Association Between Poorer Cognitive Function and Reduced Objectively Monitored Medication Adherence in Patients With Heart Failure

Background: Subclinical cognitive impairment is prevalent in heart failure (HF); however, its role in important clinical outcomes, such as HF treatment adherence, is unclear. Given the complex polypharmacy in HF treatment, cognitive deficits may be important in predicting medication management. Thus, the objective of the current study was to examine the impact of cognitive function on medication adherence among community-dwelling patients with HF using objective assessments.

Methods and results: A prospective observational cohort design of 309 community-dwelling patients with HF (59.7% male, 68.7±9.7 years) and no history of dementia or neurological disease. Cognition was assessed using a neuropsychological battery at baseline. Medication adherence was objectively measured for 21 days using an electronic pillbox. Regression analyses tested whether attention, executive function, or memory predicted 21-day medication adherence. In unadjusted analyses, lower scores on all 3 cognitive domains predicted poorer medication adherence (β=0.52-85; P=0.001-0.009). After adjusting for demographic, clinical, and psychosocial variables, memory continued to predict medication adherence (β=0.51; P=0.008), whereas executive function (β=0.24; P=0.075) and attention were no longer a predictor (β=0.34; P=0.131).

Conclusions: Poorer cognitive function, especially in regard to memory, predicted reduced medication adherence among patients with HF and no history of dementia. This effect remained after adjustment for factors known to predict adherence, such as depressed mood, social support, and disease severity level. Future studies should examine the link from cognitive impairment and medication nonadherence to clinical outcomes (eg, hospitalization and mortality).

Clinical trial registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01461629.