Table 2.
County and state characteristics and age of first autism spectrum disorder diagnosis in the Medicaid system for children younger than ten years (N=28,722)a
| Characteristic | Unadjusted age of first diagnosis (months) |
p | Adjusted age of first diagnosisb |
||
|---|---|---|---|---|---|
| Months | SE | p | |||
| County characteristic | |||||
| Median income ($) | .08 | .07 | |||
| 1st quartile (16,610–30,160) | 62.2 | 65.8 | .16 | ||
| 2nd quartile (30,164–34,892) | 62.7 | 64.1 | .99 | ||
| 3rd quartile (34,899–41,041) | 66.8 | 65.2 | .95 | ||
| 4th quartile (41,042–93,927) | 64.9 | 64.0 | .06 | ||
| Residents living in poverty (%) | <.001 | .03 | |||
| 1st quartile (2.3–9.6) | 65.8 | 66.1 | .13 | ||
| 2nd quartile (9.7–12.7) | 64.8 | 65.1 | .97 | ||
| 3rd quartile (12.8–16.8) | 67.8 | 65.3 | .97 | ||
| 4th quartile (16.9–40.7) | 60.8 | 62.7 | .16 | ||
| White residents (%) | .12 | .19 | |||
| 1st quartile (4.5–74.89) | 65.1 | 64.9 | .98 | ||
| 2nd quartile (74.94–90.01) | 63.8 | 64.2 | .93 | ||
| 3rd quartile (90.03–96.22) | 65.1 | 64.3 | .94 | ||
| 4th quartile (96.23–99.46) | 66.0 | 65.7 | .01 | ||
| County residents on Medicaid (%) | .003 | .36 | |||
| 1st quartile (3.28–28.53) | 65.7 | 65.3 | .05 | ||
| 2nd quartile (28.56–37.98) | 65.5 | 65.5 | .96 | ||
| 3rd quartile(38.00–48.95) | 66.6 | 64.5 | .92 | ||
| 4th quartile (48.98–89.26) | 61.4 | 64.0 | .99 | ||
| Per capita pediatricians (per 1,000) | .54 | .51 | |||
| None (0) | 65.0 | 65.2 | .03 | ||
| Low (.03–.318) | 65.1 | 64.9 | .92 | ||
| High (.319–3.71) | 64.8 | 64.3 | .93 | ||
| Per capita pediatric specialists (per 1,000) | .99 | .40 | |||
| None (0) | 64.4 | 64.5 | .91 | ||
| Any (.02–35.84) | 64.9 | 65.2 | .94 | ||
| Teacher-student ratio (prekindergarten | |||||
| through 12th grade) | .25 | .34 | |||
| 1st quartile (.028–.0617) | 66.4 | 64.3 | .94 | ||
| 2nd quartile (.0621–.0671) | 63.0 | 64.2 | .93 | ||
| 3rd quartile (.0676–.0735) | 63.9 | 65.2 | .93 | ||
| 4th quartile (.0741–.3704) | 64.1 | 65.5 | .01 | ||
| Expenditures per student ($) | .46 | .38 | |||
| 1st quartile (2,810–7,391) | 63.9 | 64.7 | .99 | ||
| 2nd quartile( 7,394–8,259) | 63.6 | 65.2 | .95 | ||
| 3rd quartile (8,260–9,589) | 64.7 | 65.2 | .93 | ||
| 4th quartile (9,594–67,898) | 66.3 | 64.1 | .95 | ||
| Non–English-speaking persons | .25 | .09 | |||
| 1st quartile (0–16) | 63.6 | 63.5 | .12 | ||
| 2nd quartile (17–50) | 65.6 | 65.6 | .00 | ||
| 3rd quartile (51–171) | 63.7 | 64.6 | .94 | ||
| 4th quartile (172–149,648) | 65.1 | 65.6 | .00 | ||
| Rural or urban | |||||
| County in metropolitan area of | |||||
| 1,000,000 or more (366 counties) | 66.1 | .04 | 65.7 | .01 | .05 |
| County in metropolitan area of fewer | |||||
| than 1,000,000 (632 counties) | 63.3 | 64.0 | .90 | ||
| Urban area population (1,146 counties) | 64.3 | 64.1 | .86 | ||
| Rural areas or areas < 2,500 | |||||
| urban population (278 counties) | 65.5 | 65.4 | .46 | ||
| State characteristic | |||||
| Children 0–5 years in early intervene tion (%) |
.30 | .13 | |||
| 1st quartile (2.14–3.53) | 64.0 | 65.3 | .52 | ||
| 2nd quartile (3.64–4.15) | 68.2 | 66.2 | .24 | ||
| 3rd quartile (4.17–5.37) | 64.5 | 65.2 | .24 | ||
| 4th quartile (5.60–8.39) | 62.1 | 62.5 | .31 | ||
| Percentage of poverty level required | |||||
| for State Children’s Health Insurance | |||||
| Program eligibility | .20 | .04 | |||
| Low (133%) | 63.1 | 63.0 | .99 | ||
| Middle (140%–185%) | 70.7 | 66.8 | .31 | ||
| High (200%–300%) | 64.6 | 64.6 | .35 | ||
a
Data are from January 1, 2002, to December 31, 2004.
b
Adjusted for individual-, county-, and state-level variables