Table 2.

Hazard ratios for time from first evaluation noting developmental concern to time to first autism spectrum diagnosis comparing children of mothers of advanced maternal age to child whose mothers were not of advanced maternal among children with autism spectrum disorder identified by the Autism and Developmental Disabilities Monitoring Network in 2008, 2010, and 2012

	Age at first evaluation that noted developmental concern (Months)		Time from evaluation to ASD diagnosis (Months)
	Hazard ratio	95% CI	Hazard ratio	95% CI
Unadjusted	1.12*	1.06, 1.18	1.08*	1.02, 1.14
Adjusted	1.02	0.96, 1.08	1.03	0.96, 1.10

^*Statistically significant at an alpha=0.05 level

Advanced maternal age defined as childbirth at ≥35 years of age

ASD autism spectrum disorder

CI confidence interval

Adjusted model controlled for maternal race/ethnicity, maternal education, study site, child year of birth, child gestational age, paternal age, parity, birth order, and record type with multiple imputation to account for missing paternal age data