Income differences in the type of antihypertensive medicines used in ambulatory settings in Finland: a register-based study.

ABSTRACT

PURPOSE: The objective of this study was to explore income differences in the prevalence of moderate-to-severe hypertension, and among patients, in the use and costs of medicines. METHODS: Personal income was used to classify ≥25-year-old population in quintiles (QI-QV). Patients (N = 497,560) with moderate-to-severe hypertension were identified using special refund entitlements. Medicine use and costs derived from prescription register. Direct standardisation and multivariate regression were used to adjust for demographics and comorbidities. RESULTS: Low income was associated with higher prevalence of moderate-to-severe hypertension (overall 13%). After adjusting for age, gender, residence, diabetes and coronary heart disease, nearly all patients purchased at least one antihypertensive medicine (93 vs. 96% in QI and QV). Differences in the purchased quantities were small (mean estimates 1028 vs. 1054 defined daily doses (DDDs)/patient/year in QIV and QI). High-income patients were more likely to use angiotensin receptor blockers (37 vs. 54% in QI and QV). Low-income patients were more likely to use beta-blockers (59 vs. 49%, respectively) and ACE inhibitors (35 vs. 28%, respectively). Higher income was associated with higher annual out-of-pocket costs (mean €66 vs. €71 in QI and QV) and reimbursements (€144 vs. €163, respectively). CONCLUSIONS: Use of more expensive medicines contributed to higher costs among patients with higher incomes.