Abstract 1581: Patient Compliance With Single Pill, Dual and Triple Antihypertensive Combinations
Patient adherence is essential to achieve blood pressure control and favorable patient outcomes. Our objective was to compare the compliance of patients taking a single pill combination (SPC) of valsartan+amlodipine versus dual and triple therapy with an angiotensin receptor blocker (ARB) + a dihydropyridine calcium channel blocker (CCB) with or without hydrochlorothiazide (HCTZ). A retrospective cohort study of pharmacy and medical claims (Medstat MarketScan®) was conducted. Patients included in the study were continuously insured from January 2007 to September 2008, were ≥18 years of age with a hypertension medical claim and with 2 or more fills for valsartan+amlodipine (“SPC”), an ARB+CCB free combination (“dual”) or an ARB+CCB+HCTZ free combination (“triple”) concomitantly between July 2007 and September 2008. “Concomitant” was defined as prescriptions filled within 30 days of each other. All patients were initiating therapy, meaning they had no prescriptions for these agents 6 months prior to the first fill. Compliance was measured using the medication possession ratio (MPR), defined as the percent of days’ supply between the initial and last fill dates. Descriptive statistics and 95% Bootstrap confidence intervals were calculated using SAS software. The study population consisted of 29,627 individuals (11,588 SPC, 17,868 dual, 171 triple) with mean age 61.7 years and 49% female. The top three prevalent comorbid conditions were ischemic heart disease (18.2%), cerebrovascular disease (11.3%) and diabetes (4.0%). Mean compliance (95% CI) was 0.85 (0.84, 0.85), 0.63 (0.63, 0.64), and 0.54 (0.51, 0.58) for SPC, dual and triple, respectively. Patients taking single pill combinations were significantly more compliant than patients taking dual and triple antihypertensive therapy. The findings support existing evidence suggesting a negative impact of pill burden on compliance and the value of single pill combinations.