Time Trends in Intracranial Bleeding and New Oral Anticoagulant Prescription

Abstract

Objectives & BackgroundDabigatran, rivaroxaban and apixaban were approved for stroke prevention in the past 4 years. Phase 3 studies reported a lower risk of intracranial bleeding compared to warfarin however there is little real-life data to validate this. We assessed time trends in oral anticoagulant (OAC) associated intracranial bleeding between 2009 and 2013. We compared bleeding rates to provincial OAC prescription trends.MethodsICD-10 codes were used to identify all atraumatic intracranial bleeds presenting to our neurosurgical centre (covering a population of 1.3 million). Trained researchers extracted data on anticoagulant medication in the week prior to diagnosis of intracranial bleed. Provincial prescription data for OACs were obtained from IMS Brogan CompuScript Market Dynamics. The primary outcome was the incident OAC-associated intracranial bleed time trend between 2009 and 2013. The secondary outcomes were the non-OAC associated intracranial bleed time trend, and the provincial OAC prescription trends.Results2050 patients presented with atraumatic intracranial bleeds. 371 (18%) patients were prescribed an anticoagulant, of which 335 were OACs. There was an increasing trend over time in the rate of anticoagulant associated bleeding (p=0.009) and non-anticoagulant associated bleeding (p=0.063). Warfarin accounted for a disproportionately large number of all OAC-associated bleeds compared to prescription prevalence. Dabigatran, rivaroxaban and apixaban accounted for a smaller proportion of OAC bleeds when compared to prescription prevalence.ConclusionWe found an increasing number of patients treated for intracranial bleeding over time. Warfarin accounted for a disproportionate number of intracranial bleeds and the new oral anticoagulants, fewer than expected.