Association between depressive and anxiety disorders and adherence to antihypertensive medication in community-living elderly adults

Objectives: To identify the determinants of antihypertensive medication adherence in community-living elderly adults.

Design: Longitudinal observational study.

Setting: Population-based health survey in the province of Quebec, Canada.

Participants: Data from a representative sample (N = 2,811) of community-dwelling adults in Quebec aged 65 and older participating in the Étude sur la Santé des Aînés study. The final study sample analyzed consisted of 926 participants taking antihypertensive drugs during the 2 years of the study.

Measurements: Adherence to antihypertensive medication was measured using days of supply obtained during a specified time period. Depression and anxiety disorders were assessed using Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria, and physical health status was measured using the Charlson Comorbidity Index. Other factors considered were age, education, marital status, annual family income, and number of antihypertensive drugs that participants used.

Results: Mean antihypertensive proportion (percentage) of days supplied in was 92.5% in Year 1 and 59.4% in Year 2. The presence of depression and anxiety disorders and the number of antihypertensive medications significantly predicted medication adherence. The sex by depression and anxiety disorders interaction term was significant.

Conclusion: Adherence to antihypertensive medication was significantly associated with depression and anxiety disorders in men but not women. The treatment of depression and anxiety disorders in individuals with hypertension may be helpful in improving medication adherence rates and healthcare outcomes.