Good adherence to therapy with statins reduces the risk of adverse clinical outcomes even among very elderly. Evidence from an Italian real-life investigation

Abstract

Aim: To assess whether in individuals aged 80years or older adherence to statins is accompanied by a reduced risk of all-cause mortality and major cardiovascular events.

Methods: A nested case-control study was carried out on a cohort of patients aged 80years or older (very elderly individuals), who were under treatment with statins between 2008 and 2009, using the database available for all citizenship (about 10 million) of Lombardy (Italy). Cases were the cohort members who experienced death or hospitalization for stroke, myocardial infarction or heart failure from the initial prescription until 2012. Up to five controls were randomly selected for each case. Logistic regression was used to model the outcome risk associated with the adherence to therapy with statins. Two younger patient cohorts aged 60 to 69years and 70 to 79years were taken for comparison. A set of sensitivity analyses was performed in order to account for sources of systematic uncertainty.

Results: Among very elderly individuals, those who had high adherence to statins showed significant risk reductions of death (56%; 95% Confidence Interval, 54% to 59%), myocardial infarction (15%; 5% to 24%), stroke (13%; 0% to 24%) and heart failure (30%; 23% to 36%) with respect to those at very low adherence. Adherence-related risk reductions were only slightly better for younger cohort members.

Conclusions: Adherence to therapy with statins reduced the risk of both death and cardiovascular morbidity in patients aged 80years or older.

Keywords: Adherence; Cardiovascular outcomes; Elderly; Healthcare utilization database; Mortality; Record linkage; Statins; Very elderly.