Assessment of direct oral anticoagulant assay use in clinical practice

There are no clear and consistent guidelines on how to utilize DOAC assays, and reports on the use of DOAC levels in clinical practice is limited. The objective of this study was to analyze why DOAC levels are ordered, how the results affect clinical decision-making, and to determine if DOAC assays are utilized appropriately. This was a retrospective chart review study analyzing 150 dabigatran, rivaroxaban, and apixaban levels performed at a single institution. The majority of DOAC assays were ordered in situations or special patient populations where confirming absence or detecting presence of drug may be useful. The most common indication for ordering assays was prior to an invasive procedure. Most DOAC levels were timed appropriately but peak levels were most likely to be incorrectly ordered. Clinical decisions following level results depended on indication for ordering and were most commonly used to determine whether or not to proceed with an invasive procedure. The results of our study suggest while DOAC assays are generally ordered for useful indications, there is still a lack of understanding of when levels should be drawn and how to interpret DOAC assay results.