Metals and kidney markers in adult offspring of endemic nephropathy patients and controls: a two-year follow-up study

Table 2 Metals and metalloids in urine and serum in two consecutive investigations

	Variable	N	Median	5%-value	95%-value	Spearman correlation coefficient (p)	ICC	ICC 5%-value
As in urine (μg/L)	2003/04	201	3.10	0.70	9.30	0.28 (0.0001)	-0.06	-0.18
	2004/05	189	2.90	0.80	8.90
Cd in urine (μg/L)	2003/04	201	0.60	0.15	2.15	0.48 (< 0.0001)	0.44	0.34
	2004/05	189	0.70	0.27	1.91
Creatinine in morning urine (g/L)	2003/04	201	0.72	0.15	1.80	-0.06 (0.40)	-0.47	-0.56
	2004/05	189	0.75	0.10	1.95
Pb in blood (μg/L)	2003/04	201	90.90	47.10	213.00	0.70 (< 0.0001)	0.69	0.62
	2004/05	189	85.00	39.10	203.00
Se in serum (μg/L)	2003/04	201	56.90	36.00	78.50	0.45 (< 0.0001)	0.17	0.05
	2004/05	189	72.10	46.40	95.70

The intraclass correlation coefficient (ICC) is the between- subject minus the within- subject variance as a ratio to the sum of the two variances. A positive value of, for instance, 0.60 indicates that 60% of the variation is due to between-subject and 40% due to within-subject variance. ICC can become negative when the within-subject variance exceeds the between-subject variance.

ISSN: 1476-069X