Table 2.

Prenatal specific-gravity-corrected organophosphate ester metabolite distribution in the nested study population within the Norwegian mother, father, and child cohort study, 2004–2008.^a

Exposure	Geometric mean (SD)b	Min	25%	50%	75%	Max	LOD	%≥LOD	LOQ	%≥LOQ
DPhP (ng/mL)							0.03		0.10
Preschool ADHD (N = 262)	0.49 (2.94)	<LOD	0.30	0.50	0.95	38.14		96.6%		92.4%
Typically developing (N = 78)	0.45 (3.45)	<LOD	0.20	0.44	0.82	16.17		97.4%		93.6%
Weighted population (N = 310)	0.45 (3.24)	<LOD	0.21	0.44	0.82	38.14		97.8%		92.5%
DnBP (ng/mL)							0.07		0.20
Preschool ADHD (N = 262)	0.27 (2.18)	<LOD	0.18	0.26	0.38	11.20		95.4%		67.6%
Typically developing (N = 78)	0.20 (2.06)	<LOD	0.14	0.22	0.35	0.67		87.2%		53.9%
Weighted population (N = 310)	0.23 (2.06)	<LOD	0.15	0.23	0.37	11.20		89.5%		59.5%
BBOEP (ng/mL)							0.07		0.20
Preschool ADHD (N = 262)	0.08 (2.00)	<LOD	<LOD	<LOD	0.14	0.86		44.7%		13.0%
Typically developing (N = 78)	0.09 (2.17)	<LOD	<LOD	<LOD	0.15	1.07		47.4%		19.2%
Weighted population (N = 310)	0.09 (2.08)	<LOD	<LOD	<LOD	0.15	1.07		46.2%		17.03%
BDCIPP (ng/mL)							0.17		0.50
Preschool ADHD (N = 262)	0.17 (2.42)	<LOD	<LOD	<LOD	<LOD	17.24		21.0%		11.1%
Typically developing (N = 78)	0.17 (2.00)	<LOD	<LOD	<LOD	0.18	2.67		25.6%		10.3%
Weighted population (N = 310)	0.16 (1.91)	<LOD	<LOD	<LOD	<LOD	17.24		23.6%		9.75%

Concentrations were expressed to three significant digits.

Weighted population was created using inverse probability of selection weights to account for oversampling of ADHD cases.

^aStudy enrollment occurred through January 2008; however, no study participants in this subpopulation were enrolled in January 2008.

^bVariables below the LOD were imputed using LOD/s.

min indicates minimum; max, maximum; ng/mL, nanograms per milliliter.