Factors Affecting Age at Initial Autism Spectrum Disorder Diagnosis in a National Survey

Table 2

Multivariate linear regression of factors affecting log-transformed age at first parent concern (AOC) among 6214 individuals with ASD.

Parameter	Raw coefficient	Converted average difference in AOC compared with reference group (in mo)*	95% CI (in mo)		𝑃
Female gender	−0.08	−0.78	−1.33	−0.21	.009
Race
White	REF
Black/African-American	0.17	1.94	0.36	3.77	.015
Multiracial	−0.07	−0.74	−1.77	0.45	—
Other	0.04	0.38	−0.72	1.60	—
Hispanic Ethnicity	0.14	1.56	0.58	2.63	.001
Initial diagnosis
Autistic disorder	REF
PDD-NOS^a	0.05	0.55	−0.03	1.15	.060
Asperger Syndrome	0.25	2.93	2.00	3.95	< .001
Other ASD	−0.01	−0.08	−0.75	0.66	—
Presence of ID^b	−0.13	−1.27	−1.79	−0.72	< .001
Firstborn	0.10	1.03	0.54	1.56	< .001
High risk^c	−0.32	−2.82	−3.35	−2.25	< .001
History of autistic regression	0.06	0.58	0.03	1.18	.042

Adjusted by age.
Note —: 𝑃>.05, statistical nonsignificance.
^aPDD-NOS: Pervasive Developmental Disorder-Not Otherwise Specified.
^bID: Intellectual disability/mental retardation.
^cHigh risk: history of prematurity and/or seizures and/or cerebral palsy.