Prevalence and correlates of self-reported medication non-adherence among older adults with coronary heart disease, diabetes mellitus, and/or hypertension

Background: Information about the prevalence and correlates of self-reported medication nonadherence using multiple measures in older adults with chronic cardiovascular conditions is needed. Objective: To examine the prevalence and correlates of self-reported medication nonadherence among community-dwelling elders with chronic cardiovascular conditions. Methods: Participants (n=897) included members from the Health, Aging and Body Composition Study with coronary heart disease, diabetes mellitus, and/or hypertension at Year 10. Self-reported nonadherence was measured by the 4-item Morisky Medication Adherence Scale (MMAS-4) and 2-item cost-related nonadherence (CRN-2) scale at Year 11. Factors (demographic, health status, and access to care) were examined for association with the MMAS-4 and then for association with the CRN-2 scale. Results: Nonadherence per the MMAS-4 and CRN-2 scale was reported by 40.7% and 7.7% of participants, respectively, with little overlap (3.7%). Multivariable logistic regression analyses found that black race was significantly associated with nonadherence per the MMAS-4 (P=0.002) and the CRN-2 scale (P=0.005). Other correlates of nonadherence per the MMAS-4 (with independent associations) included having cancer (P=0.04), a history of falls (P=0.02), sleep disturbances (P=0.04) and having a hospitalization in the previous 6 months (P=0.005). Conversely, being unmarried (P=0.049), having worse self-reported health (P=0.04) and needs being poorly met by income (P=0.02) showed significant independent associations with nonadherence per the CRN-2 scale. Conclusions: Self-reported medication nonadherence was common in older adults with chronic cardiovascular conditions and only one factor - race - was associated with both types. The research implication of this finding is that it highlights the need to measure both types of self-reported nonadherence in older adults. Moreover, the administration of these quick measures in the clinical setting should help identify specific actions such as patient education or greater use of generic medications or pill boxes that may address barriers to medication nonadherence.