In non-valvular atrial fibrillation (AF), oral anticoagulation reduces the risk of thromboembolism such as stroke and systemic embolism (SSE), but increases the risk of major bleeding such as intracranial haemorrhage (ICH). The risk-benefit balance between SSE versus ICH can be expressed as the net clinical benefit (NCB); however, the risk of SSE and ICH varies according to clinical factors that can be assessed using CHADS2, CHA2DS2-VASc (both quantifying risk of stroke) and HAS-BLED (quantifying risk of major bleeding) scores, respectively.