Choice of initial antihypertensive drugs and persistence of drug use—a 4-year follow-up of 78,453 incident users

Abstract

To investigate patterns of initial drug therapy for the treatment of hypertension and to evaluate treatment persistence and change of treatment during a 4-year period in patients receiving thiazides (TZs) and/or angiotensin II-receptor blockers (ARBs) as first-line treatment. All initial users of antihypertensive drugs in 2005 and 2009 registered in the Norwegian Prescription Database were included. Treatment on five index dates at 1-year intervals was recorded. A patient was considered to be under treatment on an index date if a drug had been dispensed within the previous 180 days and to have maintained treatment persistence if he/she was on any antihypertensive treatment on the index date and all previous index dates. Among 78,453 new users of antihypertensives in 2005, women started more often with TZs than men (30 vs. 25 %) and less often with ARBs (22 vs. 25 %). In men, the hazard of non-persistence with antihypertensive treatment was significantly lower among initial ARB users than among TZ users (hazard ratio 0.87, 95 % confidence interval 0.81-0.94); in women no significant difference was found. After 4 years, 49 % of the men and 51 % of the women who had started with plain TZs were still using TZs, whereas 65 % of the male ARB users and 60 % of the female ARB users were still using ARBs. TZs and ARBs were the most widely used first-line antihypertensives. Among the men enrolled in the study, ARB users had a somewhat better persistence with antihypertensive treatment than TZ users. Among both genders, continuation on ARBs was more common than continuation on TZs.