes among obese pregnant women undergoing caesarean delivery who received ciNPT or a standard‐of‐care dressing Primary outcome/s: SSO: unanticipated local inflammation, wound infection, seroma, haematoma, dehiscence, and need for surgical or antibiotic intervention Secondary outcome/s: not stated Group 1 (NPWT) intervention: a sterile, "peel‐and‐place" multilayer dressing (wicking fabric, reticulated foam, and adhesive) was placed over participant's closed incision. The dressing's tubing was then attached to a compact, portable negative pressure therapy unit that delivered 125 mmHg of continuous pressure to the dressing and removed exudates into a disposable canister. Duration of ciNPT was 5 to 7 days, immediately following surgery. Group 2 (control) intervention: Steri‐Strips (3M Health Care, ½ inch, St Paul, MN), sterile gauze, and Tegaderm (3M Health Care, transparent film dressings (non‐penetrable barrier)) were applied to the closed surgical incision for at least 1 day and no longer than 2 days. Study date/s: between 2012 and 2014
Outcomes	postoperative SSOs: included unanticipated local inflammatory response, prolonged drainage, fluid collection, dehiscence, and surgical site intervention surgical interventions: included antimicrobials for SSI, surgical drainage of the incision, surgical incision packing, adjunctive negative‐pressure therapy, debridement, or reoperation Validity of measure/s: wound scoring system; surgical site assessments included the supplementary outcomes of incisional pain scores at rest and with pressure on the closed incision, as measured by the Wong–Baker Faces Scale Time points: all participants were followed up postoperatively for 42 ± 10 days via periodic incisional assessments (postoperative days 1, 2, 6, 14, and 42).
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Study personnel obtained the next sequentially numbered, opaque randomisation envelope, which contained the randomly assigned treatment group for the participant.
Allocation concealment (selection bias)	Unclear risk	Study personnel obtained the next sequentially numbered, opaque randomisation envelope, which contained the randomly assigned treatment group for the participant.
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	Low risk	Although the postoperative examiner was privy to the treatment group, a standardised wound scoring system was utilised to minimise bias.
Incomplete outcome data (attrition bias) All outcomes	Low risk	An ITT analysis was used.
Selective reporting (reporting bias)	Unclear risk	Planned outcomes reported. Protocol pre‐registered on ClinicalTrials.gov (identifier NCT01450631).
Other bias	Low risk	None detected.