RESUMO
OBJECTIVE: Drug non-adherence in primary preventive cardiovascular therapy is one of the most important modifiable drivers of cardiovascular events. The effect of deductibles in healthcare cost-sharing plans (the amount that has to be paid for healthcare services before the insurance company starts to pay) on such non-adherence in a European setting is unknown. Therefore, we estimated the association between deductibles and the adherence to primary preventive antihypertensive and antihyperlipidemic medication. METHODS: Using the claims database of Menzis Health Insurer in the Netherlands, we applied ordered beta regression mixed modelling to estimate the association between deductibles and adherence taking several demographic and social-economic factors, repeated measurements and within-patient variation into account. RESULTS: All in all, 106,316 patients starting primary preventive antihypertensive or antihyperlipidemic monotherapy were eligible for analysis. At index date, mean age of the study population was 58 years and 52% were male. Reaching the deductible limit and no need to pay for medication anymore increased the adherence [relative adherence ratio (RAR) 1.03, 95% confidence interval (95% CI): 1.00-1.05] for antihyperlipidemic therapy and 1.02 (95% CI: 1.00-1.04) for antihypertensive therapy. A larger deductible amount decreases the adherence of antihyperlipidemic and antihypertensive therapy (RAR 0.83; 95% CI: 0.69-1.00 and RAR 0.85, 95% CI: 0.74-0.98, respectively). CONCLUSION: Independent of other risk factors for non-adherence, presence of deductibles in health insurance is associated with a small negative effect on the adherence to both primary preventive antihypertensive as well as antihyperlipidemic therapy. Further study is needed on the potential health-economic consequences.
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We aim to identify risk factors of major adverse cardio-cerebrovascular events (MACCE) using a proxy of drug treatment for a MACCE after the start of statin therapy in the primary cardiovascular prevention group, taking drug dose, persistency and adherence into account. We conducted a retrospective inception cohort study using data from the University of Groningen prescription database IADB.nl, covering patients in the Northern part of the Netherlands. We identified adult starters on primary preventive statin therapy as patients without any statin or cardiovascular drug prescription in the two years before the first statin dispensing and used a weighted Cox proportional hazard model to estimate hazard ratios (HR) with their 95 % confidence intervals (95 %CI). Among 39,487 primary preventive statin starters, 23% received drug treatment for a MACCE within a median follow-up period of four years. Increasing age, male gender and presence of diabetes drug treatment were significantly associated with the outcome (HR: 1.03; 95 %CI: 1.02-1.04; HR: 1.27; 95 %CI: 1.12-1.44 and HR: 1.39; 95 %CI: 1.24-1.56, respectively). If patients remained statin therapy persistent, adherence was no longer associated with drug treatment for a MACCE. In 23 % of the statin therapy initiators, incident drug treatment for a MACCE occurred with a median of four years. To reduce event rates in this group, older patients, males and diabetes patients should be closely monitored. Non-adherence in the early stage of treatment should be avoided to prevent non-persistence.
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Background: Multiple studies and meta-analyses examined the role of traditional risk factors for cardiovascular events in statin treatment-naive patients. Nowadays, millions receive such therapy for the primary prevention of cardiovascular events (CVE). Objective: CVEs still occur in patients on primary preventive statin therapy. Therefore, further risk stratification within these patients is urgently needed. Methods: Using the unique linkage between biomedical data and prescription data from the PharmLines Initiative, we assessed the role of several risk factors used in cardiovascular risk models, using a time-dependent Cox PH model, in the occurrence of drug treatment of CVEs after initiation of statin therapy. Results: Among 602 statin therapy starters, 11% received drug treatment for CVE within an average follow-up period of 832 days. After multivariable modelling, cholesterol levels and blood pressure at baseline were no longer associated, whereas self-reported diabetes and increasing age were highly associated with the outcome when on statin therapy (hazard ratio (HR): 3.01, 95% confidence interval (95% CI): 1.48-6.12 and 1.04; 95% CI: 1.01-1.07, respectively). Males, smokers, and nonadherent patients had increased risks (HR 1.6, 1.12, and 1.18, resp.), though not statistically significant. Conclusion: Drug treatment for CVEs after statin initiation is increased in patients with diabetes type 2, in aged patients, males, smokers, and those with poor adherence, while there was no association with baseline cholesterol levels and blood pressure. These factors should be taken into account during the monitoring of statin therapy and may lead to changes in statin treatment or risk-related lifestyle factors.
