TREATMENT STRATEGIES AND ADHERENCE TO THE TRIPLE COMBINATION OF AN ANGIOTENSIN-CONVERTING ENZYME INHIBITOR, A CALCIUM-CHANNEL BLOCKER, AND A DIURETIC

Abstract

Objective: To compare adherence to antihypertensive treatment between patients prescribed the perindopril/amlodipine/indapamide single-pill combination (SPC) vs the combination of an angiotensin-converting enzyme inhibitor (ACEI), a calcium-channel blocker (CCB), and a diuretic (D) as a SPC of two drugs plus the third drug separately. Design and method: Patients aged > = 40 years who received a prescription of perindopril/amlodipine/indapamide SPC during 2015-2018 were identified and the date of the first prescription was defined as the index date. For each patient prescribed the SPC, a subject who started ACEI/CCB/D treatment as a two-drug SPC plus a third drug separately (i.e. 2 pills) at the index date was identified. Adherence to the triple combination was assessed over the year after the index date as the proportion of the follow-up days covered (PDC) by prescription. The primary aim was to compare the odds of being highly adherent to the drug therapy (PDC>75%) between groups. Secondary aims were to compare (i) the risk of cardiovascular hospitalizations and (ii) the costs of cardiovascular health services (hospitalizations, drugs, and outpatient services). Log-binomial regression models were fitted to estimate the risk ratio, and its 95% confidence interval, of treatment adherence in relation to the drug strategy. A Cox model and a linear regression model were fitted to compare the risk of cardiovascular hospitalizations and mean of healthcare costs, respectively, between groups. Results: 28,210 patients prescribed the perindopril/amlodipine/indapamide SPC were identified and matched to 28,210 patients prescribed ACEI/CCB/D in two pills. Compared with patients under two-pill combination, those who were treated with the SPC had a higher propensity to be highly adherent to the triple combination (2.38, 2.32 – 2.44). Three-drug SPC users had a 13% lower risk of cardiovascular hospitalizations and a € 64 lower costs for cardiovascular healthcare services (p < 0.001) due to reduced hospitalization costs (€ 59). Conclusions: In a real-life setting, patients who were prescribed the perindopril/amlodipine/indapamide SPC exhibited more frequently a good adherence to antihypertensive treatment than those prescribed a combination of ACEI/CCB/D as a two drugs SPC plus a third drug separately.