Randomised controlled trial of the use of three dressing preparations in the management of chronic ulceration of the foot in diabetes

Objectives: To determine the comparative effectiveness and cost-effectiveness of three dressing products, N-A®, Inadine® and Aquacel®, for patients with diabetic foot ulcers, as well as the feasibility and consequences of less frequent dressing changes by health-care professionals. Design: A multicentre, prospective, observer-blinded, parallel group, randomised controlled trial, with three arms. Setting: Established expert multidisciplinary clinics for the management of diabetic foot ulcers across the UK. Participants: Patients over age 18 with type 1 or type 2 diabetes with a chronic (present for at least 6 weeks) full-thickness foot ulcer (on or below the malleoli) not penetrating to tendon, periosteum or bone, and with a cross-sectional area between 25 and 2500 mm2. Interventions: Participants were randomised 1:1:1 to treatment with one of N-A (a non-adherent, knitted, viscose filament gauze), Inadine (an iodine-impregnated dressing), both traditional dressings, or Aquacel, a newer product. Main outcome measures: The primary outcome measure was the number of ulcers healed in each group at week 24. Secondary measures included time to healing, new ulcerations, major and minor amputations, and episodes of secondary infection. Results: A total of 317 patients were randomised. After 88 withdrawals, 229 remained evaluable. A greater proportion of smaller (25–100 mm2 ulcers healed within the specified time (48.3% versus 37.3%; p = 0.048). There was, however, no difference between the three dressings in terms of percentage healed by 24 weeks, or in the mean time to healing, whether analysed on the basis of intention to treat (Inadine 44.4%, N-A 38.7%, Aquacel 44.7%; not significant) or per protocol (Inadine 55.2%, N-A 59.4%, Aquacel 63.0%; not significant). There was no difference in the quality of healing, as reflected in the incidence of recurrence within 12 weeks. Likewise, there was no difference in the incidence of adverse events, although a greater proportion of those randomised to the non-adherent dressings were withdrawn from the study (34.9% versus 29.1% Aquacel and 19.4% Inadine; p = 0.038). The only statistically significant difference found in the health economic analysis was the cost associated with the provision of dressings (mean cost per patient: N-A £14.85, Inadine £17.48, Aquacel £43.60). The higher cost of Aquacel was not offset by the fewer dressings required. There was no difference in measures of either generic or condition-specific measures of quality of life. However, there was a significant difference in the change in pain associated with dressing changes between the first and second visits, with least pain reported by those receiving non-adherent dressings (p = 0.012). There was no difference in the costs of professional time, and this may relate to the number of dressing changes undertaken by non-professionals. Fifty-one per cent of all participants had at least one dressing change undertaken by themselves or a non-professional carer, although this ranged from 22% to 82% between the different centres. Conclusions: As there was no difference in effectiveness, there is no reason why the least costly of the three dressings could not be used more widely across the UK National Health Service, thus generating potentially substantial savings. The option of involving patients and non-professional carers in changing dressings needs to be assessed more formally and could be associated with further significant reductions in health-care costs. Trial registration: Current Controlled Trials ISRCTN78366977