Medication Adherence in Older Patients With Dementia: A Systematic Literature Review

Medication non-adherence is a significant health problem. There are numerous methods for measuring adherence, but no single method performs well on all criteria. The purpose of this systematic review is to (i) identify self-report medication adherence scales that have been correlated with comparison measures of medication-taking behaviour, (ii) assess how these scales measure adherence and (iii) explore how these adherence scales have been validated.

Cardiovascular diseases (CVD) represent a heavy economic burden on individuals, health services, and society. Low adherence to antihypertensive (AH) agents is acknowledged as a major contributor to the lack of blood pressure control, and may have a significant impact on clinical outcomes and healthcare costs. To evaluate the impact of low adherence to AH agents on cardiovascular outcomes and hospitalization costs. A cohort of 59,647 patients with essential hypertension was reconstructed from the Régie de l'assurance maladie du Québec and Med-Echo databases. Subjects included were between 45 and 85 years of age, without any evidence for symptomatic CVD, newly treated with AH agents between 1999 and 2002 and followed-up for a 3-year period. Adherence to AH agents was categorized as >or=80% or <80%. The adjusted odds ratio (OR) for CVD events between the 2 adherence groups was estimated using a polytomous logistic analysis. A 2-part model was applied for hospitalization costs. Patients with low adherence were more likely to have coronary disease (OR, 1.07; 95% confidence interval [CI], 1.00-1.13), cerebrovascular disease (OR, 1.13; 95% CI, 1.03-1.25), and chronic heart failure (OR, 1.42; 95% CI, 1.27-1.58) within the 3-year follow-up period. Among hospitalized patients, low adherence to AH therapy was associated with increased costs by approximately $3574 (95% CI, $2897-$4249) per person within a 3-year period. Low adherence to AH agents is correlated with a higher risk of vascular events, hospitalization, and greater healthcare costs. An increased level of adherence to AH agents should provide a better health status for individuals and a net economic gain.

Cognitive impairment challenges the ability to adhere to the complex medication regimens needed to treat multiple medical problems in older adults.