Non-persistence risk and health care resource utilization of Italian patients with non-valvular atrial fibrillation

The aim of this study is to compare discontinuation risk and health care resource utilization between vitamin K antagonists (VKAs) and non-vitamin K antagonist oral anticoagulants (NOACs) in newly treated patients with non-valvular atrial fibrillation (NVAF). Based on administrative databases of five Italian Local Healthcare Units, all patients with a discharge diagnosis of NVAF between 2011 and 2014 were selected. Among them, the incident users of NOACs and VKAs in 2014 were followed-up to from the first prescription date to the occurrence of anyone of the following events: a 90-day gap in therapy, switch to a different molecule or add-on of a different molecule into the regimen, death of patient, end of follow-up (December 2015). All-cause hospitalizations, outpatient visits and examinations within the persistence period were also evaluated. The final cohort was composed of 2909 and 765 incident users of VKA and NOACs, respectively. Cox regression to model time to non-persistence within 12 months showed a 62% reduction in risk of drug discontinuation in NOAC patients compared to VKA patients (HR,0.38 [0.33-0.44]). In the adjusted analyses with warfarin as reference, apixaban patients (HR, 0.35 [0.24-0.50]) had the lowest risk of non-persistence, followed by rivaroxoban (HR, 0.42 [0.33-0.54]) and dabigatran users (HR, 0.51 [0.43-0.61]). The mean total numbers of all-cause hospitalization records in 12-month persistent patients were significantly less in NOACs users compared with VKA users (0.36 vs 0.47, p-value:0.03). Similarly, the differences in the mean numbers of all-cause visits and examinations were statistically significant between VKA and NOAC patients, who registered on average 2.33 vs 1.84 visits (p-value: 0.01) and 24.4 vs 9.2 exams referrals (p-value: <0.0001), respectively. NOACs showed a better profile in terms of both resource utilization and persistence compared with VKAs. In particular, apixaban returned the lowest risk of discontinuation than dabigatran and rivaroxaban.