Table 1.
Demographic characteristics per study group.
| Healthy control | Preclinical AD | Prodromal AD | p value | |
|---|---|---|---|---|
| N | 57 | 27 | 37 | |
| Age | 68 (7) | 71 (5) | 70 (8) | 0.12 |
| Years of education | 15 (3) | 15 (3) | 15 (5) | 0.69 |
| Male, n (%) | 26 (46%) | 10 (37%) | 24 (65%) | 0.06 |
| Site, n (%) | ||||
| - Amsterdam | 20 (35%) | 12 (44%) | 10 27%) | |
| - London | 5 (9%) | 0 (0%) | 3 (8%) | |
| - Oxford | 5 (9%) | 0 (0%) | 1 (0%) | |
| - Stockholm | 0 (0%) | 2 (7%) | 6 (16%) | |
| - Thessaloniki | 5 (9%) | 0 (0%) | 3 (8%) | |
| - Ljubljana | 2 (4%) | 1 (4%) | 1 (0%) | |
| - Lisbon | 5 (9%) | 0 (0%) | 2 (5%) | |
| - Brescia | 4 (7%) | 0 (0%) | 3 (5%) | |
| - Geneva | 2 (4%) | 5 (19%) | 4 (8%) | |
| - Mannheim | 0 (0%) | 0 (0%) | 3 (8%) | |
| - Barcelona | 4 (7%) | 0 (0%) | 2 (3%) | |
| - Stavanger | 5 (9%) | 7 (26%) | 4 (11%) | |
| MMSE | 29 (1) | 29 (1) | 27 (2) | <0.001 |
| Aβ available, n (%) | 43 (75%) | 27 (100%) | 37 (100%) | |
| DSST score | 49 (11) | 46 (10) | 35 (13) | <0.001 |
| Verbal fluency score | 64 (16) | 66 (16) | 53 (19) | 0.003 |
| Word list recall score, % | 70 (20) | 74 (20) | 35 (29) | <0.001 |
| Boston naming test score, % | 94 (6) | 92 (7) | 87 (13 | 0.001 |
| Rey drawing score | 34 (2) | 34 (2) | 31 (7) | <0.001 |
| Rey recall score | 21 (7) | 19 (6) | 13 (8) | <0.001 |
| Cognitive score | −0.05 (0.67) | −0.16 (0.58) | −1.50 (1.38) | <0.001 |
| A-IADL score | 68.4 (2.6) | 66.8 (3.0) | 60.8 (6.5) | <0.001 |
| Digital score | 62.2 (21.3) | 50.7 (21.6) | 33.2 (20.0) | <0.001 |
Numbers show mean (SD), unless specified otherwise. The different sites used their own local language for the tests. P values are from ANOVAs or χ2 tests where appropriate, uncorrected for any covariates.
Aβ amyloid beta, AD Alzheimer’s disease, A-IADL Amsterdam instrumental activities of daily living, DSST Digit Symbol Substitution Test, MMSE Mini-Mental State Examination.