Adherence to QD vs. BID Medications in NVAF Patients is Associated With Reduced Risk of Ischemic Stroke: A Modeling Study Using RCT and Claims Datad

Background: Non vitamin-K antagonist oral anticoagulants (NOACs) reduce stroke risk compared with no treatment among non-valvular atrial fibrillation patients (NVAF). However, poor medication adherence can undermine therapeutic efficacy, which may be more affected by twice (BID) vs. once (QD) daily medication. Objective: To estimate the impact of lower adherence rates of BID vs QD therapies on stroke risk in NVAF patients. Methods: As a first step, claims from the Truven Health Analytics MarketScan databases (7/2012-10/2015) were analyzed to evaluate the relationship between adherence (proportion of days covered [PDC] ≥ 0.8) to NOACs and the risk of stroke at 1 year. As a second step, the relationship between stroke and adherence established in Step 1 was calibrated using the risk of stroke from previous randomized controlled trials (RCTs) for placebo vs NOACs. In a third step, findings from a published meta-analysis (Coleman et al.; CMRO 2012) that characterized adherence to BID (PDC=0.738) and QD (PDC=0...