Osther 1995.

Methods	RCT Methods to control for contributory patient factors: none
Participants	Age: Group 1: median 75 Group 2: median 77 Gender: Group 1 female 53%; Group 2 56.7% Types of incisions: Group 1: median 9%; paramedian 59%; oblique 13%; transverse 19% Group 2: median 10.6%; paramedian 53.8%; oblique 11.5%; transverse 23.1% Types of surgery: not described Contamination classification of included participants: not described Preoperative antibiotic use: not described Prognostic patient factors: Group 1: malignancy 42% Group 2: malignancy 47.1% Inclusion criteria: undergoing laparotomy with ≥ 1 criteria for impaired wound healing including age > 70 years, COPD for at least 10 years, intra‐abdominal malignancy or diffuse peritonitis Exclusion criteria: appendectomy through an oblique muscle‐splitting incision, laparotomy through a previous scar
Interventions	Comparisons reported: Group 1: Sutures: PGA (multifilament, fast absorbable) Suture technique: interrupted Closure method: mass Group 2: Sutures: polyglyconate (monofilament, slowly absorbable) Suture technique: interrupted Closure method: mass Characteristics of surgeons: not described
Outcomes	Hernia: palpable protruding swelling and fascial defect Follow‐up duration: 10 days, 3 months and 12 months Wound infection: purulent discharge leading to surgical drainage Dehiscence: fascial disruption with operative closure necessary Sinus/fistula: no definition provided
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random numbers using Geigy scientific tables
Allocation concealment (selection bias)	Unclear risk	Not explicitly described
Blinding (performance bias and detection bias) All outcomes	Unclear risk	Not explicitly described
Incomplete outcome data (attrition bias) All outcomes	Low risk	All participants accounted for. Loss to follow‐up described by group
Selective reporting (reporting bias)	High risk	Dehiscence not reported despite pre‐specified
Other bias	Low risk	The study appears to be free of other sources of bias