Low Persistence of Antithrombotic Agents is Associated with Poor Outcomes after First-ever Acute Ischemic Stroke.

Objective: This study investigated the time-trend persistence with antithrombotic agents (AT) and assessed the impact of AT persistence on outcome events and adverse events (AE) within two years after first-ever acute ischemic stroke (IS).

Methods: Using Taiwan's National Health Insurance claims dataset, 7,341 IS subjects hospitalized between 2001 and 2005 with AT prescribed at discharge and survived at least 3 months were followed up for 2 years. Time-trends of AT usage were analyzed. Medication persistence was assessed as the proportion of days covered (PDC) for filled prescription, and categorized into low, intermediate and high persistence. Multivariate logistic regression analysis and multivariate Cox proportional hazard regression models were performed to identify factors associated with AT persistence and its impact on vascular outcomes.

Results: AT persistence rates declined sharply from 81% to 52% during the first 6 months. In addition to patient and facility-level characteristics, occurrence of AE (e.g., GI bleeding/ulceration, fractures/ major trauma, and iatrogenic/unspecific illness) was inversely related to AT persistence. Compared with patients with low persistence, the composite risk of recurrent stroke, cardiovascular disease, or death from any cause was significantly lower in patients with intermediate (Hazard Ratio [HR] 0.64, 0.57-0.71) or high AT persistence (0.74, 0.66-0.83).