Antihypertensive Pill Burden and Patient Adherence

New York—Hypertension causes 7 million premature deaths each year. More than 40% of patients with hypertension remain untreated, while two-thirds of patients treated do not have adequately controlled blood pressure (BP).

Previous studies have indicated that monotherapy with 1 antihypertensive medication class is inadequate in getting some patients to targeted BP goals. Single-pill, fixed-dose combination therapies simplify drug regimens and may improve medication adherence.

L. Xie and colleagues conducted a study to compare the adherence and persistence to single-, double-, and triple-pill regimens among patients treated with 3 antihypertensive medications in a US clinical practice setting. This study was presented at the ASH meeting during a poster session titled Impact of Antihypertensive Pill Burden on Patient Adherence.

This retrospective analysis used the Truven Health Analytics MarketScan^® claims database to identify patients prescribed single-, double-, or triple-pill antihypertensive combination therapy with either olmesartan medoxomil (OLM) or valsartan (VAL), plus amlodipine besylate (AML) and hydrochlorothiazide (HCTZ). Data from January 1, 2010, through September 30, 2012, were analyzed.
Patients were eligible for study inclusion if they were ≥18 years of age at the index date, had continuous medical and pharmacy benefits for at least 6 months pre-index and at least 12 months post-index, had ≥1 hypertension diagnosis code during the study period, and had no pharmacy claims for the index regimen in the baseline period; however, partial components were allowed. Patients were excluded if there was evidence of heart failure, left ventricular hypertrophy, or nephropathy at any time during the study.

The single-pill cohort received OLM/AML/HCTZ or VAL/AML/HCTZ. The double-pill cohort received OLM/AML+HCTZ, VAL/AML+HCTZ, OLM/HCTZ+AML, or VAL/HCTZ+AML. The triple-pill cohort received OLM+AML+HCTZ or VAL+AML+HCTZ. Adherence, discontinuation, and time to discontinuation were all evaluated. A total of 8516 patients were evaluated for single-pill therapy, 7842 patients for double-pill therapy, and 1107 patients for triple-pill therapy.

Single-pill cohort patients were younger, more likely to be male, and had fewer comorbid conditions than patients prescribed the double- or triple-pill therapy.

Patients receiving triple-pill drug regimens were more likely to discontinue medication: 21.5% of triple-pill patients discontinued medication, 18.86% of double-pill patients discontinued, and 11.45% of single-pill patients discontinued. The median time to discontinuation was lowest for patients in the triple-pill cohort: 117 days to discontinuation for the triple-pill cohort, 134 days for the double-pill cohort, and 148 days for the single-pill cohort. Thus, greater pill burden was significantly associated with decreased odds of medication adherence and a greater likelihood of medication discontinuation.
The study’s authors noted limitations. Adherence was measured based on prescription fills and proportion of days covered; however, it cannot be verified that patients took their medication as prescribed. Also, the claims data were collected for the purpose of payment rather than research.
The researchers concluded that a greater pill burden was directly and significantly associated with decreased adherence and persistence with antihypertensive therapies in real-world settings.

Fixed-dose combination therapy may help patients adhere to treatment, which can result in improved clinical outcomes.—Kerri Fitzgerald