To investigate the rates and contributing factors to adverse drug events for patients treated with non-vitamin K antagonist oral anticoagulants versus warfarin, a vitamin K antagonist

An adverse drug event (ADE) for this thesis is defined as harm from a medication resulting in hospitalisation. Oral anticoagulants are among the most common drugs worldwide which contribute to medication-related ADEs. These oral anticoagulants include the non-vitamin K antagonist oral anticoagulant (NOACs) and warfarin, a vitamin K antagonist. According to the evidence, there are conflicting studies which have cited significant and non-significant differences between NOACs and warfarin, with regard to ADEs, including haemorrhage, ischaemic stroke and venous thromboembolism (VTE). The majority of these studies have been clinical trials and do not include post-marketing surveillance. This thesis compares population-adjusted rates and risk of ADEs for NOACs (apixaban and rivaroxaban) and warfarin for a cohort of patients residing in the Illawarra Shoalhaven region of NSW. In addition, this study investigated potential contributing factors for oral anticoagulant-related ADEs resulting in hospitalisation.