Robert S Kirsner, Gary Delhougne, Richard J Searle

Lower extremity ulcers such as venous leg ulcers (VLUs) and diabetic foot ulcers (DFUs) have a major clinical and economic impact on patients and providers. The purpose of this economic evaluation was to determine the cost-effectiveness of single-use negative pressure wound therapy (sNPWT) compared with traditional NPWT (tNPWT) for the treatment of VLUs and DFUs in the United States. A Markov decision-analytic model was used to compare the incremental cost and ulcer weeks avoided for a time horizon of 12 and 26 weeks using lower extremity ulcer closure rates from a published randomized controlled trial (N = 161) that compared sNPWT with tNPWT. Treatment costs were extracted from a retrospective cost-minimization study of sNPWT and tNPWT from the payer perspective using US national 2016 Medicare claims data inflated to 2018 costs and multiplied by 7 to estimate the weekly costs of treatment for sNPWT and tNPWT. Two (2) arms of the model, tNPWT and sNPWT, were calculated separately for a combination of both VLU and DFU ulcer types. In this model, a hypothetical cohort of patients began in the open ulcer health state, and at the end of each weekly cycle a proportion of the cohort moved into the closed ulcer health state according to a constant transition probability. The costs over the defined timescale were summed to give a total cost of treatment for each arm of the model, and then the difference between the arms was calculated. Effectiveness was calculated by noting the incidence of healing at 12 and 26 weeks and the total number of open ulcer weeks; the incremental effectiveness was calculated as sNPWT effectiveness minus tNPWT effectiveness. Data were extracted to Excel spreadsheets and subjected to one-way sensitivity, scenario (where patients with unhealed ulcers were changed to standard care at 4 or 12 weeks), probabilistic, and threshold analyses. sNPWT was found to provide an expected cost saving of $7756 per patient and an expected reduction of 1.67 open ulcer weeks per patient over 12 weeks and a cost reduction of $15 749 and 5.31 open ulcer weeks over 26 weeks. Probabilistic analysis at 26 weeks showed 99.8% of the simulations resulted in sNPWT dominating tNPWT. Scenario analyses showed that sNPWT remained dominant over tNPWT (cost reductions over 26 weeks of $2536 and $7976 per patient, respectively). Using sNPWT for VLUs and DFUs is likely to be more cost-effective than tNPWT from the US payer perspective and may provide an opportunity for policymakers to reduce the economic burden of lower extremity ulcers.