As can be seen in the table, initiation of warfarin therapy has been stable for over a year since the introduction of the first of these NOACs.[119] The share of dabigatran increased in use pretty quickly and then declined when rivaroxaban was approved.  These 2 agents now represent about half the market, but given the preceding review of all the clinical trial results, and given the well-known disadvantages and challenges with warfarin, the question has to be: 

Why is warfarin still being used in the other half of the market?  

What physicians must ponder is what could be the reason to choose warfarin over the NOACs when warfarin is less convenient, no more effective, has a greater risk for bleed in the head, and burdens both physicians and patients with far more side effects and interactions.