A prospective randomised controlled trial and economic modelling of antimicrobial silver dressings versus non-adherent control dressings for venous leg ulcers: the VULCAN trial

Abstract

To examine the effectiveness and cost-effectiveness of antimicrobial silver-donating dressings for venous leg ulcers compared with simple non-adherent (also known as low-adherent) dressings. A pragmatic, prospective randomised controlled trial (RCT) and cost-effectiveness analysis of silver-donating versus low-adherent dressings in the treatment of venous leg ulcers. A non-randomised observational group was also recruited. Primary and secondary care services in the north and south of England (Sheffield and Exeter). Consenting patients with active ulceration of the lower leg that had been present for a period of greater than 6 weeks. Patients were randomised to receive either a silver-donating or non-silver low-adherent dressing applied beneath compression bandages or hosiery. The choice of dressing within these groups was left to clinician preference. Evaluation was by clinical assessment, supplemented by evaluation of quality of life and cost-effectiveness. The primary outcome measure was complete ulcer healing at 12 weeks in the index limb. Secondary measures were costs and quality-adjusted life-years (QALYs), cost-effectiveness, time to healing, and recurrence rate at 6 months and 1 year. In total, 304 participants were recruited to the clinical trial: 213 to the RCT and 91 to the observational arm. Within the RCT 107 were randomised to antimicrobial dressings and 106 to the control dressings. There were no significant differences (p > 0.05) between the two groups for the primary outcome measure of proportion of ulcers healed at 12 weeks (59.6% for silver and 56.7% for control dressings). The overall median time to healing was also not significantly different between the two groups (p = 0.408). A total of 24 patients had recurrent ulcers within 1 year; the recurrence rates of 11.6% (n = 11) for the antimicrobial and 14.4% (n = 13) for the control dressings were not significant. Mean utility valuations for both the EuroQol 5 dimensions (EQ-5D) quality of life questionnaire and Short Form 6 dimensions (SF-6D) utility index showed no differences for either group at 1, 3, 6 or 12 months. Compared with the control group, the antimicrobial group had an incremental cost of 97.85 pounds and an incremental QALY gain of 0.0002, giving an incremental cost-effectiveness ratio for the antimicrobial dressings of 489,250 pounds. Cost-effectiveness modelling of the results of the RCT showed that antimicrobial dressings were not cost-effective. No significant differences in either primary or secondary end points were found between the use of antimicrobial silver-donating dressings and the control group of low-adherent dressings. Modelling showed that antimicrobial silver dressings were not cost-effective. Current Controlled Trials ISRCTN72485131.