Do statins reduce hospital admissions for cardiovascular diseases?

Managing cardiovascular risk is a vital concern for healthcare systems. Statins are lipid-lowering drugs used to prevent adverse cardiovascular events. Using an instrumental variables approach, this study investigates the causal effect of statin use on hospitalisations for cardiovascular disease, moving beyond the correlational evidence from existing ecological studies. We identify exogenous variation in statin consumption unrelated to unobserved cardiovascular risk by leveraging observed variation in prescribing patterns and physicians’ preferences. We focus on the Emilia-Romagna region (Italy) from 2010 to 2019, using district-level longitudinal data. We consider two study populations to measure hospitalisations among individuals aged 50 and over: firstly, the general population living in the region; secondly, those on statin therapy (statin users). Our findings indicate that statins significantly reduce hospitalisations for cardiovascular disease, with effects differing by diagnosis, admission type, and gender. Additionally, when analysing two aspects of statin use—coverage and treatment intensity—we find that coverage appears to be more influential across different types of cardiovascular events. We also find that the reduction in the risk of adverse episodes predominantly involves medium-to low-risk groups, rather than individuals who have already experienced major cardiovascular events. From a policy perspective, our findings emphasise the importance of tailoring prevention measures to medium- and low-risk groups and the effectiveness of prevention strategies based on prescription drugs, beyond individual risk assessment.