Silver based wound dressings and topical agents for treating diabetic foot ulcers.

BACKGROUND Foot ulceration affects 15-20% of people with diabetes. It is a major precursor to amputation in this patient group, and early and appropriate treatment provides the greatest opportunity for healing. The use of silver for its antimicrobial properties has re-emerged, and modern wound dressings that release a sustained amount of free silver ions, are now widely used in wound management. OBJECTIVES To evaluate the effects of silver-containing dressings and topical agents on infection rates and healing of diabetes related foot ulcers. SEARCH STRATEGY Searches were made of the Cochrane Wounds Group Specialised Register (August 2005), the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library Issue 3 2005) MEDLINE (1966 to October week 2 2004), EMBASE (1980 to October week 2 2004) and CINAHL (1982 to October week 2 2004). The Journal of Wound Care (Volume 12/13 Issues 1-10) was hand-searched. Manufacturers, researchers and local and international wound groups were contacted in order to identify unpublished trials. Web sites for wound groups and World Wide Wounds (www.worldwidewounds.com) were searched. SELECTION CRITERIA Randomised controlled trials and non-randomised controlled clinical trials were considered for inclusion. Studies were included if they involved participants with Type 1 or Type 2 diabetes and related foot ulcers, met the requirements for randomisation, allocation and concealment where appropriate, and compared the intervention with a placebo or a sham dressing, an alternative non silver based dressing or no dressing, and reported outcomes that represent healing rate or infection. DATA COLLECTION AND ANALYSIS Two authors independently evaluated the papers identified by the search strategy against the inclusion criteria but identified no trials eligible for inclusion in the review. It was not possible to perform planned subgroup and sensitivity analysis in the absence of data. In future, if eligible trials become available, a random effects model will be applied for meta-analysis in the presence of statistical heterogeneity (estimated using the I(2) statistic). Dichotomous outcomes will be reported as risk ratios with 95% confidence intervals (CI), and continuous outcomes as weighted mean differences (WMD) with 95% CI. Statistical significance will be set at P value < 0.05 for all outcomes and the magnitude of the effect will be estimated by calculating the number needed to treat (NNT) with 95% CI. MAIN RESULTS No studies were identified that met with the inclusion criteria AUTHORS' CONCLUSIONS Despite the widespread use of dressings and topical agents containing silver for the treatment of diabetic foot ulcers, no randomised trials or controlled clinical trials exist that evaluate their clinical effectiveness. Trials are needed to determine clinical and cost-effectiveness and long term outcomes including adverse events.