Table 2.
Vocabulary and cognitive level
| Variable | AU30 | DS30 | TD18 | χ2 | p |
|---|---|---|---|---|---|
| CDI | 23 (5–165) | 22 (9–59) | 53 (34–82) | 7.0 | .030 |
| Visual reception | 23 (18–25) | 20 (18–25) | 21 (20–23) | 3.3 | .194 |
| Fine motor | 22 (19–26) | 20 (18–22) | 20 (19–21) | 5.8 | .055 |
| Receptive language | 15 (13–27) | 14 (13–20) | 20 (18–23) | 11.2 | .004 |
| Expressive language | 16 (13–24) | 15 (14–17) | 18 (17–19) | 20.1 | < .001 |
| Mullen composite | 52 (49–62) | 55 (49–63) | 107 (98–118) | 70.2 | < .001 |
AU autism, DS Down syndrome, and TD typical development group; subscripts refer to average age (in months) at observation. Scores are medians (with 25th to 75th percentiles in parentheses). Scores in the first row are the median number of words reported by parents on the CDI; in rows 2–5, children’s median raw scores on the respective subtests of the Mullen Scales of Early Learning; and in the last row, children’s median total composite standard score on the Mullen Scales of Early Learning. Medians and not means are reported because the standardized skew exceeded 3 for the CDI, fine motor, and expressive language scores. For the CDI, n = 23, 29, and 56 for AU, DS, and TD groups, respectively; ns are the same for the other variables except n = 21 for AU. χ2 is per a Kruskal–Wallis test of group differences, df = 2