Efficacy and Safety of Different Doses of Rivaroxaban in Elderly Chinese Patients With Nonvalvular Atrial Fibrillation

Inclusion Criteria: * Age≥75 years * Chinese patient: male or female * Patients had to be diagnosed as nonvalvular atrial fibrillation (NVAF) Exclusion Criteria: * Patients with anemia (hemoglobin\<100g/L), known human immunodeficiency virus infection, female patients who were pregnant or lactating and patients for whom warfarin was contraindicated, were also excluded * Patients with calculated creatine clearance vulue\<30ml/min * Patients expected to chronically use a non-steroidal anti-inflammatory agent (except for external preparations) and those treated with a strong cytochrome P4503A4 inhibitor (eg, ketoconazole, clarithromycin, or protease inhibitors) or a strong cytochrome P450 3A4 inducer (eg, rifampicin) during the trial