OBJECTIVES: To assess whether single-pill amlodipine besylate/atorvastatin calcium (SPAA) use achieves greater adherence than other, 2-pill calcium channel blocker (CCB) + statin regimens stratified by brand/generic status using records of drug benefits managed by a large U.S. Pharmacy Benefit Management company. METHODS: Patients (N=3,561) newly initiated on either a CCB or a statin within 30 days of each other were followed for 1 year. The 2-pill CCB + statin group (including patients on amlodipine + atorvastatin) was sub-divided by brand/generic status. Adherence (proportion of days covered [PDC]) was based on the days that both antihypertensive and lipid-lowering drugs were supplied, and was considered achieved if PDC was ³80%. Persistence was defined as the number of days on therapies until the first 30-day gap. Propensity-score weighted logistic regression and proportional hazard models were used to adjust for demographics and key baseline pharmacy utilization variables including copay. RESULTS: At baseline, mean age was 63 years, 52% were female, 11% utilized coronary vasodilators, 30% utilized anti-diabetics; mean number of other baseline medications was 8. Baseline characteristics varied between cohorts. The percentages of patients achieving PDC³80% were: SPAA 63.9%, Branded CCB + Branded statin (BB) 38.9%, Branded CCB + Generic statin (BG) 37.8% and Generic CCB + Generic statin (GG) 32.1%. SPAA patients were three times as likely to achieve adherence versus BB (OR=3.39; CI: 3.06-3.75; P<0.0001) and BG (OR=3.14; CI: 2.84-3.47; P<0.0001); and more than twice as likely versus GG (OR=2.77; CI: 2.50-3.06; P<0.0001). SPAA patients were less likely to discontinue therapies versus BB (HR=0.52; CI: 0.49-0.56; P<0.0001), BG (HR=0.52; CI: 0.49-0.55; P<0.0001), and GG (HR=0.59; CI: 0.55-0.63; P<0.0001). CONCLUSION: In this nationally representative, insured population, patients receiving the single-pill were more likely to achieve adherence versus 2-pill CCB + statin regimens even if a lower-cost generic was used.