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. 2018 Nov 16;65(13):1–23. doi: 10.15585/mmwr.ss6513a1

TABLE 5. Median age of earliest known autism spectrum disorder diagnosis and number and proportion within each diagnostic subtype — Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2012.

Site ASD subtype
Autistic disorder
ASD-NOS/PDD-NOS
Asperger disorder
Any ASD subtype
Median age (mos) No. (%) Median age (mos) No. (%) Median age (mos) No. (%) Median age (mos) No. (%)
Arizona
50.0
253 (74.4)
64.0
72 (21.2)
77.0
15 (4.4)
55.0
340 (68.8)
Arkansas
57.0
73 (76.0)
60.0
12 (12.5)
84.0
11 (11.5)
60.0
96 (76.8)
Colorado
48.0
184 (66.2)
59.0
55 (19.8)
80.0
39 (14.0)
55.0
278 (63.8)
Georgia
47.5
261 (48.0)
51.0
230 (42.2)
71.0
53 (9.7)
51.0
544 (70.6)
Maryland*
41.0
56 (40.6)
48.0
79 (57.2)
44.0
3 (2.2)
45.5
138 (79.3)
Maryland
46.5
44 (35.5)
44.5
72 (58.1)
74.0
8 (6.5)
48.0
124 (83.8)
Missouri
50.0
67 (26.0)
51.0
145 (56.2)
77.5
46 (17.8)
58.0
258 (86.0)
New Jersey
45.0
193 (29.7)
43.0
380 (58.5)
74.0
77 (11.8)
47.0
650 (80.9)
North Carolina
36.5
206 (53.6)
55.0
155 (40.4)
72.0
23 (6.0)
48.0
384 (58.8)
South Carolina
45.0
143 (65.6)
58.5
68 (31.2)
74.0
7 (3.2)
48.0
218 (72.2)
Utah
45.0
114 (31.7)
48.0
178 (49.4)
63.5
68 (18.9)
50.0
360 (83.5)
Wisconsin
45.5
106 (34.8)
49.0
173 (56.7)
74.0
26 (8.5)
50.0
305 (79.4)
Total 46.0 1,700 (46.0) 49.0 1,619 (43.8) 74.0 376 (10.2) 50.0 3,695 (73.6)

Abbreviations: ASD = autism spectrum disorder; ASD-NOS = autism spectrum disorder–not otherwise specified; PDD-NOS = pervasive developmental disorder–not otherwise specified.

*Education and health records review area.

Health records only review area.