Table 2 .

Current and Piecewise Regression-Derived Reference Intervals (Lower Reference Limit 2.5th Percentile Value and Upper Reference Limit 97.5th Percentile Value) for Children Aged 1 to 19 Years^a

	Age, y	Current Reference Intervalsb	Age, y	Piecewise Regression-Derived Reference Intervals
RBC count, million cells/µL
Male	0.5-1	3.70-6.00	1-6	3.95-5.31
	2	4.10-5.10	7-11	4.06-5.31
	3-5	4.10-5.30	12-12	4.06-5.72
	6-11	4.20-5.10	13-15	4.32-5.72
	12-15	4.40-5.50	16-16 17-19	4.32-5.88 4.48-5.88
Female	0.5-1	3.70-6.00	1-14	3.94-5.24
	2	4.10-5.10	15-15	3.94-5.15
	3-5	4.10-5.20	16-19	3.78-5.15
	6-11	4.10-5.30
	12-15	4.10-5.20
Hemoglobin, g/dL
Male	0.5-1	10.5-13.5	1-2	10.5-14.2
	2	11.0-14.0	3-5	11.2-14.2
	3-5	11.0-14.5	6-6	11.7-14.2
	6-11	12.0-14.0	7-11	11.7-15.3
	12-15	12.8-16.0	12-12	12.1-15.3
			13-13	12.1-16.6
			14-15	12.8-16.6
			16-19	13.4-17.4
Female	0.5-1	10.5-13.5	1-3	10.7-14.1
	2	11.0-14.0	4-4	11.2-14.1
	3-5	11.8-14.7	5-6	11.2-14.6
	6-11	12.0-14.5	7-8	11.6-14.6
	12-15	12.2-14.8	9-14	11.6-15.2
			15-19	11.0-15.2
Hematocrit, %
Male	0.5-1	33.0-40.0	1-4	31.8-41.3
	2	33.0-42.0	5-5	34.3-41.3
	3-5	33.0-43.0	6-12	34.3-44.8
	6-11	35.8-42.4	13-14	36.5-48.6
	12-15	37.3-47.3	15-15	39.2-48.6
			16-19	39.2-50.8
Female	0.5-1	33.0-40.0	1-3	31.6-41.6
	2	33.0-42.0	4-4	32.7-41.6
	3-5	35.0-44.0	5-5	32.7-42.9
	6-11	35.7-43.0	6-8	34.3-42.9
	12-15	36.3-43.4	9-14	34.3-44.7
			15-19	32.9-44.7
Mean cell volume, fL
Male	0.5-5	74.0-89.0	1-2	68.0-86.9
	6-11	76.5-90.6	3-8	74.7-89.7
	12-15	81.4-91.9	9-12 13-13 14-15 16-19	74.7-90.9 74.7-93.8 77.9-93.8 77.9-95.7
Female	0.5-5	74.0-89.0	1-2	68.6-87.0
	6-11	78.5-90.4	3-4	75.3-89.2
	12-15	79.9-92.3	5 - 11 12-16 17-19	75.3-91.2 75.3-94.8 75.3-96.6
Mean cell hemoglobin, pgc
Male			1-2	22.5-29.8
			3-6	25.0-31.2
			7-13	25.0-31.6
			14-14 15-15 16-19	25.0-32.2 26.1-32.2 26.1-32.9
Female			1-2	22.3-30.3
			3-3	25.0-30.3
			4-11	25.0-31.6
			12-19	25.0-32.9
Mean cell hemoglobin concentration, g/dLc
Male			1-12	32.5-36.0
			13-19	32.5-35.7
Female			1-19	32.4-35.9
Red cell distribution width, %
Male	<2	Not established	1-2	11.4-16.3
	2	12.0-14.5	3-19	11.4-14.0
	3-5	12.0-14.0
	6-11	12.0-14.0
	12-15	11.6-13.8
Female	<2	Not established	1-2	11.2-16.3
	2	12.0-14.5	3-12	11.2-13.8
	3-5	12.0-14.0	13-19	11.2-15.3
	6-11	11.6-13.4
	12-15	11.2-13.5

^aData from National Health and Nutrition Examination Survey 1999 to 2012 (supplemental data).

^bValues from Mayo Clinic.²¹

^cCurrent reference intervals are not provided by Mayo Clinic.²¹