A medication adherence and persistence comparison of hypertensive patients treated with single-, double- and triple-pill combination therapy

Abstract

Objective:

Fixed-dose combination therapy reduces pill burden and may, therefore, improve medication adherence and health outcomes. This study compared adherence to and persistence with single-, double-, and triple-pill treatment regimens among hypertensive patients in a US clinical practice setting.

Methods:

Adults with hypertension treated with three anti-hypertensive medications were identified. Index date was the first occurrence of a single-, double-, or triple-pill regimen with olmesartan or valsartan plus amlodipine and hydrochlorothiazide from July 2010 to September 2011. Patients were followed for 12 months to assess adherence (proportion of days covered [PDC] ≥ 80%) and time to discontinuation (medication gap ≥60 days) of the index regimen. Multivariate regression models were used to compare adjusted outcomes.

Results:

The number of prescribed pills in the index regimen was monotonically related to adherence with 55.3%, 40.4% and 32.6% of patients having PDC ≥80% in the single-, double- and triple-pill cohorts, respectively. In adjusted analysis, patients in the double- (odds ratio [OR]: 0.45; 95% confidence interval [CI]: 0.42–0.48) and triple-pill (OR: 0.26; 95% CI: 0.22–0.30) cohorts were less likely to be adherent to their index regimens than those in the single-pill cohort. Double-pill (hazard ratio [HR]: 1.89; 95% CI: 1.74–2.06) and triple-pill patients (HR: 2.49; 95% CI: 2.14–2.88) were more likely to discontinue treatment than single-pill patients.

Conclusions:

Greater pill burden was directly and significantly associated with decreased adherence and persistence with antihypertensive therapies in real-practice settings. Use of fixed-dose combinations that reduce pill burden could help patients to continue treatment and may result in improved clinical outcomes. Typical of observational studies, the potential for residual confounding of adherence estimates remains due to lack of randomization of treatment groups.

Keywords::

• Fixed-dose combination therapy
• Hypertension
• Medication adherence
• Medication persistence

Transparency

Declaration of funding

This study was funded by Daiichi Sankyo Inc.

Declaration of financial/other relationships

L.X. and O.B. have disclosed that they are employees of STATinMED Research, a paid consultant to Daiichi Sankyo Inc. F.F.-T. has disclosed that she is an employee of Daiichi Sankyo Inc. and has financial interest in Daiichi Sankyo Inc. and other pharmaceutical companies. E.M. has disclosed that she is an employee of Daiichi Sankyo Inc.

CMRO peer reviewer 1 has disclosed that he is on the speakers’ bureau of Novartis, Berlin Chemie, and UCB. CMRO peer reviewer 2 has no relevant financial or other relationships to disclose.

Acknowledgments

Statistical analysis support was provided by M. Furaha Kariburyo MPH of STATinMED Research. Statistical programming was conducted by Yuexi Wang MS of STATinMED Research. Editorial support was provided by Elizabeth Moran of STATinMED Research.