Table 2.

Age of autism spectrum disorder identification and age of first comprehensive evaluation by record Source, Autism and Developmental Disabilities Monitoring Network, Study Year 2016

	Age in months of first ASD identificationa						p value	Age in months of first comprehensive evaluationa						p value
	Records from health sources only		Records from health and education sources		Records from education sources only			Records from health sources only		Records from health and education sources		Records from education sources only
	N	Median	N	Median	N	Median		N	Median	N	Median	N	Median
Allb,c	69	44	687	50	163	69	< .01	125	31	757	35	257	53	< .01
Sex
Maleb,c	48	44	587	50	137	70	< .01	87	30	643	36	211	53	< .01
Femaleb,c	21	47	100	49	26	63	< .01	38	31	114	32	46	54	< .01
Race/Ethnicity
White, Non-Hispanicb,c	40	39	293	53	60	68	< .01	76	28	321	34	95	55	< .01
Black, Non-Hispanicc,d	18	58	172	49	45	63	< .01	25	50	194	37	76	47	< .01
Asian or Pacific Islander, Non-Hispanic b,c	2	31	55	49	15	64	< .01	5	21	60	39	22	52	< .01
Hispanic, regardless of raceb,c	7	38	129	51	35	82	< .01	16	29	139	37	47	61	< .01
Presence of ID
Nob,c	23	56	395	55	106	74	< .01	44	30	444	38	175	56	< .01
Yesc,e	20	29	232	44	37	64	< .01	43	25	248	32	59	46	< .01
Missingb,c	26	47	60	44	20	54	.06	38	42	65	41	23	53	.09
Level of impairment associated with ASD
Mildb,c	19	51	220	59	65	77	< .01	50	34	271	38	128	57	< .01
Moderateb,c	36	39	355	50	84	68	< .01	59	28	372	35	110	52	< .01
Severe	14	47	112	39	14	51	.16	16	30	114	33	19	46	.46

^aRestricted to children with a linked birth certificate to indicate that they were born in state

^bp < 0.05 for health only and education only records

^cp < 0.05 for health and education and education only records

^dp < 0.05 for health only and health and education

^eDefined as IQ≤70 or an examiner’s statement indicating the presence of intellectual disability