Adherence to Triple-Free-Drug Combination Therapies Among Patients With Cardiovascular Disease

Combination therapies are often needed to modify the concomitant risk factors for cardiovascular disease. Nonadherence to cardiovascular medications is a relevant concern, especially in polytherapy. We conducted a population-based, cohort study with the aim of quantifying the level of adherence and its related determinants in patients exposed to free 3-drug combination therapies, namely concurrent use of angiotensin-converting-enzyme inhibitor (ACEi), calcium channel blocker (CCB), and statin or of ACEi, statin, and low-dose aspirin. Within Health Search Database, we selected a cohort of adult patients concurrently prescribed with ACEi, CCB, and statin, as well as those prescribed with ACEi, statin and low-dose aspirin, from the January 1, 2002 to the December 31, 2014. Adherent patients were concurrent users of triple free pill regimen with a proportion of days covered ≥80% during 1-year follow-up; demographics and clinical determinants of 1-year adherence were identified by multivariate logistic regression. We found that more than half of patients prescribed with triple free drug combination therapy with ACEi plus CCB plus statin or ACEi plus statin plus low-dose aspirin, were found to be nonadherent to these treatments. Males and patients at high/very-high cardiovascular risk were more likely to be adherent, whereas depression and atrial fibrillation were associated with nonadherence. Our findings indicate that sex, cardiovascular risk, presence of atrial fibrillation, and depression can influence adherence to polytherapy. In conclusion, given that patients suffering from multiple cardiovascular risk factors are at higher risk of fatal events, strategies are needed to improve medication adherence to combination therapies.