Figure 15 shows one of the results of the study referenced in the previous Figure.[11]  It can be seen that not one of these groups of patients with AFib, arrayed across the x-axis according to deciles of age, consistently spent >60% of time in the warfarin therapeutic INR range, indicated by the red line.  Thus is yet another study that serves as something of a wake-up call, because these results remind us that if we are using warfarin, then one of the challenges must be to try to improve the time in the therapeutic range (TTR). 

These results suggest that it may be the case that individuals who, despite being adherent to their warfarin regimens, are nonetheless unable to hit this TTR target, should perhaps be targeted more aggressively by their physicians or be switched  off of warfarin to a NOAC.