OBJECTIVES: The objective of this study is to evaluate patterns of prescription switching in atrial fibrillation (AF) patients initiated on a direct oral anticoagulant (DOAC) and previously naïve to anticoagulation (AC) therapy. METHODS: Data was obtained from Truven Health MarketScan® Commercial and Medicare Supplemental Databases from January 1, 2009 to December 31, 2013. AC naïve (those without prior anticoagulant use) AF patients initiated on a DOAC, with 6 months of continuous health plan enrollment before and after index date and maintained on continuous therapy for a minimum of 6 months were included. RESULTS: A total of 34,022 AC naïve AF patients initiating a DOAC were included. Of these, 6,613 (19.4%) patients switched from an index DOAC prescription to an alternate anticoagulant and 27,409 (80.6%) remained on the DOAC (age: 68.5±11.7 vs. 67.1±12.7 years, p<0.001; males: 3,781 (57.2%) vs. 17,160 (62.6%), p<0.001, respectively). A majority of patients received dabigatran as their index DOAC (N=23,521; 69.1%), followed by rivaroxaban (N=9,875; 29.0%) and apixaban (N=626; 1.8%). Amongst those that switched their medication, 3,196 (48.3%) did so within the first 6 months of therapy and 4,574 (69.2%) within the first 12 months. Overall, 2,945 (44.5%) patients switched to warfarin, 2,912 (44.1%) switched to another DOAC and 756 (11.4%) switched to an injectable anticoagulant. The highest proportion of patients switched from dabigatran to warfarin (N=2,320; 35.1%) or rivaroxaban (N=2,252; 34.1%). The median time to switch to another DOAC was 309.5 days vs. 128.0 days (p<0.001) to switch to warfarin. CONCLUSIONS: In AF patients newly initiated on DOAC therapy, one in five patients switch to an alternate anticoagulant and one of every two patients do so within the first six months of therapy. Switching from an initial DOAC prescription to traditional anticoagulants occurs as frequently as switching to an alternate DOAC. Further investigation is warranted to assess the potential causes of switching.