Table 2. Poisson Regression Model for aPR With a Robust Error Variance Using Multiple Imputation Chained Equations for Missing Data.
| Characteristic | aPR (95% CI) | P value |
|---|---|---|
| ASD status | ||
| Age, y | ||
| 5-9 | 1 [Reference] | NA |
| 10-14 | 1.19 (1.18-1.21) | <.001 |
| 15-19 | 1.21 (1.19-1.23) | <.001 |
| Sex | ||
| Female | 1 [Reference] | NA |
| Male | 4.39 (4.33-4.45) | <.001 |
| Race/ethnicity | ||
| White | 1 [Reference] | NA |
| Asian | 0.83 (0.81-0.85) | <.001 |
| Black | 1.26 (1.23-1.29) | <.001 |
| Chinese | 1.38 (1.26-1.50) | <.001 |
| Roma/Irish Traveler | 0.42 (0.36-0.48) | <.001 |
| Mixed | 1.02 (1.00-1.05) | .055 |
| Other | 0.92 (0.87-0.97) | .001 |
| Unclassified | 1.09 (1.03-1.15) | .001 |
| Eligible for FSM ever | ||
| No | 1 [Reference] | NA |
| Yes | 1.61 (1.59-1.63) | <.001 |
| Language at home | ||
| English | 1 [Reference] | NA |
| Other | 0.64 (0.63-0.65) | <.001 |
| Unknown | 0.77 (0.67-0.89) | <.001 |
| ASD EHCP | ||
| Age, y | ||
| 5-9 | 1 [Reference] | NA |
| 10-14 | 1.18 (1.16-1.20) | <.001 |
| 15-19 | 1.44 (1.40-1.47) | <.001 |
| Sex | ||
| Female | 1 [Reference] | NA |
| Male | 4.94 (4.85-5.04) | <.001 |
| Race/ethnicity | ||
| White | 1 [Reference] | NA |
| Asian | 1.02 (0.99-1.06) | .14 |
| Black | 1.68 (1.64-1.73) | <.001 |
| Chinese | 1.73 (1.56-1.92) | <.001 |
| Roma/Irish Traveler | 0.53 (0.45-0.63) | <.001 |
| Mixed | 1.14 (1.11-1.18) | <.001 |
| Other | 1.11 (1.05-1.19) | .001 |
| Unclassified | 1.26 (1.18-1.34) | <.001 |
| Eligible for FSM ever | ||
| No | 1 [Reference] | NA |
| Yes | 1.71 (1.68-1.74) | <.001 |
| Language at home | ||
| English | 1 [Reference] | NA |
| Other | 0.70 (0.68-0.72) | <.001 |
| Unclassified | 0.64 (0.53-0.78) | <.001 |
| ASD support | ||
| Age, y | ||
| 5-9 | 1 [Reference] | NA |
| 10-14 | 1.20 (1.18-1.22) | <.001 |
| 15-19 | 0.92 (0.89-0.95) | <.001 |
| Sex | ||
| Female | 1 [Reference] | NA |
| Male | 3.77 (3.69-3.85) | <.001 |
| Race/ethnicity | ||
| White | 1 [Reference] | NA |
| Asian | 0.58 (0.55-0.60) | <.001 |
| Black | 0.72 (0.68-0.75) | <.001 |
| Chinese | 0.93 (0.79-1.10) | .39 |
| Roma/Irish Traveler | 0.27 (0.20-0.35) | <.001 |
| Mixed | 0.88 (0.85-0.91) | <.001 |
| Other | 0.66 (0.60-0.73) | <.001 |
| Unclassified | 0.89 (0.81-0.97) | .006 |
| Eligible for FSM ever | ||
| No | 1 [Reference] | NA |
| Yes | 1.49 (1.46-1.51) | <.001 |
| Language at home | ||
| English | 1 [Reference] | NA |
| Other | 0.54 (0.52-0.56) | <.001 |
| Unclassified | 1.01 (0.82-1.25) | .91 |
| ASD and secondary SEND | ||
| Age, y | ||
| 5-9 | 1 [Reference] | NA |
| 10-14 | 1.11 (1.09-1.13) | <.001 |
| 15-19 | 1.01 (1.98-1.03) | .48 |
| Sex | ||
| Female | 1 [Reference] | NA |
| Male | 4.47 (4.38-4.56) | <.001 |
| Race/ethnicity | ||
| White | 1 [Reference] | NA |
| Asian | 0.82 (0.79-0.85) | <.001 |
| Black | 1.22 (1.18-1.26) | <.001 |
| Chinese | 1.41 (1.25-1.58) | <.001 |
| Roma/Irish Traveler | 0.36 (0.29-0.44) | <.001 |
| Mixed | 1.00 (0.96-1.03) | .89 |
| Other | 0.94 (0.88-1.01) | .11 |
| Unclassified | 1.12 (1.04-1.20) | .002 |
| Eligible for FSM ever | ||
| No | 1 [Reference] | NA |
| Yes | 1.43 (1.40-1.45) | <.001 |
| Language at home | ||
| English | 1 [Reference] | NA |
| Other | 0.62 (0.60-0.63) | <.001 |
| Unclassified | 0.99 (0.83-1.18) | .90 |
Abbreviations: aPR, adjusted prevalence ratio; ASD, autism spectrum disorder; EHCP, Education, Health and Care Plan; FSM, Free School Meals program; NA, not applicable; SEND, Special Educational Needs and Disability.