Table 2. Sensitivity, specificity and negative predictive value of R-time to detect DOAC concentrations above thresholds mentioned.

DOAC	Threshold	R-time	Sensitivity	Specificity	LR+	LR−	NPV
	≥(ng/mL)	≥(min)	%	%			%
Dabigatran
	30	2.6	100	92 (82–100)	13	0	100
	50	3.1	94 (88–100)	83 (70–95)	5.5	0.07	91 (81–100)
	100	3.4	100	82 (72–93)	5.6	0	100
Rivaroxaban
	30	1.7	98 (94–100)	86 (73–99)	6.9	0.02	96 (88–100)
	50	2.1	95 (89–100)	80 (67–93)	4.8	0.06	93 (84–100)
	100	2.6	96 (78.9–99.9)	85 (72.4–93.3)	5.1	0.05	98 (93–100)
Apixaban
	30	c
	50	1.7	100	96 (88–100)	25	0	100
	100	2.2	98 (93–100)	81 (67–95)	5	0.03	96 (89–100)

Abbreviations: AFXa, antifactor-Xa; AUC, area under the curve; DOAC, direct oral anticoagulant; DTI, direct thrombin inhibitor; LR + , positive likelihood ratio; LR − , negative likelihood ratio; NPV, negative predictive value; R, reaction time.

Note: The reference range of R-time for the FXa channel is 0.6–1.5 minutes, and for DTI channel is 1.6–2.5 minutes.

^aIndicates using the DTI channel.

^bIndicates using the AFXa channel.

^cDue to only single acquired concentration between 30 and 49 ng/mL, no calculations were performed.