Methodological considerations of investigating adherence to using offloading devices among people with diabetes

Abstract

Foot ulcers are a diabetic complication associated with significant morbidity, mortality, and amputation risk. Offloading devices prevent and heal foot ulcers, but adherence to using these devices is low. The reasons for nonadherence are unclear, and study results are difficult to compare due to methodological heterogeneity. This paper explores aspects of investigating adherence to using offloading devices among people with diabetes and provides recommendations for future studies, focusing on study designs, definitions of adherence, measurement methods, and conceptual frameworks. Most studies use a cross-sectional observational study design, limiting the potential to establish the temporal sequence between predictors and adherence, rule out confounding factors, and establish causality. Studies defining adherence as the length of time the device is worn have often used self-report to measure adherence, which may be unreliable. Studies using activity monitors to measure adherence have defined adherence as the number of steps taken with the device, which excludes weight-bearing activities where no steps are taken. Conceptual frameworks are not made explicit in the current quantitative research. It is concluded that future studies should use a longitudinal design with observational studies to identify patient groups prone to nonadherence and factors that influence adherence and experimental studies to evaluate interventions to improve adherence, focusing on these patient groups and factors. Furthermore, adherence should be defined in terms of relative adherence to using offloading devices during all weight-bearing activities, and objective measurement of adherence (using accelerometers and temperature monitors) should be used whenever possible. Clearly defined conceptual frameworks should guide the choice of factors to include in the study and the analysis of their interactions. By implementing these recommendations, research could provide a stronger evidence base in the future, supporting interventions to increase adherence and thereby improve outcomes for people with diabetic foot complications.

Should weight-bearing activity be reduced during healing of plantar diabetic foot ulcers, even when using appropriate offloading devices?

“…Although several studies included 'non-removable' devices, we recommend that adherence should always be assessed and reported as no device is strictly non-removable [61,62]. Rather, so-called non-removable devices imply different physical or psychological thresholds that patients can accept to prevent their future self from removing the device [63].…”

Predictors of adherence to wearing therapeutic footwear among people with diabetes

“…Studies on footwear adherence have been criticized for not defining the conceptual framework, resulting in high heterogeneity, and for focusing on a narrow range of factors, typically those related to the patient, therapy and health condition [32]. This study included a wide range of factors and is the first study to use the entirety of the Health Belief Model to study the predictors of footwear adherence.…”

In-shoe pressure analysis in patients with a history of diabetes-related foot ulceration: a mixed methods study

“…Macfarlane and Jensen (13) reported that 12% (n = 6) of participants wore prescribed MGF > 80% of the time at home compared to 26% (n = 13) outside the home, while Waaijman et al (12) reported mean adherence of 61% at home compared to 87% adherence away from home for 107 participants with previous DFU, and this difference was statistically signi cant (p < 0.01). The challenge of comparing the ndings of the current study with previous research is that adherence is not frequently reported separately for indoor and outdoor use, however, this is important given the signi cant difference in reported adherence between these two conditions (24).…”