Early childhood exposure to environmental phenols and parabens, phthalates, organophosphate pesticides, and trace elements in association with attention deficit hyperactivity disorder (ADHD) symptoms in the CHARGE study

Table 2 Covariate-adjusted associations between mixtures and ABC ADHD/noncompliance subscale and two subdomain scores among all children and stratified by diagnostic group

Outcome	Mixture	All (n = 549)			ASD (n = 225)
Outcome	Mixture	Median CR^a	2.5 PCT	97.5 PCT	Median CR ^b	2.5 PCT	97.5 PCT
ADHD/noncompliance	Phenols/parabens	0.92	0.81	1.04	1.12	0.96	1.28
	Phthalate metabolites	1.10	1.00	1.21	1.15	1.06	1.26
	Pesticide metabolites	1.04	0.95	1.14	0.95	0.87	1.01
	Trace elements	0.97	0.87	1.10	1.04	0.89	1.15
	Total mixture	1.02	0.87	1.21	1.15	1.01	1.29
Hyperactivity/impulsivity	Phenols/parabens	0.92	0.75	1.07	1.07	0.92	1.25
	Phthalate metabolites	1.09	1.00	1.25	1.22	1.07	1.37
	Pesticide metabolites	1.01	0.91	1.11	0.98	0.88	1.04
	Trace elements	0.98	0.86	1.13	1.04	0.87	1.21
	Total mixture	1.03	0.84	1.18	1.21	1.04	1.36
Inattention	Phenols/parabens	0.97	0.85	1.09	1.11	0.97	1.25
	Phthalate metabolites	1.05	0.97	1.12	1.10	1.02	1.20
	Pesticide metabolites	0.98	0.93	1.07	0.99	0.91	1.08
	Trace elements	1.01	0.93	1.10	1.01	0.92	1.12
	Total mixture	0.98	0.85	1.08	1.11	0.96	1.26
		TD (n = 236) ^c			DD (n = 88) ^c
		Median CR ^b	2.5 PCT	97.5 PCT	Median CR ^b	2.5 PCT	97.5 PCT
ADHD/noncompliance	Total mixture	1.01	0.69	1.51	0.75	0.47	1.18
Hyperactivity/impulsivity	Total mixture	1.05	0.61	1.40	0.75	0.48	1.40
Inattention	Total mixture	1.00	0.59	1.46	0.81	0.53	1.12

ABC Aberrant Behavior Checklist, ADHD Attention-deficit/hyperactivity disorder, ASD Autism spectrum disorder, CHARGE Childhood Autism Risks from Genetics and Environment, CR Count ratio, DD Developmental delay, PCT percentile, TD Typical development, WQS Weighted quantile sum
^aWQS regression models were adjusted for CHARGE case-control study frequency matching factors (child’s sex, age at assessment, and recruitment regional center), child’s birth year and race/ethnicity, parity, parental education, maternal metabolic conditions, and diagnosis
^bWQS regression models were adjusted for CHARGE case-control study frequency matching factors (child’s sex, age at assessment, and recruitment regional center), child’s birth year and race/ethnicity, parity, parental education, and maternal metabolic conditions
^cRepeated holdout WQS regression models of each chemical class did not converge among children with TD or DD; therefore, the results were not presented

ISSN: 1476-069X