Table 3.
Parameters of development in social interactions by intellectual disability and Gross Motor Function Classification System (GMFCS) level
| GMFCS level | n | Limit | (95% CI) | 50% range around limit | Age90 (y:mo) | (95% CI) | Residual SDs | Offseta | |
|---|---|---|---|---|---|---|---|---|---|
| Interrelationships | |||||||||
| No intellectual disability | I | 194 | 46.0 | (45.4–46.6) | 43.9–48.0 | 6:4 | (5:11–6:9) | 2.4 | 0.0 |
| II | 42 | 45.8 | (44.4–47.2) | 44.0–47.6 | 7:6 | (6:9–8:4) | 2.8 | 0.0 | |
| III | 36 | 44.6 | (43.0–46.2) | 42.7–46.6 | 6:3 | (5:7–7:1) | 2.9 | 0.0 | |
| IV | 28 | 46.1 | (44.6–47.5) | 44.1–48.0 | 6:10 | (6:1–7:9) | 2.1 | 0.0 | |
| Intellectual disability | I–IV | 38 | 38.7 | (36.0–41.4) | 35.8–41.7 | 7:4 | (5:4–10:3) | 4.1 | 0.0 |
| V | 29 | 23.9 | (18.7–29.0) | 15.7–32.0 | 6:2 | (2:0–19:2) | 4.7 | 0.0 | |
| Play and leisure | |||||||||
| No intellectual disability | I | 194 | 38.8 | (38.1–39.5) | 37.1–40.0 | 14:6 | (13:10–15:2) | 2.4 | 0.0 |
| II | 42 | 40.3 | (38.7–41.8) | 39.5–40.0 | 16:7 | (15:2–18:3) | 2.8 | 0.0 | |
| III | 36 | 37.7 | (35.6–39.9) | 35.8–39.7 | 13:8 | (12:1–15:4) | 2.4 | 0.0 | |
| IV | 28 | 37.2 | (35.1–39.4) | 35.2–39.3 | 14:0 | (11:11–16:5) | 3.1 | 0.0 | |
| Intellectual disability | I–IV | 38 | 26.5 | (23.2–29.7) | 23.2–29.7 | 10:4 | (7:2–14:10) | 3.7 | 0.0 |
| V | 29 | 14.7 | (10.7–18.7) | 8.4–21.1 | 5:8 | (1:0–32:11) | 4.0 | 0.0 | |
| Coping | |||||||||
| No intellectual disability | I | 192 | 35.6 | (34.5–36.7) | 32.7–38.4 | 14:8 | (13:9–15:9) | 3.5 | 2.1 |
| II | 42 | 36.6 | (34.0–39.2) | 34.3–38.9 | 16:2 | (14:3–18:6) | 3.2 | 2.1 | |
| III | 36 | 34.4 | (30.5–38.3) | 30.9–37.9 | 15:7 | (13:0–18:10) | 3.6 | 2.1 | |
| IV | 28 | 35.1 | (32.6–37.5) | 32.7–37.5 | 14:0 | (11:10–16:8) | 3.6 | 2.1 | |
| Intellectual disability | I–IV | 38 | 18.8 | (14.5–23.0) | 13.6–23.9 | 10:2 | (6:5–17:2) | 5.3 | 2.1 |
| V | 29 | 8.0 | (4.0–12.1) | 0.9–15.1 | 7:1 | (5:2–46:9) | 4.3 | 5.1b | |
aOffset refers to the start age of development in years. bWith respect to coping, the model for individuals with intellectual disability and GMFCS level V did not fit when the offset was determined based on all observations. Therefore, the offset for this subgroup was based on the observations of the subgroup (5y 1mo).