Adherence and persistence to rivaroxaban in non-valvular atrial fibrillation patients receiving 30- or 90-day supply prescription fills.

BACKGROUND: It is unclear whether 90-day supply fills of rivaroxaban result in better adherence and persistence compared to 30-day supply fills. We assessed patients' adherence and persistence to rivaroxaban at 12- and 24-months in nonvalvular atrial fibrillation (NVAF) patients whose rivaroxaban prescriptions were filled every 30- versus 90-days. METHODS: Using the IBM MarketScan Commercial and Medicare Supplemental data sets, we identified adult NVAF patients with ≥12-months of continuous insurance coverage who filled a prescription in May 2018 and their immediate subsequent prescription for rivaroxaban for the same days' supply. We propensity score matched 30- and 90-day rivaroxaban interval fill patients and compared the percentage with a proportion of days covered (PDC) ≥80%, mean PDC and percentage persistent to rivaroxaban therapy over 12- and 24-months of follow-up. RESULTS: Following propensity score matching, 2237 patients were included in the rivaroxaban 30- and 90-day supply fill cohorts. The proportion of patients with a PDC ≥80% was greater in the 90-day versus 30-day cohort at both 12-months (odds ratio [OR] = 1.75, 95% confidence interval [CI] = 1.54-1.97) and 24-months (OR =1.78, 95%CI =1.58-2.00), as were mean PDC values (absolute difference in mean PDC =9.4%, 95%CI =8.2-10.7% at 12-months and 11.2%, 95%CI =9.5-12.9% higher at 24-months, respectively). Persistence to rivaroxaban was not found to significantly differ between the 30- and 90-day supply cohorts at 12- or 24-months (assuming a 30-day permissible gap); however, greater persistence was observed with 90-day fills at both time points when a 14-day gap was utilized (HR =1.22, 95%CI =1.10-1.36 at 12-months and HR =1.12, 95%CI =1.02-1.22 at 24-months). CONCLUSIONS: Dispensing 90-day supply fills of rivaroxaban appears to increase the proportion of patients achieving acceptable (PDC ≥80%) adherence as well as mean adherence compared to 30-day supply fills. Ninety-day rivaroxaban fills may also result in improved persistence versus 30-day fills.