Table 2.
General linear mixed models of premorbid intellectual disability (ID) level on cognitive outcomes
| Estimate (Standard Error) or F value | |||||
| Block Design | mCRT | DSMSE | DLD Social | DLD Cognitive | |
| Site (random effect) | 3.227** | 5.297** | 1.245 | 3.286** | 3.671** |
| Age | –0.110 (0.093) | –0.044 (0.073) | –0.294 (0.106)* | 0.016 (0.049) | 0.060 (0.055) |
| Biological Sex | –0.933 (1.104) | 0.332 (0.863) | 1.385 (1.256) | 0.393 (0.584) | –0.579 (0.650) |
| Trisomy type (versus full), F value | 1.957 (0.143) | 1.647 (0.194) | 0.495 (0.610) | 0.202 (0.817) | 0.602 (0.548) |
| Mosaic | –1.317 (2.577) | –3.645 (2.196) | –1.470 (2.956) | 0.789 (1.372) | 1.293 (0.527) |
| Translocation | 4.275 (2.256) | 1.190 (1.734) | 2.169 (2.562) | –0.303 (1.202) | –0.898 (1.338) |
| APOE ɛ4 | –0.472 (1.146) | 0.197(0.994) | 0.057 (1.416) | –0.486 (0.662) | 0.064 (0.737) |
| Clinical Status (versus CS), F value | 32.949** | 75.578** | 47.770** | 53.556** | 104.733** |
| MCI-DS | –3.922 (1.698)* | –9.329 (1.329)** | – 5.733 (1.951)** | 2.060 (0.906)* | 4.021 (1.008)** |
| Dementia | –15.270 (1.881)** | –18.560 (1.617)** | –20.869 (2.136)** | 10.011 (0.969)** | 15.608 (1.078)** |
| Premorbid ID (versus mild), F value | 2.603 | 0.166 | 5.188** | 0.491 | 0.308 |
| Moderate | –7.609 (5.256) | 2.387 (4.165) | –13.0334 (5.990)* | 0.848 (2.797) | 0.543 (3.114) |
| Severe/Profound | –15.801 (7.490)* | 0.0695 (5.958) | –24.734 (8.506)** | 3.954 (3.988) | 3.478 (4.439) |
| Age×Premorbid ID, F value | 0.054 | 1.672 | 0.194 | 0.003 | 1.678 |
| Age×Moderate | 0.029 (0.114) | –0.113 (0.091) | 0.072 (0.130) | 0.004 (0.060) | 0.070 (0.067) |
| Age×Severe/Profound | –0.019 (0.166) | –0.220 (0.137) | –0.020 (0.189) | –0.002 (0.088) | 0.171 (0.098) |
ID, intellectual disability; CS, cognitively stable; MCI-DS, mild cognitive impairment-Down syndrome; AD, Alzheimer’s disease; DSMSE, Down Syndrome Mental Status Examination; DLD, The Dementia Questionnaire for People with Learning Disabilities. Age2 was not significantly related to Block Design (–0.045 [0.657]), mCRT (–0.012[(0.09]), DSMSE (0.003 [0.002]), DLD Social (0.033 [0.029]) or DLD Cognitive (0.002 [0.002]). Age2×Premorbid ID was not significantly related to Block Design (F = 0.087, p = 0.765), mCRT (F = 01.654, p = 0.322), DSMSE (0.176, p = 0.829), DLD Social (F = 0.006, p = 0.711). or DLD Cognitive (F = 1.50, p = 0.231]). *p < 0.05; **p < 0.01.