Cost-Effectiveness of Pressure-Guided-Offloading-Improved Custom-Made Footwear for People with Diabetes at High Risk of Plantar Foot Ulceration

Background: Custom-made footwear that improves offloading using in-shoe pressure-guided techniques, when worn as recommended, reduces the risk of diabetic foot ulcer recurrence. We aimed to assess the cost-effectiveness of this approach, as it requires extra investments in equipment and personnel, and implementation is not yet widespread. Methods: We conducted an economic evaluation using data from the DIAFOS RCT that randomized 171 participants at high ulcer risk to either pressure-guided-offloading-improved (intervention) or non-pressure-guided (usual care) custom-made footwear. The clinical outcome was the 18-month ulcer recurrence incidence, available from the RCT. Costs were modeled from a partial healthcare perspective using bottom-up unit cost calculation, with ulcer treatment costs obtained from reference data. Univariable regression analyses were executed to obtain incremental cost-effectiveness ratios (ICERs). Bootstrapping techniques accounted for uncertainty. Results: For the intervention, costs for ulcer recurrence were non-significantly lower (€−436; 95% CI: €−1434; €563) than for usual care. The ICER was €−8124 (i.e., costs saved to prevent one extra participant from having an ulcer), and the maximum probability for cost-effectiveness was 0.81. In the subgroup of participants who were adherent to wearing their prescribed footwear, costs for the intervention were non-significantly lower at €−1170 (95% CI: €−2595; €254), with ICER of €−5317, and a maximum probability for cost-effectiveness of 0.94. Conclusions: The use of in-shoe pressure-guided-offloading-improved custom-made footwear to help prevent diabetic foot ulcer recurrence is cost-effective with high probability when ulcer treatment costs are considered. Probability further increases when users adhere to their footwear. Future economic analyses should consider a full healthcare and societal perspective and use prospectively collected data on ulcer treatment costs.