The financial burden of surgical and endovascular treatment of diabetic foot wounds

Objective: The cost of treating diabetes-related disease in New Zealand is increasing and is expected to reach New Zealand dollars (NZD) 1.8 billion in 2021. The financial burden attached to the treatment of diabetic foot wounds is difficult to quantify and reported costs of treatment vary greatly in the literature. As of yet, no study has captured the true total cost of treating a diabetic foot wound. In this study, we investigate the total minimum cost of treating a diabetic foot ulcer at a tertiary institution. Methods: A retrospective audit of hospital and interhospital records was performed to identify adult patients with diabetes who were treated operatively for a diabetic foot wound by the department of vascular surgery at Auckland Hospital between January 2009 and June 2014. Costs from the patients' admissions and outpatient clinics from their first meeting to the achievement of a final outcome were tallied to calculate the total cost of healing the wound. The hospital's expenses were calculated using a fully absorbed activity-based costing methodology and correlated with a variety of demographic and clinical factors extracted from patients' electronic records using a general linear mixed model. Results: We identified 225 patients accounting for 265 wound episodes, 700 inpatient admissions, 815 outpatient consultations, 367 surgical procedures, and 248 endovascular procedures. The total minimum cost to the Auckland city hospital was NZD 10,217,115 (NZD 9,886,963 inpatient costs; NZD 330,152 outpatient costs). The median cost per wound episode was NZD 29,537 (NZD 28,491 inpatient costs; NZD 834 outpatient cost). Wound healing was achieved in 70% of wound episodes (average length of healing, 9 months); 19% of wounds had not healed before the patient's death. Of every 3.5 wound episodes, one required a major amputation. Wound treatment modality, particularly surgical management, was the strongest predictor of high resource utilization. Wounds treated with endovascular intervention and no surgical intervention cost less. Surgical management (indiscriminate of type) was associated with faster wound healing than wounds managed endovascularly (median duration, 140 vs 224 days). Clinical risk factors including smoking, ischemic heart disease, hypercholesterolemia, hypertension, and chronic kidney disease did not affect treatment cost significantly. Conclusions: We estimate the minimum median cost incurred by our department of vascular surgery in treating a diabetic foot wound to be NZD 30,000 and identify wound treatment modality to be a significant determinant of cost. While readily acknowledging our study's inherent limitations, we believe it provides a real-world representation of the minimum total cost involved in treating diabetic foot lesions in a tertiary center. Given the increasing rate of diabetes, we believe this high cost reinforces the need for the establishment of a multidisciplinary diabetic foot team in our region.