Table 2.

Cardiac testing, radiation exposure, disposition, length of hospital stay, time to diagnosis, and healthcare costs as predicted using decision rules based on hs-cTnI and cardiovascular risk factors vs as observed in the ROMICAT II trial.

	ROMICAT II as observed (n = 255)	ROMICAT II as predicted (n = 255)	P
Cardiac testing (%)a			<0.001
No testing	0 (0.0)	86 (33.7)
1 test	203 (79.6)	127 (49.8)
≥2 tests	52 (20.4)	42 (16.5)
Invasive coronary angiography (%)	23 (9.0)	22 (8.6)	1.000
Intervention (%)
PCIb	14 (5.5)	14 (5.5)	1.000
CABG	1 (0.4)	1 (0.4)	1.000
Cumulative radiation exposure, mSv/patientc	10.2 ± 11.9	7.7 ± 12.4	<0.001
Disposition			<0.001
ED discharge	62 (24.3%, 95% CI, 19.1–30.1%)	128 (50.2%, 95% CI, 43.9–56.5%)
Observational unit admission	150 (58.8%, 95% CI, 52.5–64.9%)	92 (36.1, 95% CI, 30.2–42.3%)
Hospital admission	41 (16.1%, 95% CI, 11.8–21.2%)	34 (13.3%, 95% CI, 9.4–18.1%)
Left against medical advice	2 (0.8%, 95% CI, 0.1–2.8%)	1 (0.4%, 95% CI, 0.0–2.1%)
Length of hospital stay, hours			<0.001
Median (25th-75th percentile)	21.4 (8.0–28.6)	8.2 (2.0–27.1)
Time to diagnosis, hours			<0.001
Median (25th-75th percentile)	8.2 (5.8–22.7)	5.7 (1.0–20.4)
Healthcare cost per patient in US$
Median (25th-75th percentile)	2698 (2698–2698)d	2698 (655–2698)d	<0.001
Mean ± SD	4066 ± 4858	3342 ± 5089
Non-ACS patients only
Median (25th-75th percentile)	2698 (1836–2698)	1837 (655–2698)	<0.001
Mean ± SD	2922 ±1425	2136 ±1634

^aCardiac testing included coronary computed tomography angiography, exercise treadmill test, stress echocardiography, nuclear myocardial perfusion imaging, and invasive coronary angiography.

^bCABG, coronary artery bypass grafting; PCI, percutaneous coronary intervention.

^cRadiation exposure included exposure from coronary computed tomography, nuclear myocardial perfusion imaging, and invasive coronary angiography.

^dBecause all changes in costs occurred in patients below the median of costs, observed and predicted median costs values are identical.