Investigating Nonadherence in an Integrated Diabetic Limb Salvage Programme: Reasons, Associated Factors, and Impacts on Care Outcomes

Adherence to treatment plans is crucial for patients with diabetic foot ulcers (DFUs) to achieve positive outcomes. With limited understanding of nonadherence and its impacts on care outcomes, this study aimed to explore the reasons and factors associated with nonadherence in an integrated diabetic limb salvage (DLS) programme and evaluate its effects on care outcomes. This study included 2798 DFU patients who were enrolled in an integrated DLS programme across multiple institutions in central and northern Singapore from 2020 to 2021. Reasons for nonadherence were obtained via telephone interviews. Factors associated with nonadherence were identified using multiple logistic regression. Differences in one-year outcomes, including minor and major lower extremity amputation (LEA), mortality, LEA-free survival, and healthcare utilisation between adherent and nonadherent patients, were examined based on a significance level of P < .05. Nonadherence was observed in 40.2% of patients, with higher rates among younger patients, Malays and Indians, and those with higher HbA1c levels. Patient-related factors were the most commonly reported reasons for missed appointments (50.4%). Compared to adherent patients, nonadherent patients exhibited a relatively higher minor LEA rate (13.0% vs 10.2%, OR = 1.18, 95% CI: 0.93, 1.51), lower mortality rate (8.6% vs18.1%, OR = 0.50, 95% CI: 0.39, 0.65), higher overall LEA-free survival (76.4% vs 71.1%, OR = 1.27, 95% CI: 1.06, 1.53), and more hospitalisations (IRR = 1.22, 95% CI: 1.11, 1.33) and emergency visits (IRR = 1.27, 95% CI: 1.16, 1.39). While nonadherent patients showed relatively higher minor LEA rates and more healthcare utilisation, they also exhibited lower mortality and higher LEA-free survival. This suggests that nonadherence in this population may be associated with complex patient characteristics and behaviours that warrant further investigation to tailor interventions effectively.