How do you measure the oral anti-Xa anticoagulants rivaroxaban, apixaban, edoxaban, and betrixaban?

Primary tabs

Prothrombin time (PT)
2% (1 vote)
Activated partial thromboplastin time (APTT, PTT)
2% (1 vote)
Chromogenic anti-Xa assay with specific calibrators
54% (32 votes)
We don't measure the anti-Xa anticoagulants
42% (25 votes)
Total votes: 59