Table 4.

Validation of electrolyte reference intervals in five laboratories in Changchun.

Analytes	Age group	Sex group	Reference intervals	N a	Lab 1		Lab 2		Lab 3		Lab 4		Lab 5
					n b	Resultc	n b	Resultc	n b	Resultc	n b	Resultc	n b	Resultc
Potassium (mmol/L)	2 to < 4 years	F + M	3.96–5.39	20	0	100	0	100	1	95	1	95	2	90
	4 to < 12 years	F + M	3.73–5.27	20	0	100	0	100	2	90	1	95	1	95
	12 to < 15 years	F + M	4.14–5.39	20	0	100	1	95	0	100	1	95	0	100
Sodium (mmol/L)	2 to < 9 years	F + M	136.4–146.8	20	0	100	2	90	1	95	2	90	1	95
	9 to < 11 years	F + M	121.8–146.4	20	0	100	1	95	2	90	1	95	2	90
	11 to < 13 years	F + M	136.9–148.6	20	0	100	0	100	1	95	1	95	0	100
	13 to < 15 years	F	134.5–146.4	20	2	90	1	95	2	90	1	95	0	100
		M	138.6–149.2	20	1	95	1	95	1	95	0	100	1	95
Chlorine (U/L)	2 to < 11 years	F + M	94.6–106.4	20	0	100	0	100	1	95	0	100	0	100
	11 to < 13 years	F + M	98.4–108.8	20	0	100	1	95	0	100	1	95	1	95
	13 to < 15 years	F	93.9–107.4	20	1	95	1	95	0	100	0	100	1	95
		M	97.1–107.5	20	0	100	0	100	1	95	1	95	1	95
Calcium (mmol/L)	2 years	F + M	2.00–2.64	20	0	100	1	95	0	100	1	95	0	100
	3 to < 13 years	F + M	1.95–2.57	20	0	100	1	95	1	95	0	100	1	95
	13 to < 15 years	F	1.96–2.32	20	2	90	1	95	1	95	1	95	0	100
		M	1.96–2.37	20	1	95	0	100	1	95	0	100	1	95
Phosphorus (mmol/L)	2 years	F + M	1.39–2.65	20	0	100	0	100	1	95	1	95	0	100
	3 to < 8 years	F + M	1.32–2.03	20	0	100	1	95	1	95	1	95	0	100
	8 to < 11 years	F + M	1.26–1.89	20	0	100	1	95	0	100	0	100	1	95
	11 to < 13 years	F + M	1.29–1.91	20	0	100	1	95	1	95	1	95	0	100
	13 to < 15 years	F	1.10–1.61	20	1	95	0	100	1	95	0	100	2	90
		M	1.00–1.99	20	0	100	1	95	0	100	1	95	1	95

M, male; F, female. ^aNumber of validation samples of this study. ^bNumber of validation samples outside the reference intervals of this study. ^cThe results of percentage of validation samples inside the reference intervals of this study.