Decision-making for early major amputation in selected diabetic foot ulcer patients with peripheral vascular disease

Objective: To estimate the costs from delaying major amputation in patients with concurrent diabetic foot ulcer and peripheral vascular disease. We seek to model economic benefits from saved costs from promoting timely major amputations among these patients. Methods: Retrospective modeling using data from National University Hospital, Singapore. We identified patients who might have delayed major amputations by applying a hierarchical clustering algorithm. We then modeled the transitions of all patients over time with a Markov process using a number of relevant health states to enable estimation of cost outcomes. We next summarized the expected changes to the bed days used and cost outcomes arising from reassigning some patients who may have had a delayed amputation to timely amputation. The findings from the sample were scaled to reflect national incidence rates for this disease for the years 2014-2019 in Singapore. Results and Conclusions: Nine of the 137 patients (6.57%) would be suitable for a major amputation at 3 months, yet in reality, their amputation was delayed. Based on this, and assuming a timely amputation is done for the entire population of patients in Singapore we expect annual savings of 264,791 bed days and $211 million in costs. These findings are preliminary and uncertain. The value of this paper is to show a method for estimating outcomes, report the findings from a small sample, and stimulate future research. New cohort studies might be designed to capture a wider range of outcomes and recruit a larger sample of individuals.