Table 2. Diagnostic performance of the point-of-care and laboratory high-sensitivity cardiac troponin I assays performed using the initial blood samples.

Population	Assay	Positive	Negative	MI	Non-MI	Sensitivity(95% CI)	Specificity(95% CI)	P value	PPV(95% CI)	NPV(95% CI)
Overall(N=585)	POC	56	529	14	571	100% (76.8 to 100.0)	92.6% (90.2 to 94.7)	< 0.001	25.0% (20.0 to 30.8)	100% (99.3 to 100.0)
	Laboratory	82	503	14	571	100% (76.8 to 100.0)	88.1% (85.2 to 90.6)		17.1% (14.1 to 20.5)	100% (99.3 to 100.0)
Male(N=304)	POC	35	269	9	295	100% (66.4 to 100.0)	91.2% (87.4 to 94.2)	= 0.001	25.7% (19.3 to 33.3)	100% (98.6 to 100.0)
	Laboratory	50	254	9	295	100% (66.4 to 100.0)	86.1% (81.6 to 89.8)		18.0% (14.2 to 22.6)	100% (98.6 to 100.0)
Female(N=281)	POC	19	262	5	276	100% (47.8 to 100.0)	94.9% (91.6 to 97.2)	< 0.001	26.3% (17.7 to 37.3)	100% (98.6 to 100.0)
	Laboratory	43	238	5	276	100% (47.8 to 100.0)	86.2% (81.6 to 90.1)		11.6% (8.9 to 15.0)	100% (98.5 to 100.0)
Younger(<65 years)(N=248)	POC	13	235	4	244	100% (39.8 to 100.0)	96.3% (93.1 to 98.3)	= 0.289	30.8% (20.0 to 45.8)	100% (98.4 to 100.0)
	Laboratory	17	231	4	244	100% (39.8 to 100.0)	94.7% (91.1 to 97.1)		23.5% (15.4 to 34.3)	100% (98.4 to 100.0)
Older(≥65 years)(N=337)	POC	41	296	10	327	100% (69.2 to 100.0)	90.5% (86.8 to 93.5)	< 0.001	24.4% (18.8 to 31.1)	100% (98.8 to 100.0)
	Laboratory	76	261	10	327	100% (69.2 to 100.0)	79.8% (75.1 to 84.0)		13.2% (10.9 to 15.8)	100% (98.6 to 100.0)

The McNemar test was used to produce the P values given.

MI, myocardial infarction; N, number; NPV, negative predictive value; POC, point-of-care; PPV, positive predictive value