Can bleeding risk when switching from VKA treatment to a NOAC in frail, elderly patients be accurately compared if individual times in therapeutic range while on VKA treatment are not captured?  

It has been postulated that, among patients who do not have an INR within therapeutic range, about half have subtherapeutic values and half have supratherapeutic values. Therefore, the latter are at higher risk of bleeding complications. Time in therapeutic range (TTR) ranges around 60-70% in random...

While this study addresses a very clinically relevant subject, I believe that the lack of documentation of time in the therapeutic range (TTR) is a very substantial limitation. Similarly, one would need to carefully consider the TTR of an individual patient when considering transitioning them from V...