Pulmonary vascular disease & thromboembolismCohort study
Bleeding Risk With Apixaban Versus Rivaroxaban: A Reference Trial Emulation Predicting the Results of COBRRA-VTE and COBRRA-AF Using US Health Care Claims
- cohort studies designed to emulate COBRRA-VTE and COBRRA-AF
- 3 US health care insurance claims databases (Medicare, Optum Clinformatics, Merative MarketScan)
- 1:1 propensity score matching
- fixed-effects meta-analyses
- Protocols were preregistered on ClinicalTrials.gov before inferential analyses were conducted
Authors' conclusion
In database studies that closely emulated the design and measurements of the COBRRA-VTE and COBRRA-AF trials, a substantially lower risk of bleeding with apixaban was observed, consistent with the results of COBRRA-VTE (published after completion of our analyses), and indirect comparisons from other trials.
Study context
- Population
- Patients with venous thromboembolism (VTE) and atrial fibrillation (AF) in US health care insurance claims databasesmatched pairs per emulation · COBRRA-VTE emulation 14,023 matched pairs · COBRRA-AF emulation 176,990 matched pairs
- Exposure
- the risk of bleeding with apixaban was evaluated relative to the risk with rivaroxaban
- Outcome
- Composite of:
- Major bleeding
- Clinically relevant non-major bleeding recorded in the inpatient setting
Main finding
As reported in the abstract
apixaban
12.8
COBRRA-VTE emulation · COBRRA-AF emulation 6.4
rivaroxaban
19.1
COBRRA-VTE emulation · COBRRA-AF emulation 9.2
apixaban vs rivaroxabanHazard ratio (95% CI)
COBRRA-VTE emulation; 31% decreased risk
0.69(0.59–0.79)
COBRRA-AF emulation; 31% decreased risk
0.69(0.66–0.71)
Observational data: associations, not effects.
Original publication
Bleeding Risk With Apixaban Versus Rivaroxaban: A Reference Trial Emulation Predicting the Results of COBRRA-VTE and COBRRA-AF Using US Health Care Claims. Circ Popul Health Outcomes. Published 2 July 2026. doi:10.1161/circoutcomes.125.012892
Summarised from the published abstract; every number is checked against it