OBJECTIVES: Non-vitamin K antagonist oral anticoagulants (NOACs) are increasingly being used over warfarin for stroke prevention in non-valvular atrial fibrillation (NVAF) patients. However, there are limited studies on clinical outcomes of NOAC in a multi-ethnic Asian country such as Singapore. This study aims to compare the real-world effectiveness and safety between NOAC and warfarin in NVAF patients and assess the potential long-term impact on the healthcare system in Singapore.

METHODS: Using government’s linked national health record databases, patients aged 18 years and above initiated on NOAC or warfarin for NVAF from 2015 to 2018 were included in this retrospective cohort study. Patient’s demographics, comorbidities, and comedications were balanced using propensity score matching. Primary efficacy and safety endpoints were stroke or systematic embolism (SE) and intracranial haemorrhage (ICH) or gastrointestinal (GI) bleeding, respectively. Effect size was estimated using hazard ratios (HRs) with 95% confidence intervals (CIs) from Cox regression. A Markov model was used to extrapolate the number of deaths and hospitalisations avoided with NOAC initiation.

RESULTS: After propensity score matching, 3,315 comparable patients in each cohort remained. Over a median follow-up period of 2.0 years, NOAC users were less likely to develop a stroke or SE than warfarin users (HR 0.83; 95% CI 0.70-0.99). NOAC initiation was associated with a lower incidence rate of any ICH or GI bleed (HR 0.77; 95% CI 0.66-0.91) and all-cause mortality (HR 0.81; 95% CI 0.70-0.94). NOAC initiation was estimated to avoid 1,270 deaths, 622 stroke/SE hospitalisations and 1,311 ICH/GI bleed hospitalisations, which could contribute to $28 million saved over 10 years. CONCLUSION: Consistent with clinical trials and other real-world findings, this large cohort study confirmed that NOAC reduced risk of stroke or SE, ICH/GI bleed and avoid all-cause mortality, and has potential to bring about cost savings to the healthcare system.