Patient Adherence With Amlodipine, Lisinopril, or Valsartan Therapy in a Usual-Care Setting

OBJECTIVES: To compare the persistence and compliance in a usual-care setting with 3 drugs (amlodipine, lisinopril, or valsartan) from 3 different pharmaceutical classes.calcium-channel blocker, angiotensin-converting enzyme inhibitor, and angiotensin receptor blocker, respectively, commonly used to treat hypertension. METHODS: This retrospective observational study included a cohort of 142,945 continuously benefit-eligible patients from a pharmacy benefit manager drug claims database who began therapy with lisinopril, valsartan, or amlodipine. Concurrent use of other cardiovascular medications was assessed as a proxy for cardiovascular disease severity. Chronic Disease Score (CDS), derived from pharmacy claims data, was used to classify patient chronic disease burden as mild, moderate, or severe. Drug utilization measures included compliance, persistence, medication possession ratio (MPR), duration of therapy, and drug discontinuation. Multiple linear regression techniques were used to assess the impact of various predictor variables on study outcomes and to compare compliance among treatment groups, adjusted for age, gender, and CDS. RESULTS: The mean age of the study cohort was 63.1 years; 53% were female. Just over one half (51%, n=73,148) received amlodipine, 28% (n=40,238) received lisinopril, and 21% (n=29,669) received valsartan. Significantly more valsartan patients (63%) remained persistent on therapy at 12 months past the index date of the first prescription, compared with amlodipine (53%) and lisinopril (50%) patients (P less than 0.001). Both crude and adjusted compliance rates also were greatest for valsartan patients, reflected by an adjusted mean MPR of 75%, compared with 67% for amlodipine and 65% for lisinopril (P less than 0.0001, both comparisons). CONCLUSIONS: These results suggest that, in a usual-care setting, patients receiving valsartan (relative to amlodipine or lisinopril) appear to be more compliant and persistent with pharmacologic therapy, independent of patient chronic disease burden.