Table 1.
Descriptive statistics
| Tot | C1 decreasing adaptive behaviour | C2 average/stable adaptive behaviour | C3 recovering adaptive behaviour | |||||
|---|---|---|---|---|---|---|---|---|
| Mean | SD | Mean | SD | Mean | SD | Mean | SD | |
| Age | ||||||||
| 8 m | 8.1 | 1.2 | 7.9 | 1.5 | 7.9 | 1.1 | 8.7 | 1.3 |
| 14 m | 14.4 | 1.3 | 14.1 | 1.4 | 14.3 | 1.2 | 15.1 | 1.4 |
| 24 m | 25.0 | 1.8 | 25.7 | 2.7 | 25.0 | 1.8 | 25.0 | 1.5 |
| 36 m | 38.8 | 2.9 | 40.2 | 3.6 | 38.6 | 3.0 | 38.9 | 2.2 |
| VABS | ||||||||
| Comm 8 m | 96.1 | 15.9 | 108.2 | 14.7 | 99.2 | 12.6 | 77.0 | 14.2 |
| Comm 14 m | 96.7 | 13.3 | 91.1 | 15.9 | 98.0 | 13.1 | 93.4 | 11.8 |
| Comm 24 m | 103.7 | 13.0 | 88.7 | 20.1 | 104.7 | 11.3 | 106.6 | 11.2 |
| Comm 36 m | 101.1 | 14.1 | 86.8 | 19.8 | 102.2 | 12.9 | 102.9 | 12.6 |
| DL 8 m | 100.1 | 13.7 | 106.7 | 18.4 | 101.3 | 12.3 | 91.9 | 13.8 |
| DL 14 m | 95.2 | 13.1 | 90.6 | 17.8 | 96.5 | 13.0 | 91.7 | 10.0 |
| DL 24 m | 105.7 | 12.9 | 94.4 | 20.0 | 106.7 | 11.9 | 106.7 | 10.1 |
| DL 36 m | 103.2 | 13.0 | 87.9 | 20.9 | 104.1 | 11.5 | 106.2 | 9.3 |
| Mot 8 m | 89.8 | 16.3 | 98.4 | 24.2 | 91.8 | 14.5 | 76.9 | 12.7 |
| Mot 14 m | 100.3 | 12.8 | 99.1 | 14.9 | 101.9 | 12.5 | 94.3 | 11.4 |
| Mot 24 m | 100.1 | 10.9 | 90.2 | 12.0 | 101.2 | 10.4 | 100.4 | 10.1 |
| Mot 36 m | 93.8 | 12.4 | 84.6 | 14.7 | 94.7 | 11.9 | 94.1 | 11.7 |
| Soc 8 m | 100.1 | 12.8 | 109.6 | 19.7 | 101.4 | 10.6 | 90.0 | 11.7 |
| Soc 14 m | 97.7 | 11.7 | 97.5 | 13.8 | 98.7 | 11.8 | 93.6 | 9.7 |
| Soc 24 m | 101.0 | 11.6 | 89.1 | 18.0 | 101.5 | 10.6 | 104.1 | 8.7 |
| Soc 36 m | 97.8 | 12.9 | 85.6 | 17.9 | 98.3 | 12.1 | 101.2 | 10.5 |
| MSEL | ||||||||
| ELC 8 m | 104.2 | 15.0 | 106.2 | 18.2 | 104.9 | 14.7 | 100.4 | 14.6 |
| ELC 14 m | 98.5 | 16.0 | 86.2 | 19.3 | 100.6 | 15.7 | 95.6 | 12.6 |
| ELC 24 m | 104.7 | 19.9 | 81.9 | 25.8 | 106.8 | 18.0 | 105.7 | 19.1 |
| ELC 36 m | 107.7 | 22.7 | 89.6 | 26.7 | 108.6 | 22.7 | 111.9 | 17.4 |
| ADOS at 36 m1 | ||||||||
| CSS-Tot | 2.95 | 2.40 | 3.84 | 3.00 | 2.94 | 2.43 | 2.60 | 1.90 |
| CSS-SA | 3.40 | 2.51 | 4.00 | 2.89 | 3.43 | 2.55 | 3.02 | 2.14 |
| CSS-RRB | 4.29 | 2.61 | 5.42 | 2.73 | 4.14 | 2.58 | 4.42 | 2.62 |
| ADI-R at 36 m2 | ||||||||
| ADI-Comm3 | 3.25 | 4.17 | 7.00 | 5.75 | 2.96 | 3.85 | 2.67 | 3.81 |
| ADI-Soc3 | 3.08 | 4.31 | 7.55 | 7.76 | 2.66 | 3.68 | 2.67 | 3.35 |
| ADI-RBI4 | 1.15 | 1.98 | 2.40 | 2.58 | 1.12 | 1.93 | 0.70 | 1.63 |
| SCQ at 36 m2 | ||||||||
| SCQ-Tot3 | 5.32 | 6.11 | 11.1 | 8.83 | 5.02 | 5.64 | 3.91 | 5.03 |
| Clinical outcome at 36 m5 | n (%) | n (%) | n6 (%) | n (%) | ||||
| LR | 74 (31) | 4 (20) | 56 (32) | 14 (32) | ||||
| HR-Typ | 87 (36) | 6 (30) | 63 (36) | 18 (42) | ||||
| HR-Atyp | 44 (18) | 2 (10) | 34 (19) | 8 (19) | ||||
| HR-ASD | 34 (14) | 8 (40) | 23 (13) | 3 (7) | ||||
| Gender | ||||||||
| Female | 122 (51) | 7 (35) | 92 (52) | 23 (53) | ||||
| Male | 118 (49) | 13 (65) | 85 (48) | 20 (47) | ||||
This table shows the descriptive statistics for the entire sample and for the different trajectory classes of adaptive behaviour
Tot entire sample, C1–C3 classes in trajectories of adaptive behaviour7, VABS Vineland Adaptive Behavior Scales, Comm communication score, DL daily living score, Mot motor score, Soc socialisation score, MSEL Mullen Scales of Early Learning, ELC early learning composite score, ADOS Autism Diagnostic Observation Schedule, CSS Calibrated Severity Score, ADI-R Autism Diagnostic Interview-Revised, ADI-Comm Communication domain score (ADI-R), ADI-Soc Social domain score (ADI-R), ADI-RBI Restricted Behaviors and Interests domain score (ADI-R), SCQ Social Communication Questionnaire, SCQ-Tot total score (SCQ), LR low-risk controls, HR high-risk siblings, HR-Typ typically developing siblings, HR-Atyp atypically developing siblings (no ASD), HR-ASD siblings with ASD
1Data were available for a subsample of n = 235 infants
2Data were available for a subsample of n = 239 infants
3Significant difference per class with p < 0.001
4Significant difference per class with p < 0.05
5Clinical outcome vs class membership: χ2 [6] = 13.39, p = 0.037
6One infant in this class did not receive a clinical outcome evaluation at 36 months
7C1, decreasing adaptive behaviour; C2, average/stable adaptive behaviour; C3, recovering adaptive behaviour