Adherence to statin therapy and patients' cardiovascular risk: a pharmacoepidemiological study in Italy

AIM: To evaluate the pattern of use of statins in the Emilia Romagna Region, with a focus on the therapeutic regimens and the patient's risk profile as predictors of adherence to therapy. METHODS: All patients from Emilia Romagna (4,027,275 inhabitants) receiving statin prescriptions in January-February 2005 were selected and observed for 12 months in terms of their statin regimen and use of other drugs for cardiovascular risk prevention. Previous hospital admissions for major cardiovascular events were also obtained. Adherence to statins was evaluated in terms of coverage (covered: >or=300 tablets/year). The relationship between coverage and risk profile (age, sex, other cardiovascular drugs, previous cardiovascular events and choice of drugs/dosages) was analysed by multivariate logistic regression. RESULTS: Among the 137,217 patients receiving at least one prescription in the observation period, the rate of coverage was 46%. Coverage was statistically higher in patients with a previous hospital admission (secondary prevention) [Odds ratio (OR) 1.19; 95% confidence interval (95% CI) 1.16, 1.22], in those concomitantly treated with three to four different cardiovascular drugs (OR 2.77; 95% CI 2.66, 2.89). The coverage was also statistically higher in patients aged 50-69 years (OR 1.14; 95% CI 1.08, 1.20) and among males (OR 1.21; 95% CI 1.18, 1.23). CONCLUSIONS: Less than half of patients receiving statin therapy took their medication daily, with a coverage only slightly higher in patients at higher cardiovascular risk. Three-quarters of the patients received statin therapy in primary prevention, whereas the benefits of statins are documented mostly for patients in secondary prevention. These findings strengthen the need to sensitise physicians and patients to the correct use of statins.