Table 1.
Characteristics of children aged 8 years with autism (N = 20 135), by profound autism status—ADDM Network, 15 sites, United States, 2000–2016a
| Characteristic | Total,b no. (%) | Non–profound autism,c % (n = 14 755) | Profound autism,d % (n = 5380) | Prevalence ratio (95% CI) |
|---|---|---|---|---|
|
| ||||
| Total | 20 135 (100.0) | 73.3 | 26.7 | |
| Sex | ||||
| Male | 16 524 (82.1) | 74.4 | 25.6 | 1 [Reference] |
| Female | 3611 (17.9) | 68.1 | 31.9 | 1.25 (1.18–1.32) |
| Race and ethnicity | ||||
| Non-Hispanic White | 11 643 (57.8) | 78.7 | 21.3 | 1 [Reference] |
| Non-Hispanic Asian/Native Hawaiian/Other Pacific Islander | 764 (3.8) | 67.1 | 32.9 | 1.55 (1.38–1.73) |
| Non-Hispanic American Indian/Alaska Native | 110 (0.5) | 71.8 | 28.2 | 1.33 (0.97–1.82) |
| Non-Hispanic Black | 4312 (21.4) | 62.6 | 37.4 | 1.76 (1.67–1.86) |
| Hispanic | 2829 (14.1) | 68.1 | 31.9 | 1.50 (1.40–1.61) |
| Non-Hispanic multiple races/other | 479 (2.4) | 77.6 | 22.4 | 1.05 (0.88–1.26) |
| ADDM study year | ||||
| 2000 | 1246 (6.2) | 59.5 | 40.5 | 1 [Reference] |
| 2002 | 2366 (11.8) | 73.1 | 26.9 | 0.67 (0.60–0.74) |
| 2004 | 1151 (5.7) | 74.5 | 25.5 | 0.63 (0.55–0.72) |
| 2006 | 2286 (11.4) | 72.1 | 27.9 | 0.69 (0.62–0.76) |
| 2008 | 3216 (16.0) | 72.8 | 27.2 | 0.67 (0.61–0.74) |
| 2010 | 4975 (24.7) | 75.0 | 25.0 | 0.62 (0.57–0.68) |
| 2016 | 4895 (24.3) | 75.7 | 24.3 | 0.60 (0.55–0.66) |
| Site | ||||
| Colorado | 1130 (5.6) | 79.0 | 21.0 | 1 [Reference] |
| Utah | 683 (3.4) | 78.7 | 21.3 | 1.01 (0.83–1.23) |
| Maryland | 1722 (8.6) | 77.9 | 22.1 | 1.05 (0.90–1.23) |
| Minnesota | 313 (1.6) | 77.7 | 22.3 | 1.06 (0.83–1.35) |
| New Jersey | 2486 (12.3) | 76.8 | 23.2 | 1.10 (0.96–1.27) |
| Arizona | 2530 (12.6) | 75.4 | 24.6 | 1.17 (1.02–1.34) |
| Tennessee | 405 (2.0) | 74.8 | 25.2 | 1.20 (0.97–1.48) |
| North Carolina | 2209 (11.0) | 72.8 | 27.2 | 1.30 (1.13–1.49) |
| West Virginia | 257 (1.3) | 72.2 | 27.8 | 1.33 (1.03–1.70) |
| Wisconsin | 1702 (8.5) | 71.5 | 28.5 | 1.36 (1.17–1.57) |
| Arkansas | 1514 (7.5) | 70.5 | 29.5 | 1.41 (1.22–1.63) |
| Georgia | 3306 (16.4) | 70.2 | 29.8 | 1.42 (1.24–1.62) |
| Alabama | 678 (3.4) | 68.6 | 31.4 | 1.50 (1.26–1.77) |
| Florida | 327 (1.6) | 66.3 | 33.7 | 1.60 (1.31–1.97) |
| South Carolina | 873 (4.3) | 61.7 | 38.3 | 1.82 (1.57–2.12) |
| Associated behavioral and clinical features Self-injurious behaviors |
||||
| No | 14 491 (72.0) | 76.4 | 23.6 | 1 [Reference] |
| Yes | 5645 (28.0) | 65.2 | 34.8 | 1.48 (1.41–1.55) |
| Aggressive behaviors | ||||
| No | 9722 (48.3) | 73.8 | 26.2 | 1 [Reference] |
| Yes | 10 413 (51.7) | 72.8 | 27.2 | 1.04 (0.99–1.09) |
| Seizure or seizure-like behaviors | ||||
| No | 15 058 (74.8) | 75.3 | 24.7 | 1 [Reference] |
| Yes | 5077 (25.2) | 67.2 | 32.8 | 1.33 (1.26–1.40) |
| Adaptive functioning score | ||||
| ≤70 | 11 015 (54.7) | 61.2 | 38.8 | 1 [Reference] |
| 71–85 | 6155 (30.6) | 85.8 | 14.2 | 0.37 (0.34–0.40) |
| >85 | 2965 (14.7) | 92.0 | 8.0 | 0.21 (0.18–0.24) |
| Socioeconomic statuse | ||||
| Education, tertile | ||||
| Lowest | 5259 (26.1) | 66.0 | 34.0 | 1 [Reference] |
| Middle | 7170 (35.6) | 73.0 | 27.0 | 0.79 (0.75–0.84) |
| Highest | 7705 (38.3) | 78.5 | 21.5 | 0.63 (0.60–0.67) |
| Poverty, tertile | ||||
