(P-252) Safety and Effectiveness of Rivaroxaban in First-time Users with Non-valvular Atrial Fibrillation in Routine Practice

Background: A post-authorisation study programme of rivaroxaban use was conducted between 2011–2020.

Objectives: To study safety and effectiveness among first-time users of rivaroxaban (RVX) or standard of care (SOC: vitamin K antagonist) for stroke prevention in atrial fibrillation (AF) in routine practice.

Methods: This cohort study used data from four European countries: IQVIA Medical Research Data-UK (IMRD-UK) in the UK, the German Pharmacoepidemiological Research Database (GePaRD), the Dutch PHARMO Database Network and Swedish national health registries. Patients ≥2 years with a first prescription of RVX or SOC from December 2011–December 2017 and a diagnostic code for AF (non-valvular) were followed until the date of each outcome of interest (intracranial [ICB], gastrointestinal [GIB], urogenital [UGB] or other [OB] bleeding leading to hospitalization), ischaemic stroke [IS], myocardial infarction [MI], death or study end (December 2017 or December 2018, country-dependent).
Unadjusted incidence rates (IR; [95% CI]) per 100 person-years of bleeding events in the first treatment period were calculated for RVX and SOC users and IS, MI and mortality in RVX users only. In the nested case-control analysis, adjusted relative risk was estimated using odds ratio (OR; [95% CI]) for each safety outcome per database.

Results: Overall, 162 919 (RVX) and 177 758 (SOC) first-time users were identified. IR of ICB in RVX users ranged from 0.25 (0.18–0.34) to 0.63 (0.61–0.85), and from 0.30 (0.24–0.38) to 0.80 (0.75–0.85) in SOC users. IR of GIB ranged from 0.49 (0.39–0.61) to 1.72 (1.66–1.78) in RVX users and 0.30 (0.24–0.37) to 1.42 (1.19–1.66) in SOC users. IR of IS ranged from 0.31 (0.24–0.41) to 1.52 (1.35–1.71) for RVX users.

RR of ICB for RVX use vs non-use ranged from 0.82 (0.64–1.06) to 1.71 (0.98–2.96) (statistically significant in one database); RR for SOC use vs non-use ranged from 1.30 (1.14–1.49) to 5.91 (3.23–10.81) (statistically significant in 3 databases). RRs for GIB comparing use vs non-use of RVX or SOC ranged from 1.04 (0.85–1.28) to 2.11 (1.31–3.38) (statistically significant in 3 databases) and 1.00 (0.89–1.13) to 4.08 (2.85–5.83) (statistically significant in 2 databases), respectively.

Other bleeding and effectiveness outcomes will be presented.

Conclusions: Observed incidence rate estimates broadly agreed with those from previous observational studies and RCTs. Compared with RVX, current use of SOC was more often associated with statistically significant increased RR of ICB. For GIB, a statistically increased RR was more often observed for RVX than for SOC. Observed variations may reflect data source and healthcare system differences.