Table 4. Multivariate linear regression models for reported concern, ASD diagnosis, and first services, including parental concerns.

Age Outcome	Reported Concern	ASD Diagnosis	First Services
	β̂ (95% CI)	β̂ (95% CI)	β̂ (95% CI)
Parental Concerns
Verbal Communication	-0.79*** (-1.21, -0.38)	-1.71** (-2.69, -0.73)	-0.58* (-1.11, -0.04)
Behavioral Difficulties	1.04** (0.45, 1.64)	0.66 (-0.23, 1.55)	-0.05 (-0.77, 0.68)
Motor Problems	-0.14 (-0.48, 0.19)	0.31 (-0.22, 0.83)	-0.09 (-0.48, 0.29)
Nonverbal Communication	-0.06 (-0.51, 0.39)	-0.91* (-1.66, -0.17)	-0.17 (-0.60, 0.27)
Learning Difficulties	0.90*** (0.43, 1.38)	0.07 (-0.60, 0.73)	-0.11 (-0.64, 0.43)
Unusual Gestures/Movements	0.24 (-0.12, 0.59)	-1.26*** (-1.78, -0.74)	-0.34 (-0.73, 0.05)
Medical Problems	-0.24 (-0.75, 0.26)	0.48 (-0.09, 1.05)	0.11 (-0.31, 0.53)

Notes.

^*p<.05

^**p<.01

^***p<.001

ASD = autism spectrum disorder; ID = intellectual disability

All models are adjusted for child and household characteristics and whether the parent talked to the child's school regarding concerns about the child's development. Child characteristics include child's age, gender, race/ethnicity, the presence of younger or older biological siblings and current intellectual disability diagnosis. Household characteristics include federal poverty level percentage, highest educational attainment of household members, and family structure (two biological/adoptive/step-parents vs. all other family structures). Age of ASD diagnosis and first services were additionally adjusted by age of reported parental concern.