Trajectories of Antidiabetic Medication Adherence in Older Adults and the Effect of Depression and Anxiety Symptoms

Objectives: Common mental health disorders, such as anxiety and depression, significantly impact medication adherence in various chronic conditions. However, few studies have captured the evolving nature of adherence behavior, indicating a need for further investigation. The objectives were to describe adherence trajectories to antidiabetic medications among older patients and to explore the potential association between these trajectories and the presence of anxiety and depression. Methods: We conducted a secondary analysis of the Enquête sur la santé des aînés et l'utilisation des services de santé study, involving 282 elderly participants who were prevalent users of antidiabetic medications. Medication adherence was measured using claims data over 12 months. Group-based trajectory modeling was employed to identify distinct adherence trajectories. The association between the presence of common mental health disorders, assessed using self-reported symptoms and diagnostic codes from medico-administrative data, and adherence trajectories was estimated through multinomial logistic regressions. Results: Four distinct adherence trajectories were identified and defined as low adherence (6.7%), fair adherence (18.1%), high adherence (37.9%), and nearly perfect adherence (37.2%). These patterns were also stable during the 12-month follow-up period. No significant association was found between common mental health disorders and medication adherence trajectories in this cohort, even after adjusting for potential confounders. Conclusion: Older patients with diabetes mostly depicted high adherence. Depression or anxiety did not impact adherence trajectories. However, our study was underpowered to detect small-to-moderate effects of these common mental health disorders.