Abstract
Background
Little is known about weekly variability in medication nonadherence both between and within persons.
Purpose
To characterize medication nonadherence across repeated, closely spaced occasions.
Methods
This prospective cohort study comprised four unannounced telephone assessment occasions, each separated by approximately 2 weeks. On each occasion, adult outpatients taking at least a single antihypertensive medication completed a measure of extent of, and reasons for, nonadherence.
Results
Two hundred and sixty-one participants completed 871 (83%) of 1,044 occasions. Nonadherence was reported on 152 (17.5%) of 871 occasions by 93 (36%) of 261 participants. The most commonly endorsed reasons for nonadherence were forgetting (39.5%), being busy (23.7%), and traveling (19.7%). Among 219 participants completing at least three occasions, 50% of the variability in extent of nonadherence was a result of within-person fluctuations, and 50% was a result of between-person differences.
Conclusion
Interventions to reduce nonadherence should be informed by variability in the extent of nonadherence and specific reasons for nonadherence.
Acknowledgments
We are grateful to the many individuals who participated in data collection, including Jamiyla Bolton, Tamika Brown, Jahdai Dawes, Terry Ervin, Leslie Gaillard, Kymeiria Ingram, and Cherisa Williams. We are also grateful to Jamiyla Bolton and Jennifer Lindquist for study database development and maintenance. This study was funded by a grant from the National Institute on Aging (R21 AG035233) to CIV and WSY. HAK was supported by a postdoctoral fellowship from the Department of Veterans Affairs, Office of Academic Affiliations, Health Services Research and Development (TPP 21-020). MLM was supported by a Research Career Scientist award from the Department of Veterans Affairs (RCS 10-391). The views expressed in this article are those of the authors and do not necessarily reflect the position or policy of the Department of Veterans Affairs or the United States government.
Disclosure
The authors report no conflicts of interest in this work.