Chaloner 2004.

Methods	Randomised controlled trial conducted in the UK
Participants	40 patients with chronic venous leg ulcers recruited from 3 centres within primary care setting: Group 1: 20 participants Group 2: 20 participants Median ulcer duration, weeks (range): 52 (6 weeks to 20 years), breakdown per group not provided Median ulcer area, cm2 (range): 4.9 (0.9 to 196.1), breakdown per group not provided The available information suggests that all participants had bacterial colonisation of ulcers at baseline, but not stated whether any were clinically infected
Interventions	Group 1: silver‐impregnated polyurethane foam dressing (Avance) Group 2: 5‐layer silver impregnated dressing comprising two layers of an absorbent inner core sandwiched between three layers of silver‐coated, low‐adherent polyethylene net (Acticoat 7) All participants received four‐layer compression bandage (Profore), providing 40 mmHg at the ankle Duration of treatment was 12 weeks unless the ulcer healed before this time
Outcomes	Number (%) of ulcers healed at 12 weeks: Group 1: 7/20 (35) Group 2: 10/20 (50) Median percentage (%) change in ulcer area at 12 weeks: Group 1: ‐80.4% Group 2: ‐95.1% The trial authors reported that the between‐group difference was not statistically significant but did not provide the P value Seondary outcomes: The trial authors reported that there was a greater reduction in the total number of bacteria (colony forming units per cm2) in Group 2 compared with Group 1, but the between‐group difference was not statistically significant (data and P value not provided) The trial authors reported that more pathogenic bacterial groups were eliminated in Group 2 compared with Group 1, including Staphylococcus aureus, beta‐haemolytic streptococci, anaerobes and coliforms. No further data or P values were provided Adverse events at 12 weeks: The trial authors reported that a higher proportion of participants in Group 2 reported no pain from the study ulcer and a healthy condition of the peri‐ulcer skin compared with Group 1
Notes	Data were extracted from a conference poster and abstract, and further details were confirmed through correspondence with the study author. A full report was not available Microbiological analysis (bacterial counts and bacterial identification) was by wound swabs taken at 0, 2, 4, 8 and 12 weeks. No details of techniques used were provided The median baseline value in ulcer duration as recorded above was taken from the conference abstract (52 weeks); the conference poster reported a different value (34.7 weeks) In the conference abstract, the trial authors reported: "the rate of healing was on average 16.8% faster" in Group 2 compared with Group 1, but did not explain how this statistic was estimated; also, contradictory information was given in the poster, which suggested that participants in Group 1 healed faster, on average Withdrawals (available from a brief interim report only): Group 1: 2 participants withdrew because of adverse events (further details not provided) Group 2: no information provided
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random sequence generation achieved using computer‐generated programme (confirmed through email communication with trial author)
Allocation concealment (selection bias)	Unclear risk	"A prospective, multi‐centre, randomised, comparative study to compare the effects of Acticoat 7 antimicrobial barrier dressing to Avance silver impregnated foam film dressing in the treatment of chronic venous leg ulcers" Comment: no details of allocation concealment reported
Blinding (performance bias and detection bias) Participant blinded to the intervention	Unclear risk	No information on participant blinding reported
Blinding (performance bias and detection bias) Outcome assessor blinded to the intervention	Unclear risk	No information on outcome assessor blinding reported
Incomplete outcome data (attrition bias) Drop out rate described	Unclear risk	"In the Avance group.....2 patients had been withdrawn due to adverse reactions" Comment: The above information was taken from a brief, interim report. No information on withdrawals was provided in relation to the Acticoat 7 group, and no information was available for either group at the final analysis
Incomplete outcome data (attrition bias) Drop out rate acceptable	Unclear risk	"In the Avance group.....2 patients had been withdrawn due to adverse reactions" Comment: The above information was taken from a brief, interim report. No information on withdrawals was provided in relation to the Acticoat 7 group, and no information was available for either group at the final analysis
Incomplete outcome data (attrition bias) ITT analysis	Unclear risk	From conference abstract: "Results from 40 patients have demonstrated" From conference poster: "The primary analysis could only be conducted on 18 (45%) patients who had a baseline bacteria count and at least one post baseline bacteria count" Comment: no statement as to whether analysis conducted per protocol or according to intention‐to‐treat
Baseline factors comparable	Unclear risk	Baseline participant characteristics were not presented per group