Table 4.

Diagnostic Metrics for Identifying Major Trauma Patients (Injury Severity Score ≥ 16), Based on Initial and Final Destination Hospital, Regardless of Triage Criteria, Initial Emergency Medical Services Transport to a Level I/II Trauma Center

Site	n	n Initial Level I/II	n ISS ≥ 16	Sens %	95%CI (%)	Spec %	95%CI (%)	Under-triage %	Over-triage %	PPV %	NPV %	+LR	−LR	AUC
A	15,427	9,365	1,887	93.3	(92.2–94.5)	43.9	(43.0–44.7)	6.7	56.1	18.8	97.9	1.66	0.15	0.69
B	12,071	3,890	2,101	67.8	(65.8–69.8)	75.3	(74.4–76.1)	32.2	24.7	36.6	91.7	2.74	0.43	0.72
C	8,523	6,438	926	95.9	(94.6–97.2)	27.0	(26.0–28.0)	4.1	73.0	13.8	98.2	1.31	0.15	0.61
D	3,476	1,850	100	98.0	(95.2–100)	48.1	(46.4–49.8)	2.0	51.9	5.3	99.9	1.89	0.04	0.73
E	2,300	1,321	118	91.5	(86.5–96.6)	44.4	(42.3–46.5)	8.5	55.6	8.2	99.0	1.65	0.19	0.68
F	47,644	14,979	588	55.3	(51.2–59.3)	68.9	(68.4–69.3)	44.7	31.1	2.2	99.2	1.77	0.65	0.62
G	32,904	8,996	1,380	44.1	(41.4–46.7)	73.4	(72.9–73.9)	55.9	26.6	6.8	96.8	1.66	0.76	.59
Total	122,345	46,839	7,100	73.4	(72.4–74.4)	63.9	(63.6–64.2)	26.6	36.1	11.1	97.5	2.03	0.42	0.69

EMS, emergency medical services; ISS, Injury Severity Score; sens, sensitivity; spec, specificity; CI, confidence interval; PPV, positive predictive value; NPV, negative predictive value; +LR, positive likelihood ratio; −LR, negative likelihood ratio; AUC, area under the curve.