Table 4.

Reference Intervals of K, Na, and Cl in Adult Healthy Chinese Han population

				Percentile
Ion	Group	No.	Method	2.5th	50th	97.5th	RIs by manufacture
K (mmol/l)	Male	1,916	Indirect	3.6 (3.61–3.69)	4.3	5.3 (5.22–5.32)	3.5–5.5
	Female	2,608	ISE	3.6 (3.60–3.65)	4.2	5.1 (5.10–5.19)
	Combined	4,524		3.6 (3.61–3.65)	4.3	5.2 (5.18–5.24)
Na (mmol/l)	Male	1,916	Indirect	136 (136.0–136.6)	142	147 (146.2–147.0)	130–150
	Female	2,608	ISE	136 (135.1–136.0)	141	146 (146.0–146.4)
	combined	4,524		136 (135.9–136.1)	141	146 (146.1–146.5)
CL (mmol/l)	Male	1,916	Indirect	99 (98.2–98.7)	104	109 (108.7–109.3)	94–110
	Female	2,608	ISE	99 (98.7–99.2)	104	110 (109.6–110.3)
	combined	4,524		99 (98.5–98.9)	104	110 (109.3–109.8)

Ninety percent confidence interval values of 2.5th and 97.5th percentiles were shown in the parentheses.