Table 1 Baseline and follow-up sample characteristics
Baseline characteristics | Total sample | Amyloid normal | Amyloid abnormal |
|---|---|---|---|
N Manchester cohort, n (%) Amsterdam cohort, n (%) | 276 77 (27.9) 199 (72.1) (97 complete twin pairs) | 218 49 (22.5) 169 (77.5) (76 complete twin pairs) | 52 27 (51.9) 25 (48.1) (6 complete twin pairs) |
Age, mean (SD) Age range | 74.66 (9.65) 60.3–94.7 | 73.28 (9.47) 60.3–94.3 | 80.14 (7.66) * 62.9–94.7 |
Female, n (%) | 174 (63.0) | 134 (61.5) | 37 (71.2) |
Years of education, mean (SD) | 11.47 (2.74) | 11.56 (2.67) | 11.24 (3.09) |
Amyloid-β PET$, n (%) | 270 (96.4) | 218 (80.7) | 52 (19.3) |
APOE genotype, n (%) | |||
e2e2 | 2 (0.7) | 2 (0.9) | 0 (0) |
e2e3 | 32 (11.6) | 28 (12.8) | 4 (7.7) |
e2e4 | 9 (3.3) | 7 (3.2) | 2 (3.8) |
e3e3 | 157 (56.9) | 129 (59.2) | 23 (44.2) |
e3e4 | 68 (24.6) | 49 (22.5) | 18 (34.6) |
e4e4 | 7 (2.5) | 2 (0.9) | 5 (9.6) |
APOE ɛ4# carrier, n (%) | 84 (30.5) | 58 (26.7) | 25 (48.1) |
Polygenic Risk Score for Alzheimer’s disease^ (z score), mean (SD) | 0.00 (1.00) | -0.06 (1.00) | 0.24 (0.99) |
Neuropsychological testing, n (%) | 274 (97.9) | 216 (99) | 52 (100) |
MMSE, mean (SD) | 28.9 (1.24) | 29.0 (1.10) | 28.5 (1.48) ~ |
Composite memory (z score), mean (SD) | -0.02 (0.71) | 0.04 (0.69) | -0.23 (0.71) * |
Composite attention (z score), mean (SD) | -0.25 (0.84) | -0.22 (0.85) | -0.34 (0.77) |
Composite executive function (z score), mean (SD) | -0.44 (0.62) | -0.38 (0.59) | -0.67 (0.65) * |
Composite language (z score), mean (SD) | -0.25 (0.81) | -0.17 (0.76) | -0.58 (0.95) * |
Follow-up characteristics | |||
Follow-up time, mean (SD), y | 2.04 (0.41) | 2.01 (0.39) | 2.16 (0.51) |
Still in the study at follow-up, n (%) | 226 (81.9) | 184 (84.4) | 41 (78.8) |
Lost to follow-up | 50 (18.1) | 34 (15.6) | 11 (21.2) |