TABLE 2.

Maternal Serum Cotinine Levels by Deciles in Patients With ADHD and Matched Controls

Maternal Cotinine by Deciles,a %	Range, ng/mL	Patients (n = 1079)		Controls (n = 1079)
		n	%	n	%
<10	<0.008	67	6.2	107	9.9
10–19	0.009–0.011	73	6.8	108	10.0
20–29	0.012–0.014	66	6.1	107	9.9
30–39	0.015–0.019	89	8.2	109	10.1
40–49	0.020–0.024	96	8.9	112	10.4
50–59	0.025–0.033	99	9.2	104	9.6
60–69	0.034–0.052	88	8.2	108	10.0
70–79	0.053–0.165	118	10.9	108	10.0
80–89	0.166–41.08	139	12.9	108	10.0
≥90	≥41.08	244	22.6	108	10.0

^aThe cut points for deciles are based on maternal cotinine levels in the control group.