Classification of diabetic foot wounds is needed to compare treatments, to evaluate the outcome of clinical studies, to enable understanding of the pathophysiological processes leading to the diabetic foot, and to develop treatment strategies. Wound classification systems should be based on objective criteria, and measurements should be precise and clear. For clinical practice, in particular, they should be practical, easy to use and an important tool in clinical decision making. Problems encountered include: complex aetiology of ulcers, multiple ulcer types, imprecise clinical methods (e.g. wide inter-observer variation), evaluation over time, lack of an agreed glossary and general acceptance of definitions.
The key elements of a classification are size, infection, ischaemia and neuropathy. Some experts feel that associated risk factors should also be included.
Since the first developed classification systems (Meggit, 1976; Wagner, 1979), more than a dozen systems have been developed, but only a few have been clinically tested, albeit partially. Full testing is essential for evaluation for practical and scientific use.
The S(AD) SAD system (Macfarlane and Jeffcoate, 1999) deserves clinical validation as soon as possible. The authors point out that the developed classification is ‘not intended as a guide to management, but an aid to audit and research enabling certain types of ulcers to be identified for recruitment to prospective studies, as well as a means of comparing outcome between centres’. This implies, as many specialists feel, that we should work with two classifications: one for practical use and one for clinical research purposes. It is important to strive for consensus now.
The International Working Group on the Diabetic Foot (1999) agreed 43 definitions and glossaries, which should be validated. A classification of diabetic foot ulcers was not included because there was not enough clinical experience at that time. However, the board of the working group is now planning to organise an international conference with the experts in the field of classification systems to set a worldwide accepted general classification on diabetic foot ulcers for daily practice and clinical research. This should serve as part of an update on the second edition of The International Consensus and Practical Guidelines on the Diabetic Foot for 2003.