Table 4.

Pair-wise comparisons of endotoxin concentrations at 1 and 6 months at each of the five home locations studied^*

	1-month values				6-month values
Location	n*	GM**	Ln mean**	Ln SD	n*	GM**	Ln mean**	Ln SD	p-Value†
Child's bed	262	2.36	0.86	1.41	262	3.74	1.32	1.45	0.001
Child's bedroom floor	143	12.18	2.50	1.42	143	10.59	2.36	1.45	0.268
Living room floor	335	19.69	2.98	1.29	335	16.95	2.83	1.32	0.079
Mother's bed	335	3.74	1.32	1.52	335	3.19	1.16	1.46	0.130
Mother's bedroom floor	335	14.88	2.70	1.34	335	12.68	2.54	1.45	0.072

^*Sample size is limited to homes with valid sample values at both 1 and 6 months for each location. The numbers for the child's floor exclude homes in which the child slept (or was sleeping) in the same room as the mother at either 1 or 6 months.

^**GM, geometric mean in endotoxin units (EU)/mg; Ln mean, natural logarithm of the mean concentrations of endotoxin expressed as EU/mg of dust; Ln SD, standard deviation of the log mean.

^†Wilcoxon matched-pairs signed-rank test.