Fixed versus free combinations of antihypertensive drugs: Analyses of real-world data of persistence with therapy in Italy

Abstract

Purpose: To analyse the pattern of use and cost of antihypertensive drugs in new users in an Italian population, and explore the patient/treatment factors associated with the risk of therapy discontinuation. Patients and methods: In this retrospective study, information was collected from a population-based electronic primary-care database. Persistence with medication use 1 year from therapy initiation was evaluated for each user using the gap method. Each new user was classified according to his/her pattern of use as: “continuer”, “discontinuer” “switching” or “add-on”. A Cox regression model was used to analyse the factors influencing therapy discontinuation. Primary-care costs comprised specialists’ visits, diagnostic procedures and pharmacologic therapies. Results: Among 14,999 subjects included in persistence analyses, 55.1% of cases initially started on monotherapy were classified as discontinuers vs 36.5% of cases taking combination therapy (42.3% vs 32.7%, respectively, for free and fixed combinations, P < 0.01). Old age, high cardiovascular risk and being in receipt of fixed-combination therapy were associated with greater persistence. Overall, the primary-care cost/person/year of hypertension management was ~€95.3 (IQR, 144.9). The monotherapy cost was €88 per patient (IQR, 132.9), and that for combination therapy was €151±148.3. The median cost/patient with a fixed combination was lower than that for a free combination (€98.4 (IQR, 155.3) and €154.9 (IQR, 182.6), respectively). Conclusion: The initial type of therapy prescribed influences persistence. Prescribing fixed combinations might be a good choice as initial therapy.