Abstract 11970: The Impact of First-Fill Discontinuations on Non-Adherence to Antihypertensive Therapy: An Observational Study
Background: Medication non-adherence is a barrier to the successful management of hypertension, but little is known about the impact that immediate discontinuations have on antihypertensive (AHT) non-adherence. The purpose of this study was to determine the proportion of new users of AHT medications who discontinue after only a single dispensation.
Methods: This retrospective cohort study utilized linked administrative data from Saskatchewan, Canada. Subjects were ≥40 years of age and had received a new AHT prescription between 1994 and 2002. The primary endpoint was the proportion of subjects who discontinued their AHT after the first dispensation (i.e. first-fill discontinuation). The proportion of non-adherence attributed to first fill discontinuations was then calculated. Multivariate logistic regression identified factors associated with first fill discontinuations.
Results: 52,039 subjects were included in the analyses. Mean age was 59.4 (SD 12.5) years, and 42% were male. Overall, 19.4% (10,081/52,039) subjects discontinued all AHT therapy after the first fill. A higher chronic disease score (adjusted OR 1.09, 95% CI 1.08-1.11) and antidepressant medication usage during the observation year (adjusted OR 1.17, 95% CI 1.09-1.26) was associated with an increased risk for first fill discontinuations. Older age, starting AHT therapy after 1994, frequent physician visits, or use of a statin, ASA, warfarin or antihyperglycemic drug during the observation year was associated with a lower risk for first fill discontinuations. First fill discontinuations accounted for 39.1% (10,081/25,812) of non-adherence at one year.
Conclusion: A substantial proportion of non-adherence to AHT medications is due to subjects who discontinue after only a single dispensation.
- © 2011 by American Heart Association, Inc.