Non-vitamin K antagonist oral anticoagulants have better efficacy and equivalent safety compared to warfarin in elderly patients with atrial fibrillation: A systematic review and meta-analysis

The protocol of this meta-analysis was registered on PROSPERO under CRD42016047922 (https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42016047922).