Date Presented 4/1/2017
Poor medication adherence is a strong predictor of readmissions and declines in health and function. Unfortunately, current tools offer poor clinical utility for adults with disabilities in the community. Measurement methods will be reviewed and implications for research and practice will be discussed.
Primary Author and Speaker: Jaclyn K. Schwartz
PURPOSE: Approximately half of consumers fail to take their medications, resulting in impairments to health and function. It is imperative for health care professionals to accurately measure medication adherence to understand which clients require adherence intervention. Researchers have identified five ways to measure medication adherence: pill counts, daily monitoring, pharmacy records, self-report questionnaires, and performance-based assessments (Cooper, Hall, Penland, Krueger, & May, 2009; Elliott & Marriott, 2009; Vik, Maxwell, & Hogan, 2004). Most adherence assessments were developed for research purposes. Little information describes the clinical utility of the various methods of assessment. The purpose of this study was to understand the clinical utility and validity of each of the established methods of measurement for a clinically relevant sample of people with chronic health conditions.
DESIGN: We used an exploratory convergent parallel mixed-methods approach. Researchers evaluated medication adherence using pill counts, diaries, a questionnaire, and a performance-based test. Then researchers interviewed participants about their medication routines. To be included in the study, participants were required to be community-dwelling adults diagnosed with a chronic health condition with a regimen of five or more medications a day.
METHOD: Nineteen adults completed the 2-wk study. The research team met participants in their homes or in the lab (at the participant’s discretion). Researchers administered the adherence assessments, conducted the interview, and instructed participants on keeping a 2-wk medication diary. Descriptive statistics were used to identify medication adherence for each of the adherence assessments. Pearson’s correlation coefficients were used to describe the relationship between measures of adherence.
RESULTS: Participants in the study consumed an average of 10 (SD = 3.48) medications a day with a range of 5–26 medications. Participants filled their prescription at an average of one pharmacy but as many as three pharmacies, and many participants reported using automatic refills. Participants scored an average of 4.19 of 8 (SD = 1.4) on a medication adherence screener. Participants completed the performance-based test in an average of 4.89 min (SD = 1.54) with an average of 0.8 mistakes (SD = 3.09). Three participants required assistance in manipulating medication containers. The medication diary revealed an average medication adherence rate of 93.66% (SD = 17.13). All participants engaged in behaviors that limited the accuracy of pill counts, such as combining old and new medications. Pearson’s correlation coefficients ranged from 0.68 to .466.
CONCLUSION: Accurate measurement of medication adherence is essential to ensuring positive client health and function. Unfortunately, no one method for measuring medication adherence is feasible for daily clinical use. Logistical barriers prevent use and accuracy of pharmacy fill records, pill counts, and medication diaries. Correlation analyses presented, at best, a fair degree of relationship between measurement approaches, indicating that they are measuring different constructs. Occupational therapy practitioners bring a unique skill set to measuring occupational performance. Occupational therapy researchers should use their expertise in measuring occupational performance to develop new valid and clinically useful tools to measure medication adherence.
References
Cooper, J., Hall, L., Penland, A., Krueger, A., & May, J. (2009). Measuring medication adherence. Population Health Management, 12, 25–30. https://doi.org/10.1089/pop.2008.0031
Elliott, R. A., & Marriott, J. L. (2009). Standardized assessment of patients’ capacity to manage medications: A systematic review of published instruments. BMC Geriatrics, 9, 27. https://doi.org/10.1186/1471-2318-9-27
Vik, S. A., Maxwell, C. J., & Hogan, D. B. (2004). Measurement, correlates, and health outcomes of medication adherence among seniors. Annals of Pharmacotherapy, 38, 303–312. http://doi.org/10.1345/aph.1D252
Zartman, A. L., Hilsabeck, R. C., Guarnaccia, C. A., & Houtz, A. (2013). The Pillbox Test: An ecological measure of executive functioning and estimate of medication management abilities. Archives of Clinical Neuropsychology, 28, 307–319. https://doi.org/10.1093/arclin/act014
