Short-Term Efficacy of a Multi-Modal Intervention Program to Improve Custom-Made Footwear Use in People at High Risk of Diabetes-Related Foot Ulceration.

Background: Wearing custom-made footwear is key in diabetes-related foot ulcer prevention. However, adhering to wearing footwear is challenging, in particular at home. Evidence-based interventions with proven effect are needed, but scarce. We developed a multi-modal intervention to improve custom-made footwear use, and investigated short-term efficacy. Methods: We used a multidisciplinary multiphase approach to develop a three-modality intervention: structured education, motivational interviewing, and custom-made indoor footwear. To assess efficacy, we measured mean 2-week wearing time of custom-made footwear with a validated sensor, at baseline and after three months (primary outcome), and in the two weeks directly before and after each modality was administered (secondary outcomes). We assessed differences between timepoints using within-subjects paired t-tests. Results: 53 participants with high risk for ulceration were included: 30 with low [<8 h/day] baseline adherence), 17% females, mean age 66 (SD: 10) years, all with peripheral neuropathy and a recent foot ulcer (mean time since healing: 6 (SD: 9) months). Wearing time increased non-significantly from 4.0 (SD: 2.5) at baseline to 5.5 (SD: 4.3) after three months in the low adherence group (p = 0.068); this was 11.9 (SD: 2.3) to 12.0 (SD: 2.8) in the high adherence group (p = 0.898). Following provision of indoor footwear, wearing time increased significantly for low baseline adherence (∆2.7 h/day (95% CI: 1.0-4.4; p = 0.004) and high baseline adherence (∆2.0 h/day (95% CI: 0.5-3.4; p = 0.010). Following structured education, wearing time increased non-significantly in those with low baseline adherence (∆1.0 h/day (95% CI: -0.2-2.2; p = 0.098). Following motivational interviewing, wearing time remained similar in both groups. Conclusions: The multi-modal intervention program combining structured education, motivational interviewing and custom-made indoor footwear did not result in a statistically significant improvement in the wearing time of custom-made footwear after three months. However, significant improvements followed the provision of indoor footwear, and clinically relevant improvements followed structured education in people with low adherence, providing avenues for implementation and research.