Table 1.

Descriptive Data for Cotinine Exposure Across Time Points

Raw cotinine values (ng/mL)
	N	Median	Range	25%	75%
6 mo	1118	1.61	0–215.12	0.47	5.84
15 mo	935	1.83	0–90.29	0.47	5.50
24 mo	899	1.66	0–559.58	0.41	5.32
48 mo	932	0.69	0–76.22	0.20	3.18
Ordinal classification of exposure
	Low (<0.45 ng/mL)		Moderate (0.45–12 ng/mL)		High (≥12 ng/mL)
6 mo	24%		64%		12%
15 mo	24%		64%		12%
24 mo	26%		64%		10%
48 mo	41%		54%		5%