Foster 1994.

Methods	2‐armed RCT (not clear whether single‐ or multi‐centred) comparing a calcium‐alginate dressing (Kaltostat, ConvaTec) with a foam dressing (Allevyn, Smith & Nephew) undertaken in the UK. Duration of follow‐up: until ulcer healed, or for a maximum of 8 weeks.
Participants	30 participants. Inclusion criteria: patients > 18 years old with clean diabetic foot ulcers, willing and able to comply with study protocol.   Exclusion criteria: sloughy, necrotic or infected ulcers.
Interventions	Group A (n = 15): calcium‐alginate dressing (Kaltostat, ConvaTec). The dressing was moistened with saline. A perforated film absorbent dressing was used as a secondary dressing, this was secured with hypo‐allergic tape or a conforming bandage, depending on the state of the skin. Group B (n = 15): foam dressing (Allevyn, Smith & Nephew). Where surrounding skin was in good condition, the dressing was secured with hypo‐allergic tape. If the skin was atrophic or fragile, then no tape was applied, but a conforming bandage was used to secure the dressing. To apply the dressing to patients' lesser toes, a strip of polyurethane foam dressing was doubled over and fastened at the sides to form a sleeve that fitted over the toe.   Co‐interventions: none reported.
Outcomes	Primary outcome: ulcer healing (number of ulcers healed; ulcers improved; median time to healing). Secondary outcomes: adverse events. Health‐related quality of life, amputations, costs and ulcer recurrence not reported.
Notes	Trial data: Analysis 4.1 Dressing performance parameters such as patient comfort and ease of removal were assessed using 3‐point graded categorical scores. For each parameter the mean category score for each patient over the repeated dressing assessment was calculated. These data were not extracted, as this approach has not been validated and does not facilitate comparison between studies. Funding source: not reported.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote:"Thirty out patients entered the study and 15 were randomised to each dressing" Comment: method of generation of random schedule not reported.
Allocation concealment (selection bias)	Unclear risk	Comment: the process of randomising participants, including who did this was not reported.
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Comment: no mention of blinding in study report.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Comment: no mention of blinding in study report.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Comment: 4 participants were withdrawn from the alginate group (4/30 = 13%). There were no withdrawals from the foam group. It is not clear how data from the withdrawn participants were used.
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, e.g. mean age 61 years in Group A and 70 years in group Group B. Small sample size meant trial was at high risk of chance imbalance. Funding source: not reported