Extended Data, Table 1. Subject demographics (including tests for group differences).
No significant group differences (between HR-ASD, HR-neg and LR) were observed in race/ethnicity, family income, maternal age at birth, infant birth weight, gestational age at birth, or age at visit. As expected based on the well-known disproportionately higher rates of ASD in males, the HR-ASD group contained significantly more males than the LR group (χ2 (2) = 15.7, p <.01). We also observed that the LR group had higher maternal education compared to the other two groups (χ2 (2) = 36.4, p <.01). As expected, based on the association between intellectual disability and ASD, the HR-ASD group had significantly lower Mullen and Vineland scores at 24 months than the other two groups. KEY: SD = standard deviation, % = percentage, Mullen ELC – Early Learning Composite standard score; Vineland ABC– Vineland Adaptive Behavior Composite standard score.
| LR (N=117) | HR-neg (N=248) | HR-ASD (N=70) | P | ||||
|---|---|---|---|---|---|---|---|
|
| |||||||
| N | (%) | N | (%) | N | (%) | ||
| Sex | <0.01 | ||||||
| Female | 48 | (41) | 106 | (43) | 12 | (17) | |
| Male | 69 | (59) | 142 | (57) | 58 | (83) | |
| Race | 0.14 | ||||||
| Non-white | 15 | (13) | 29 | (12) | 9 | (13) | |
| White | 102 | (87) | 213 | (86) | 61 | (87) | |
| Not reported | 0 | (0) | 6 | (2) | 0 | (0) | |
| Family Income | 0.13 | ||||||
| Not Answered | 5 | (4) | 20 | (8) | 1 | (2) | |
| <50K | 17 | (15) | 52 | (21) | 19 | (27) | |
| 50-75K | 27 | (23) | 42 | (17) | 17 | (24) | |
| 75-100K | 20 | (17) | 40 | (16) | 12 | (17) | |
| 100-150K | 29 | (25) | 50 | (20) | 12 | (17) | |
| >150K | 19 | (16) | 44 | (18) | 9 | (13) | |
| Mother's Highest Education | <0.01 | ||||||
| Not Answered | 0 | (0) | 8 | (3) | 0 | (0) | |
| No College | 16 | (14) | 75 | (30) | 29 | (41) | |
| College Degree | 47 | (40) | 108 | (44) | 25 | (36) | |
| Graduate Degree | 54 | (46) | 57 | (23) | 16 | (23) | |
|
| |||||||
| Mean | (SD) | Mean | (SD) | Mean | (SD) | ||
|
| |||||||
| Mother's Age at Child Birth | 0.99 | ||||||
| Years | 33.2 | (4.2) | 33.2 | (4.7) | 33.3 | (4.1) | |
| Birth Weight | 0.52 | ||||||
| Pounds (LB) | 8.0 | (1.0) | 7.9 | (1.0) | 7.9 | (1.3) | |
| Gestational Age at Birth | 0.30 | ||||||
| Weeks | 39.3 | (1.3) | 39.1 | (1.2) | 38.9 | (1.1) | |
| Age at Study Visit | |||||||
| 6 month visit | 6.7 | (0.7) | 6.6 | (0.7) | 6.6 | (0.7) | 0.54 |
| 12 month visit | 12.7 | (0.7) | 12.7 | (0.6) | 12.7 | (0.7) | 0.48 |
| 24 month visit | 24.6 | (0.8) | 24.7 | (0.9) | 24.6 | (0.6) | 0.59 |
| 24 month Behavioral Scores | |||||||
| Mullen ELC | 109.7 | (13.8) | 101.8 | (15.9) | 79.3 | (17.6) | 0.01 |
| Vineland ABC | 105.0 | (7.4) | 101.0 | (9.0) | 88.1 | (10.0) | <0.01 |