A New Wound-Based Severity Score for Diabetic Foot Ulcers

Beckett S, Witte M, Wicke C, Konigrainer A, Coerper S. Diabetes Care. 2006;29(5):988-992.

Diabetic foot ulcers are a major cause of concern and create a significant financial burden within the diabetes-related health care sphere. Main risk factors for development of foot ulcers and diabetes related amputations are peripheral neuropathy, peripheral vascular disease, abnormal plantar pressure load, and infection. Accordingly, due to its substantial impact, attempts have been made to create a classification system that helps assess the severity of disease. This classification system should implement a communication bridge between healthcare providers, affect daily clinical management and provide information about healing. The aim of this study was to describe the influence of a scoring system on clinical outcome based on the chances for healing and risk of amputation. 

A total of 1000 patients with diabetes had follow up visits between 1997 and 2004. The follow up was documented for 1 year or until a healing or amputation took place earlier. Wounds, on either foot or toe, were assessed at the initial visit and were categorized and graded according to the deepest tissue involved (dermis as grade 1, subcutaneous as grade 2, fascia as grade 3, muscle as grade 4, and bone as grade 5). Soft tissue infection was defined by the presence of pus-like discharge combined with two other local signs. Additionally, healing was defined as absolute epithelization and minor or major amputation. Amputation rate consisted of the percentage of patients undergoing either major or minor amputations. The diabetic ulcer severity score (DUSS) ranged from 0 to 4 using 4 wound based clinical variables. Patients with multiple ulcers were classified as 1 and those with singe ulcers as 0. Ulcers located on the toe were scored as 1 and on the toe as 0. Probing to the bone was defined as yes=1 and no=0 and an absence of palpable pedal pulse was given a score of 1 and the presence of it was a score of 0.

The initial results showed 29 ulcers classified as grade 1 (2.9%), 635 as grade 2 (63.5%), 20 as grade 3 (2.0%), 47 as grade 4 (4.7%) and 269 as grade 5 (26.9%). Additionally, results also indicated that the median initial wound area was approximately 0.9 cm², median wound history of 31 days, and median number of visits was 5. Moreover, 40.4% of patients had more than one ulcer at the initial visit. According to the grading scale, the chance of healing was lower and independently associated with respect to nonpalpable pulses (P< .0009), probing to bone (P< .00019), adult lacerations (P< .00001), and foot versus toe ulcerations (P< .00001). Furthermore, due to immediate wound-therapy, soft tissue infection did not have any influence on healing (P=0.5324). Subsequently, when the patients were divided into subgroups, different probabilities of healing were seen. There was a 93% chance of healing of uncomplicated ulcers and a 57% probability for ulcers with a severity score of 4.

A total of 99 minor amputations were performed and the overall major amputation rate was 2.6%. Interestingly, probability of healing decreased with an increasing DUSS. There was also an increase in wound size from 0.3 to 2.7 cm2 and of wound length from 29 to 61 days relative to DUSS. Patients with a higher severity score were also more likely to be hospitalized and to undergo surgery.