BackgroundDetailed data on real-life utilization of vitamin K antagonists (VKAs) and new oral anticoagulants (NOACs) in atrial fibrillation are sparse. ObjectivesTo describe the dynamics of VKA and NOAC use: that is, (i) how patients moved in and out of, as well as between, use of VKAs and NOACs; (ii) how patients adhered to treatment; and (iii) which type of prescriber initiated, maintained, and changed treatment with VKAs and NOACs. MethodsWe conducted a drug utilization study in the region of southern Denmark (population 1.2 million) using prescription data. We included all subjects using VKAs or NOACs during the period of August 22, 2011, through June 30, 2013, restricted to subjects with a diagnosis of atrial fibrillation. ResultsWe identified 20911 subjects, of whom 20769 and 1639 used VKAs and NOACs, respectively. The number of VKA users was stable at similar to 14000 subjects during the study period, whereas the number of NOAC users increased to 903. The majority of NOAC users had previously used VKAs (n=974), whereas 389 anticoagulant-naive users initiated NOAC therapy. Among the latter, 51.2% had changed to VKAs within 6months. 57.3% of VKA users were initiated by a hospital physician, whereas maintenance treatment was predominantly handled by the patient's general practitioner (97.6%). Switches from NOAC to VKA were initiated by a general practitioner in 69.2% of the cases. For users of NOACs, these numbers were 73.5%, 94.0%, and 63.3%. ConclusionsA large proportion of NOAC users switch to a VKA within a short time frame. The reasons for this are not clear.
Journal of Thrombosis and Haemostasis, 2014, Vol 12, Issue 9, p. 1413-1418
anticoagulants atrial fibrilliation coumarins dabigatran drug utilization WARFARIN