Patient Pill Organization Strategies and Adherence Measured in a Cross-Sectional Study of Hypertension

Background: The strategies patients use to organize medications (eg, pill dispenser) may be reflected in adherence measured at follow-up. We studied whether medication organization strategies patients use at home are associated with adherence measured using pharmacy-fills, self-report, and pill counts.Design: Secondary analysis of data from a prospective randomized clinical trial.Setting: Eleven US safety-net and community primary care clinics. Patients: Of the 960 enrolled self-identified non-Hispanic Black and White patients prescribed antihypertensive medications, 731 patients reported pill organization strategies and were included. Variable: Patients were asked if they use any of the following medication organization strategies: finish previous refills first; use a pill dispenser; combine same prescriptions; or combine dissimilar prescriptions.Outcomes: Adherence to antihypertensive medications using pill counts (range, 0.0-1.0% of the days covered), pharmacy-fill (proportion of days covered >90%), and self-report (adherent/non-adherent).Results: Of the 731 participants, 38.3% were men, 51.7% were age >= 65, 52.9% self-identified as Black or African American. Of the strategies studied, 51.7% finished previous refills first, 46.5% used a pill dispenser, 38.2% combined same prescriptions and 6.0% combined dissimilar prescriptions. Median (IQR) pill count adherence was 0.65 (0.40-0.87), pharmacy-fill adherence was 75.7%, and self-reported adherence was 63.2%. Those who combined same prescriptions had significantly lower measured pill count adherence than those who did not (0.56 (0.26-0.82) vs 0.70 (0.46-0.90), p<0.01) with no significant difference in pharmacy-fill (78.1% vs 74%, p=0.22) or self-reported adherence (63.0% vs 63.3%, p=0.93).Conclusion: Self-reported medication organization strategies were common. Combining same prescriptions was associated with lower adherence as measured using pill counts but not pharmacy-fills or self-report. Clinicians and researchers should identify the pill organization strategies used by their patients to understand how these strategies may influence measures of patient adherence.Trial Registration: ClinicalTrials.gov NCT03028597; https://clinicaltrials.gov/ct2/show/NCT03028597 (Archived by WebCite at http://www.webcitation.org/72vcZMzAB).

Automated summary

This study examined the association between medication organization strategies at home and medication adherence. It found that combining same prescriptions was associated with lower adherence as measured by pill counts. Understanding patients' medication organization strategies is important for clinicians and researchers in assessing patient adherence.