Primary Non-Adherence and Associated Factors in Patients with Atrial Fibrillation in Germany: A Retrospective Cohort Study

Abstract

Background: Primary non-adherence (PNA)—failure to dispense a newly prescribed medication—is an early barrier to effective treatment. This study aimed to estimate PNA to oral anticoagulants in patients with atrial fibrillation (AF) in Germany and to identify associated factors. Methods: In this retrospective cohort study, first prescriptions of vitamin K antagonists (VKAs), direct thrombin inhibitors, or direct factor Xa inhibitors issued to AF patients between 2016 and 2025 in the IQVIA Disease Analyzer database were combined with pharmacy dispensing records in the Longitudinal Prescription (LRx) database. First prescriptions preceded by a dispensing of the same class within 365 days were excluded. PNA was defined as failure to dispense within 30 days; associated factors were assessed using logistic regression with generalized estimating equations. Results: The study included 57,290 first prescriptions in 53,815 patients (mean age 75.5 years; 49.7% women). PNA occurred in 10.6% (VKAs 14.4%, direct thrombin inhibitors 11.7%, direct factor Xa inhibitors 10.1%). Direct factor Xa inhibitors (odds ratio [OR] 0.67; 95% confidence interval [CI] 0.62–0.72), prior myocardial infarction (OR 0.79), and dementia (OR 0.85) were associated with lower odds of PNA, whereas ischemic heart disease (OR 1.18) and hypertension (OR 1.11) were associated with higher odds. Non-dispensing of the first prescription was strongly associated with non-dispensing of subsequent prescriptions. Conclusions: Approximately one in ten first oral anticoagulant prescriptions in AF was not dispensed within 30 days, most frequently for VKAs.