Executive Functioning and Adherence to Antihypertensive Medications Among a Sample of Older Adults

Objective: Consistent medication adherence is critical for the effective management of hypertension among the elderly. Executive functioning (EF), higher-order cognitive abilities that include set-shifting, information updating, and inhibition, have been associated with medication adherence among other populations, but the role of these processes in adherence to medications in older adults with hypertension is unknown. A conceptual model of the ways in which specific executive processes could impact adherence is presented, and specific executive processes and broad EF were examined as predictors of adherence to antihypertensive medication over a 3-month study of hypertension and cognition in the elderly. Method: 76 adults with hypertension over age 75 completed baseline neuropsychological testing, including multiple tests of EF: Trail Making Test, Part B, the Wechsler Adult Intelligence Scales-Fourth Edition Digit Span Backwards task, the Stroop Color-Word Test, and phonemic/letter fluency and semantic/category fluency tasks. Medication adherence was measured by pill count (proportion of prescribed pills returned). Results: Participants in the study were largely adherent, and missed an average of just 6.32% of their doses of antihypertensive medication in the three months following cognitive testing (SD = 10.35). Composite EF scores were significantly predictive of better adherence to antihypertensive medications in the three months following baseline neuropsychological testing (Exp(b) = 0.926; 95% CI: 0.870–0.985; p = 0.014), as were performances on a measure of information updating/monitoring (difference between Digits Backward and Digits Forward scores: Exp(b) = 0.907; 95% CI: 0.828–0.994; p = 0.037) and a measure of inhibition (Stroop Interference scores: Exp(b) = 0.960; 95% CI: 0.930–0.991; p = 0.013). Other tests of EF were not significantly associated with adherence. Conclusion: These findings lend partial support to the proposed conceptual model and suggest that screening for deficits in broad EF, and information updating and inhibitory control specifically, may help to identify and perhaps intervene with patients at risk for suboptimal antihypertensive adherence