Aim: Adherence to using offloading devices is often low (1) and studies on adherence are difficult to compare due to methodological heterogeneity. The aim was to explore aspects of investigating adherence and provide recommendations for future studies.
Methods: A literature review was conducted of quantitative studies focusing on study designs, definitions of adherence, measurement methods, and conceptual frameworks.
Results: Most studies are cross-sectional and observational, limiting the potential to rule out confounding and establish causality (Table 1). Studies defining adherence as wearing time often use self-report to measure adherence, which can be unreliable. Studies that measure adherence with activity monitors often define 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 current research.
Conclusions: Future studies should be longitudinal; observational studies to identify non-adherent patient groups and factors that influence adherence, and experimental studies to evaluate interventions to improve adherence, focusing on these patient groups and factors. Adherence should be defined in terms of relative adherence to using offloading devices during all weight-bearing activities (walking, standing, etc.), and objective measurement of adherence should be used whenever possible. Conceptual frameworks should be defined to guide the choice of factors to include in the study and the analysis. Implementation of these recommendations could lead to a stronger evidence base in the future, supporting interventions to increase adherence and thereby improve outcomes for people with diabetic foot complications.