How to measure success in treating chronic leg ulcers.

Optimising the care of patients with leg ulcers is prob‐ lematic not least because of the lack of universally accepted evidence based guidelines.1 Several systematic reviews into the effects of, for example, debridement, compression, topical treatments (including dressings), antimicrobial agents, and newer treatments (such as topical negative pressure devices) have predictably led to the conclusion that more research is needed.2‐7 In the United Kingdom, clinical guidelines from bodies such as the National Institute for Health and Clini‐ cal Excellence (NICE) or the Scottish Intercollegiate Guidelines Network (SIGN) are either not available or have limited value. Three linked studies concern the efficacy and costs of treatments for leg ulcers.8‐10 The management of chronic wounds, healing by sec‐ ondary intention, is challenging—a multidisciplinary approach is generally thought to be the best option.11 12 The importance of developing systems, structures, and appropriate remuneration for caring for patients with such wounds has only recently been recognised.13 The obvious measure of success in evaluating interventions in wound healing is complete healing. As yet, however, no single intervention has produced both clinically and statistically significant results, which has resulted in the limited adoption of new technologies. The evidence needed to evaluate treatment inter‐ ventions for leg ulcers has three components—effi‐ cacy, which could include debridement or healing; efficiency, which may include frequency of dressing change or admission to hospital; and effectiveness, which could assess patients’ quality of life or cost effec‐ tiveness.14 The three linked studies illustrate some of these factors.8‐10 Dumville and colleagues report a three‐armed, ran‐ domised, controlled trial that compared the effects of hydrogel, loose larvae, and bagged larvae on debride‐ ment and healing of leg ulcers.8 Larval therapy did not increase the rate of healing or reduce bacterial load compared with hydrogel. On a positive and clini‐ cally relevant note, however, the study found a highly significant effect of bagged or free maggots on the removal of slough and necrotic tissue (debridement) compared with hydrogel. The authors do not speculate why healing was not enhanced after effective debri‐ dement. The study’s primary end point was healing, but this may be inappropriate, especially as venous and mixed arterial and venous ulcers were included. Effective debridement may have been a more useful measure of success and more valuable to clinicians in certain circumstances. A cost effectiveness analysis of the trial found that debridement of sloughy venous leg ulcers with larvae probably costs about the same as using hydrogel.9 However, cost effectiveness is difficult to measure accurately using these data sets because the ran‐ domised controlled trial design will exclude many patients with this condition and it is therefore difficult to demonstrate cost effectiveness with confidence; comprehensive evaluation should include studies specifically designed to study this measure. Debridement is central to the effective management of all chronic wounds. In venous ulcers, which are relatively superficial, this can be simply, quickly, and completely achieved by sharp debridement; a relatively low‐tech intervention that is easily learnt. This said, clinicians who manage chronic wounds and do not have the necessary skills or access to equipment may be attracted to alterna‐ tive, relatively untested, methods of debridement such as larval therapy. The third linked study is a systematic review and meta‐analysis of two forms of compression bandages (four layer bandage and short stretch bandage) in the treatment of venous leg ulcers. It concludes that the four layer bandage significantly reduced the time to heal‐ ing (hazard ratio 1.31, 95% confidence interval 1.09 to 1.58). Short stretch bandages are useful in patients who are mobile and should be replaced daily. Although the four layer bandage system is effective, its bulkiness may lead to non‐adherence in some patients. It is designed to be left in place for several days, so its use is limited in highly exuding ulcers because dressings may need to be changed more often. Therefore, although four layer bandages may improve healing overall, the choice of compression bandage should reflect the patient’s specific needs and circumstances. It may be unrealistic to use complete healing as the primary outcome measure in wound healing studies, and time to healing may be an equally valid outcome measure. Effective debridement may help patients, clini‐ cians, and the health service by improving healing and avoiding ineffective treatment. Although further research is needed, to show the efficacy of debridement by any method, the immediate priority should be to educate health professionals how to manage leg ulceration. Rather than using healing as the only measure of success, a common error that has been made in recent years, it would be more appropriate to adopt a broader based approach to the management of the challenging and complex problems inherent in the treatment of chronic wounds. lo ui se m ur ra y / a la m y