Table I.
Total Sample Characteristics by Expressive Language Level and Diagnosis
| Phrase-speech | Single words | Nonverbal | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ASD diagnoses | Other diagnoses | No diagnoses | ASD diagnoses | Other diagnoses | ASD diagnoses | Other diagnoses | ||||||||
| N | M (SD) | N | M (SD) | N | M (SD) | N | M (SD) | N | M (SD) | N | M (SD) | N | M (SD) | |
| Age in months | 35 | 41.2 (2.6) | 231 | 41.5 (2.1) | 294 | 42.1 (2.2) | 20 | 41.1 (3.3) | 58 | 41.0 (2.4) | 11 | 41.4 (3.2) | 14 | 41.8 (2.6) |
| Male sex [%] | 32 | [91.4] | 167 | [72.3] | 165 | [56.1] | 17 | [85.0] | 48 | [82.8] | 6 | [54.5] | 10 | [71.4] |
| IQ | 34 | 81.3 (20.5) | 230 | 92.5 (15.0) | 294 | 103.6 (12.2) | 18 | 64.0 (19.9) | 57 | 72.0 (15.9) | 11 | 37.7 (11.2) | 13 | 52.7 (19.9) |
| Language age | 33 | 29.5 (7.6) | 222 | 33.2 (9.1) | 283 | 43.2 (8.9) | 20 | 16.9 (3.4) | 58 | 18.8 (4.4) | 11 | 7.5 (4.3) | 14 | 11.9 (4.6) |
| Behavior problems (item mean) | ||||||||||||||
| Parent-reported | 35 | 0.6 (0.2) | 223 | 0.6 (0.3) | 286 | 0.5 (0.2) | 20 | 0.8 (0.3) | 56 | 0.6 (0.3) | 11 | 0.6 (0.2) | 13 | 0.5 (0.2) |
| Clinician-observed | 35 | 0.5 (0.4) | 231 | 0.2 (0.3) | 294 | 0.2 (0.2) | 20 | 0.4 (0.4) | 58 | 0.3 (0.4) | 11 | 0.5 (0.5) | 14 | 0.2 (0.4) |
| ADOS-CSS | 35 | 5.9 (2.0) | 231 | 1.8 (1.6) | 294 | 1.3 (1.0) | 20 | 6.1 (2.4) | 58 | 2.3 (1.7) | 11 | 7.8 (1.5) | 14 | 2.6 (2.3) |
| ADI-R (full diagnostic algorithm) | 35 | 13.6 (7.0) | 231 | 4.0 (4.1) | 294 | 1.7 (2.7) | 20 | 12.2 (5.3) | 58 | 4.8 (4.8) | 11 | 15.1 (7.0) | 14 | 5.0 (4.3) |
| ADI-R (common items) Identification route, n [%] | 35 | 7.1 (4.1) | 231 | 1.9 (2.2) | 294 | 1.0 (1.6) | 20 | 8.1 (3.5) | 58 | 3.3 (3.1) | 11 | 11.6 (5.2) | 14 | 4.4 (3.7) |
| Parental concern for ASD | 13 | [37%] | 14 | [6%] | 2 | [1%] | 9 | [45%] | 4 | [7%] | 4 | [36%] | 2 | [14%] |
| Parent-reported ASD signs without concern about ASD | 21 | [60%] | 187 | [81%] | 112 | [38%] | 11 | [55%] | 52 | [90%] | 5 | [46%] | 12 | [86%] |
| Controls/other | 1 | [3%] | 30 | [13%] | 180 | [61%] | 0 | 2 | [3%] | 2 | [18%] | 0 | ||
| Maternal education ≤12 years, n [%]a | 9 | [26%] | 73 | [33%] | 79 | [28%] | 10 | [50%] | 23 | [40%] | 3 | [38%] | 5 | [39%] |
Note. Language level strata are based on ADI-R item 30 (overall level of language).
a
Missing on maternal education for n = 554, percentage of non-missing is reported.
ASD, autism spectrum disorder; ADOS-CSS, standardized comparison scores from the autism diagnostic observation schedule; ADI-R Toddler (common items), sum of the 10 ADI-R diagnostic items common across language levels (attention to voice, direct gaze, seeking to share enjoyment, range of facial expressions, appropriateness of social response, interest in children, response to approaches of children, hand and finger mannerisms, other complex mannerisms, unusual sensory interests).