Table 4. Sensitivity and Specificity Estimates for Identifying Patients With Serious Injury or Resource Use With Different Hospital LOS Cut-points, by Age Group.

	LOS (days)	Sensitivity (%)	Specificity (%)
A. Children (0–14 yr)
California ED patients	≥1	34.8	98.8
	≥2	29.7	99.5
	≥3	24.6	99.8
	≥4	20.1	99.9
	≥5	15.9	99.9
California injury admissions	≥1	98.4	9.4
	≥2	84.2	60.9
	≥3	69.7	82.3
	≥4	57.0	90.4
	≥5	45.1	93.9
Oregon Trauma Registry	≥1	97.1	8.9
	≥2	85.4	63.5
	≥3	73.2	80.2
	≥4	61.5	87.6
	≥5	49.6	91.9
B. Children (15–64 yr)
California ED patients	≥1	73.5	97.1
	≥2	66.0	98.0
	≥3	57.4	98.7
	≥4	48.9	99.1
	≥5	41.0	99.4
California injury admissions	≥1	97.9	7.8
	≥2	87.8	36.2
	≥3	76.4	57.1
	≥4	65.1	71.9
	≥5	54.6	81.1
Oregon Trauma Registry	≥1	98.2	11.1
	≥2	92.6	50.3
	≥3	84.4	67.4
	≥4	76.1	77.7
	≥5	67.0	84.3
C. Elders (≥ 65 yr)
California ED patients	≥1	91.6	86.2
	≥2	89.3	87.5
	≥3	85.3	89.2
	≥4	74.4	92.4
	≥5	59.4	95.0
California injury admissions	≥1	99.7	1.5
	≥2	97.2	10.9
	≥3	92.8	23.0
	≥4	80.9	45.5
	≥5	64.7	64.1
Oregon Trauma Registry	≥1	98.8	3.0
	≥2	93.1	28.5
	≥3	85.9	42.2
	≥4	77.7	56.8
	≥5	69.5	67.4
Oregon and Washington Medicare patients	≥1	99.8	0.7
	≥2	97.1	10.6
	≥3	92.5	22.1
	≥4	80.4	45.0
	≥5	62.7	63.5

LOS = length of stay.