Table 1.

Comparison of ferritin in paired serum vs. urine samples of five study groups (median and interquartile range). The P-value represents a Wilcoxon rank-sum test comparing the median of the healthy adult male group to each of the subsequent groups (except group five) in a pairwise fashion. In the case of group 5, the healthy adult male group was compared to the single value in group 5 with the Wilcoxon signed-rank test.

Study Group	N	Serum Ferritin (ng/mL)	Urine Ferritin (ng/mL)	Urine Ferritin as a percent of Serum Ferritin	P-value, urine ferritin as a percent of serum Ferritin. Various study groups vs. healthy adults
#1 Healthy adult males	5	39.4(26.6)	5.1(3.5	13%
#2 Healthy term neonates	5	48.2(72.5)	9.7(5.8)	20%	0.69
#3 Preterm neonates	8	128.0(54.5)	5.1(35)	4%	>0.90
#4 Neonates with liver disorders	5	3206(3248.6)	172.1(201.5)	5%	0.06
#5 Child with iron overload	1	382.7	9.74	3%	0.03