Fig. 2

Study design and main procedures for participants. All follow-up visits can deviate a maximum 2.5 weeks from the scheduled timepoint. * = An unscheduled visit becomes a scheduled visit when a participant develops an ulcer. This visit will be repeated every 3 months if an ulcer is not healed, which is the same frequency as normal follow-up visits. ‡ = Regular final visit will be at 12 months. However, if a participant has an ulcer at 12 months, there will be extra follow-up visits after the final visit. These will take place at 15 and 18 months or, if the ulcer has healed earlier, at 2 weeks after healing. The extra follow-ups follow the procedures of the unscheduled visit. ** = For enhanced therapy group only. † = the study questionnaire consists of a combination of multiple validated questionnaires, including adapted versions of the Monitor Orthopedic Footwear, treatment satisfaction questionnaire, COM-b (Capabilities, Opportunities, Motivations) questionnaire, and an assessment of knowledge about foot care based on the PIN questionnaire (Patients’ Interpretation of Neuropathy). ENROL, enrolment visit; BASE, baseline visit; RAND, randomization visit; FU_x, follow-up visit (numbered by visit number); UV, unscheduled visit; FV, final visit; SF-36, quality of life questionnaire; EQ-5D-5L, quality of life questionnaire measuring quality-adjusted life years; iMTA, Institute for Medical Technology Assessment questionnaires on medical consumption and productivity costs; CWIS, Cardiff Wound Impact Schedule questionnaire