The effect of dementia on medication use and adherence among Medicare beneficiaries with chronic heart failure

Background: Alzheimer's disease and related disorders (ADRD) are prevalent in older adults, increase the costs of chronic heart failure (CHF) management, and may be associated with undertreatment of cardiovascular disease.

Objective: The purpose of our study was to determine the relationship between comorbid ADRD and CHF medication use and adherence among Medicare beneficiaries with CHF.

Methods: This 2-year (1/1/2006-12/31/2007) cross-sectional study used data from the Chronic Condition Data Warehouse of the Centers for Medicare and Medicaid Services. Medicare beneficiaries with evidence of CHF who had systolic dysfunction and Medicare Parts A, B, and D coverage during the entire study period were included. ADRD was identified based on diagnostic codes using the Chronic Condition Data Warehouse algorithm. CHF evidence-based medications (EBMs) were selected based on published guidelines: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, selected β-blockers, aldosterone antagonists, and selected vasodilators. Measures of EBMs included a binary indicator of EBM use and medication possession ratio among users.

Results: Of 9827 beneficiaries with CHF and systolic dysfunction, 24.2% had a diagnosis of ADRD. Beneficiaries with ADRD were older (80.8 vs 73.6 years; P < 0.0001) and more likely to be female (69.3% vs 58.1%; P < 0.0001). Overall EBM use was lower in patients with CHF and ADRD compared with patients with CHF but no ADRD (85.3% vs 91.2%; P < 0.0001). Lower use among those with ADRD was consistent across all EBM classes except vasodilators. Among beneficiaries receiving EBM, those with ADRD had a slightly higher mean medication possession ratio for EBM compared with those without ADRD (0.86 vs 0.84; P = 0.0001).

Conclusions: EBM medication adherence was high in this population, regardless of ADRD status. However, patients with ADRD had lower EBM use compared with those without ADRD. Low use of specific EBM medications such as β-blockers was found in both groups. Therefore, interventions targeting increased treatment with specific EBMs for CHF, even among patients with ADRD, may be of benefit and could help reduce CHF-related hospitalizations.