Table 2. Comparison of serum parameters obtained by 3 mL and 5 mL discarded volume methods.

Parameters	Discarded blood volume mean (SD) or median (IQR)		p value a
	3 mL ( N = 64)	5 mL ( N = 64)
Abbreviations: IQR, interquartile range; SD, standard deviation. a Paired t -test or Wilcoxon signed rank test.
Sodium (mEq/L)	135.7 (8.2)	136.1 (8.1)	0.369
Potassium (mEq/L)	3.9 (3.5, 5)	3.9 (3.5, 5.1)	0.295
Calcium (mg/dL)	7.9(7.5, 8.6)	7.9 (7.5, 8.6)	0.119
Creatinine (mg/dL)	1.1 (0.7, 3.5)	1.1 (0.6, 3.4)	0.470
Total bilirubin (mg/dL)	0.7 (0.4, 1.1)	0.7 (0.5, 1.1)	0.197
Direct bilirubin (mg/dL)	0.2 (0.1, 0.6)	0.2 (0.1, 0.6)	0.284