| Highest | 5487 (27.3) | 65.9 | 34.1 | 1 [Reference] |
| Middle | 7071 (35.1) | 73.1 | 26.9 | 0.79 (0.75–0.84) |
| Lowest | 7578 (37.6) | 78.8 | 21.2 | 0.62 (0.58–0.66) |
| Median annual household income, tertile | ||||
| Lowest | 5365 (26.6) | 65.8 | 34.2 | 1 [Reference] |
| Middle | 6980 (34.7) | 72.6 | 27.4 | 0.80 (0.76–0.85) |
| Highest | 7790 (38.7) | 79.1 | 20.9 | 0.61 (0.57–0.65) |
| Maternal education status | ||||
| ≤High school diploma | 8711 (43.3) | 69.2 | 30.8 | 1 [Reference] |
| ≤Bachelor’s degree | 9106 (45.2) | 75.6 | 24.4 | 0.79 (0.75–0.84) |
| >Bachelor’s degree | 2319 (11.5) | 79.7 | 20.3 | 0.66 (0.59–0.74) |
| Birth characteristics | ||||
| Pretermf | ||||
| No | 16 986 (84.4) | 73.8 | 26.2 | 1 [Reference] |
| Yes | 3149 (15.6) | 70.7 | 29.3 | 1.12 (1.02–1.22) |
| Low birth weightg | ||||
| No | 17 730 (88.1) | 74.2 | 25.8 | 1 [Reference] |
| Yes | 2406 (11.9) | 66.5 | 33.5 | 1.30 (1.20–1.41) |
| Special education eligibilityh | ||||
| Autism | 8452 (42.0) | 69.8 | 30.2 | 1 [Reference] |
| Developmental delay/preschool | 634 (3.1) | 74.1 | 25.9 | 0.86 (0.75–0.99) |
| Emotional disturbance | 502 (2.5) | 94.1 | 5.9 | 0.19 (0.14–0.28) |
| Hearing or visual impairments | 35 (0.2) | 63.4 | 36.6 | 1.21 (0.76–1.91) |
| Intellectual disability | 1025 (5.1) | 43.3 | 56.7 | 1.88 (1.76–2.00) |
| Multiple disabilities | 478 (2.4) | 50.6 | 49.4 | 1.63 (1.47–1.81) |
| Orthopedic impairments | 71 (0.4) | 79.0 | 21.0 | 0.69 (0.43–1.11) |
| Unknown/otheri | 6739 (33.5) | 76.7 | 23.3 | 0.77 (0.73–0.82) |
| Other health impairments | 1271 (6.3) | 91.1 | 8.9 | 0.29 (0.25–0.35) |
| Specific learning disabilities | 916 (4.5) | 89.9 | 10.1 | 0.33 (0.27–0.41) |
| Traumatic brain injury | 12 (0.1) | 37.5 | 62.5 | 2.06 (1.30–3.28) |
Data source: Autism and Developmental Disabilities Monitoring (ADDM) Network.8
Sample sizes may not sum to 20 135 because of rounding the average number in each group for the 20 imputed datasets.
Non–profound autism was defined as children with autism who did not meet the profound autism criteria.
Profound autism was defined as children with autism who were either nonverbal or minimally verbal or had an (intelligence quotient) IQ <50.
Socioeconomic status was based on census tract–level indicator rank values. Within each site, census tracts were ranked among all other census tracts in the study population and divided into tertiles, so an approximately equal proportion of the population was categorized into each tertile. The 3 socioeconomic indicators were (1) education: percentage of population aged ≥25 years with ≥high school diploma or General Educational Development (GED); (2) poverty: percentage of families with children aged <19 years living below the federal poverty level; and (3) median annual household income: percentile rank for census tract.
Born at <37 weeks gestation.
Born weighing <2500 g.
Special education categories were based on the most recent special education eligibility classification; if a child was served under >1 eligibility, the child would be classified as having “multiple disabilities.”
Other/unknown means either Individualized Educational Program eligibility information was not collected or the eligibility listed was not one of the choices.