Ahroni 1993.

Methods	Single‐centred, 2‐armed RCT comparing a calcium‐alginate dressing (Sorbsan, Aspen Medical, previously Dow B Hickman Inc.) with dry gauze (Owens Non‐Adherent dressing) undertaken in the USA. Duration of follow‐up: stated as 4 weeks, although some data collected beyond this point, but duration of this post‐4 week period not specified.
Participants	39 participants. Inclusion criteria: patients with diabetic foot ulcers that penetrated epidermis but did not significantly involve joint spaces, tendons or bone. Exclusion criteria: patients previously enrolled in the study; those with evidence of systemic toxicity (high fever, hypotension or metabolic decompensation); patients who required inpatient management of ulcers at time of initial evaluation (severe infection, ischaemia, extensive cellulitis, lymphangitis, deep necrosis, gangrene, crepitus or gas in tissue, or osteomyelitis or presumed deep infection); those unable or unwilling to comply with either daily wound care regimen or to come to weekly clinic visits.
Interventions	Group A (n = 20): 2 layers of calcium‐alginate dressing (Sorbsan, Aspen Medical) changed daily. Group B (n = 19): single layer of dry, fine mesh gauze (Owens Non‐Adherent dressing) changed twice a day. Co‐intervention: all wounds were cleansed with a half‐strength hydrogen peroxide solution and rinsed with normal saline.
Outcomes	Primary outcome: ulcer healing (number of ulcers healed at 4 weeks; number of ulcers healed at post 4 week follow‐up; healing rate mm2/day; relative odds of non‐healing). Secondary outcomes: amputations; adverse events. Health‐related quality of life; costs and ulcer recurrence not reported.
Notes	Trial data: Analysis 4.1 Funding source: Dow B Hickam Inc and Veterans Affair Rehabilitation: research and development.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote:"Subjects were randomly assigned to four weeks of daily dressing change with..." Comment: method of generating the random schedule not reported.
Allocation concealment (selection bias)	Unclear risk	Comment: no mention of allocation concealment in study report.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quote:"Because of differences in the appearance of the two dressings a blinded study was not feasible"  Comment: blinding of participants and personnel not done.
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quote:"Because of differences in the appearance of the two dressings a blinded study was not feasible"   Comment: blinding of outcome assessors not done.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Comment: no indication of incomplete outcome data/attrition in paper.
Selective reporting (reporting bias)	Low risk	Comment: based on paper only, protocol not obtained.
Other bias	Unclear risk	Comment: some differences in baseline characteristics between groups. Mean duration of ulcer 132.9 days in Group A and 74.9 days in Group B. Adjusted for in one analysis (logistic regression). Study was funded by commercial organisation.