Risk factors for medication nonadherence in older adults with cognitive impairment who live alone

The aim of this study was to prospectively examine the influence of cognitive, medical, behavioral, and social risk factors on medication nonadherence in community-dwelling older adults with cognitive impairment.

A sample of 339 elderly participants with cognitive impairment, who lived alone and took at least one medication, underwent baseline assessment which included the five subscales of the Dementia Rating Scale (DRS), number of medications, retrospective medication nonadherence, amount of formal and informal assistance, functional impairment, depression, perception of social resources, comorbidity, and alcohol consumption. The outcome was medication nonadherence during the 12-month prospective period as reported by the participants' primary care physicians and caregivers at three-month intervals.

Fifty-nine participants (17.4%) had, at least, one report of medication nonadherence. Logistic regression analyses indicated for every point increase on the DRS Conceptualization subscale (OR = 1.14; 95% CI = 1.02-1.27), there was a 14% increase in the odds of nonadherence. For every point increase on the DRS Memory subscale (OR = 0.89; 95% CI = 0.81-0.97) and DRS Initiation/Perseveration subscale (OR = 0.93; 95% CI = 0.87-1.00), there was an 11% decrease and 7% decrease in the odds, respectively. Having at least one previous occurrence of medication nonadherence (OR = 2.61; 95% CI = 1.18-5.62) and taking at least four medications (OR = 2.58; 95% CI = 1.31-5.29), both increased the odds by over 2.5-fold.

Our unique finding that better conceptualization predicted nonadherence has important implications for healthcare providers' approaches to improve adherence in older adults with cognitive impairment. Replication in future studies is warranted.