Table 4:

Stratum-specific associations between maternal persistent organic pollutant levels (>75^th percentile) and autism among offspring

	N Cases1	N Controls1	OR (95% CI)2	P	P-Int3
p,p'-DDE
Sex
Male	605	601	1.35 (1.02–1.80)	0.04	0.70
Female	172	172	1.19 (0.67–2.13)	0.55
Intellectual disability in the case
Yes	218	216	2.21 (1.32–3.69)	0.002	0.04
No	559	557	1.22 (0.88–1.69)	0.18
Total PCBs
Sex
Male	605	601	0.95 (0.70–1.27)	0.72	1.0
Female	172	172	0.95 (0.54–1.67)	0.85
Intellectual disability in the case
Yes	218	216	0.97 (0.60–1.56)	0.88	0.93
No	559	557	0.94 (0.69–1.28)	0.70

¹Number of subjects in each group with complete information for covariates (information on maternal parity was missing for 6 subjects)

²Adjusted for maternal age, parity, and maternal history of psychiatric disorder (see definition in Table 1)

³P-value for the difference in odds ratios between strata