Thomas 1997.

Methods	A 2‐centred, open, randomised, controlled, comparative study with 199 participants (PUs n = 99, leg ulcers n = 100) Place of study NR. Assumed to be UK (Wales) where authors are located Follow‐up: 6 weeks Participants recruited from the community. No other details provided
Participants	Inclusion criteria: Grade 2 or 3 PUs (using the Stirling Classification), had an ulcer less then 10 mm deep and a maximum diameter of 8 cm (to allow a single dressing to cover the entire ulcer) Exclusion criteria: participants < 16 years, were known to have a history or poor compliance with medical treatment, had insulin‐dependent diabetes, were considered unlikely to survive the period of the study, had previously demonstrated adverse reactions to one of the dressings being tested, had wounds that were clinically infected In the hydropolymer foam dressing group at baseline (n = 50): age (years): mean 80.1, SD 10.2 gender: female (n = 35), male (n = 15) stage of PU: stage 2 (n = 27), stage 3 (n = 23) location of PUs: heel (n = 23), buttock (n = 6), sacrum (n = 10), hip (n = 2) and other (n = 9) duration of wound (months): < 1 month (n = 8), 1‐3 months (n = 21), > 3 months (n = 20), missing data (n = 1) In the hydrocolloid dressing group at baseline (n = 49): age (years): mean 78.6 SD, 14.3 gender: female (n = 33), male (n = 16) stage of PU: Grade 2 (n = 30), Grade 3 (n = 19) location of PUs: heel (n = 25), buttock (n = 2), sacrum (n = 6), hip (n = 4) and other (n = 12) duration of wound (months): < 1 month (n = 9), 1‐3 months (n = 18), > 3 months (n = 21), missing data (n = 1) Ethics committee approval obtained. Participants provided written informed consent prior to randomisation and collection of demographic data
Interventions	Group A: hydropolymer foam dressing (Tielle) until the wound healed, or for a maximum of 6 weeks (participants with PUs, n = 50) Group B: hydrocolloid dressing (Granuflex) until the wound healed, or for a maximum of 6 weeks (participants with PUs, n = 49)
Outcomes	Primary outcomes Incidence of healed PUs (categorised as "totally healed, improved, not healed, unchanged") Adverse events per participant (categorised as ulcer "deteriorated") Secondary outcomes Reduction in ulcer size (data not separated by wound type) Economic outcomes: NR
Notes	Only one ulcer per person Participants with PU were cared for using appropriate pressure‐relieving devices Adverse events linked to dressings (most frequently related to the adhesive nature of the dressings causing trauma) Funding source NR
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quotation: “...patients who…gave informed consent in writing were allocated to the two treatment groups on a randomised basis, using a system of sealed envelopes.” Comment: method of randomisation not described. Not clear if envelopes were sequentially numbered to ensure random sequence was maintained
Allocation concealment (selection bias)	High risk	Quotation: “An open, randomised, controlled, two‐centred, comparative study…” Comment: an open study. Group allocation not concealed
Blinding of participants and personnel (performance bias) All outcomes	High risk	Quotation: “An open, randomised, controlled, two‐centred, comparative study…” Comment: an open study. Participants and personnel not blinded to group allocation
Blinding of outcome assessment (detection bias) All outcomes	High risk	Quotation: “An open, randomised, controlled, two‐centred, comparative study…” Quotation: “To ensure accurate data collection, all dressing changes were undertaken by dedicated research nurses…” Comment: outcome assessment not blinded
Incomplete outcome data (attrition bias) All outcomes	Low risk	Quotation: "Details of all adverse events were documented. If a patient was withdrawn from the study, the reason was recorded and a decision made as to whether this was the result of an adverse reaction related to the use of the dressing or a non‐dressing related event." Comment: data reported for all participants randomised
Selective reporting (reporting bias)	Unclear risk	No direct quotation addressing this aspect Comment: limited information on which to judge
Other bias	Low risk	No direct quotation addressing this aspect Comment: none noted

ITT: intention‐to‐treat; NR: not reported; PU: pressure ulcer; RCT: randomised controlled trial