Abstract 11742: A Single-pill Antihypertensive/lipid-lowering Regimen Improves Adherence to Treatment in General Japanese Patients

Abstract

Background: Nonadherence to treatment hinders successful management of chronic diseases, such as hypertension(HTN) and hypercholesterolemia(Hchol). Although adherence-related factors have been identified, their effects differ under different healthcare and social environments. Here, we investigated whether single-pill treatment, a fixed-dose combination drug to reduce pill burden, improves adherence and persistence in Japanese patients undergoing antihypertensive and statin therapy in a general clinical setting, marked by a super-aging society, universal health insurance system, and lopsided power balance between doctor and patient.

Methods: A retrospective longitudinal analysis of a general Japanese population was performed. Pharmacy claim data were used to identify HTN patients with Hchol who were treated with single-pill atorvastatin/amlodipine (SPAA) or with calcium channel blocker (CCB) and statin as 2 pills. Adherence, evaluated by proportion of days covered (PDC), and persistence to treatment were compared between the 2 regimens. Risk factors for nonadherence were also identified by multiple logistic regression analysis.

Results: In all, 5,478 patients were studied (3,652 on CCB+statin and 1,826 on SPAA; men, 41%; mean age, 69.8 ± 10.7 years). The mean PDC was significantly higher in the SPAA group compared with that in the CCB+statin group (P<0.001). The rate of nonadherence was 24.9% and 16.4% in the CCB+statin and SPAA groups, respectively (P < 0.001). In univariate analysis, younger patients and diabetes patients were less adherent, but adherence to SPAA was higher in these subpopulations. In multiple regression analysis, single pill (OR: 0.50, 95%CI: 0.43-0.59) and older age (OR:0.98, 95%CI:0.98-0.99) were positively associated with better adherence, while smaller hospital size (OR:1.23, 95%CI:1.16-1.42) and diabetes (OR:1.27, 95%CI:1.05-1.53) were negatively associated. Overall, within 26 weeks, 50.9% subjects receiving CCB+statin discontinued either or both pills, while 19.7% discontinued SPAA (P < 0.01).

Conclusion: SPAA treatment shows better adherence and persistence compared with the 2-pill regimen even in Japan, whose healthcare and social environment differ from those of Western countries.