TABLE 2.
Demographic and neuropsychological characteristics of the study samples at baseline according to cognitive cluster assignment.
| CUN dataset (n = 630) | ADNI dataset (n = 734) | |||||
|---|---|---|---|---|---|---|
| Characteristics | Cluster 1 (n = 332) | Cluster 2 (n = 298) | P | Cluster 1 (n = 400) | Cluster 2 (n = 334) | P |
| Age (years) | 65 (59, 70) | 69 (62, 75) | – | 70 (67, 76) | 71 (67, 76) | – |
| Sex | ||||||
| Male | 167 (50%) | 159 (53%) | 0.473 | 168 (42%) | 141 (42%) | 0.999 |
| Female | 165 (50%) | 139 (47%) | 232 (58%) | 193 (58%) | ||
| Education | ||||||
| 0–1 | 116 (35%) | 117 (39%) | – | 17 (16, 18) | 16 (14, 18) | – |
| 2–4 | 216 (65%) | 181 (61%) | ||||
| Memory complaints | ||||||
| Yes | 332 (100%) | 298 (100%) | – | 200 (50%) | 187 (56%) | 0.119 |
| No | 0 (0%) | 0 (0%) | 200 (50%) | 147 (44%) | ||
| GDS | ||||||
| 15 items | – | – | – | 0 (0, 1) | 1 (0, 1) | 0.004 |
| 30 items | 7 (4, 11) | 9 (5, 13) | <0.001 | – | – | – |
| MMSE | 29 (28, 30) | 28 (27, 29) | – | 30 (29, 30) | 29 (28, 30) | – |
| Delayed recall | 5 (4, 7) | 4 (3, 5) | – | 8 (7, 9) | 7 (5, 8) | – |
| Categorical fluency | 19 (16, 21) | 14 (11, 17) | – | 23 (20, 26) | 18 (15, 21) | – |
| Phonological fluency | 15 (12, 18) | 11 (9, 14) | – | – | – | – |
| Boston Naming Test | 54 (51, 56) | 50 (47, 53) | – | – | – | – |
| SCWT | 48 (44, 53) | 42 (38, 47) | – | – | – | – |
| Raven's matrices | 32 (28, 34) | 27 (24, 29) | – | – | – | – |
| TMT‐A (seconds) | 32 (28, 34) | 52 (40, 69) | – | 27 (23, 32) | 36 (30, 44) | – |
| TMT‐B (seconds) | 76 (59, 93) | 131 (99, 170) | – | 59 (49, 76) | 86 (71, 112) | – |
Note: Descriptive statistics are given as median (interquartile range) or frequency (percentage). Educational attainment is encoded as an ordered variable in the CUN dataset (0 = no formal education; 1 = pre‐college [primary education]; 2 = college or vocational training; 3 = bachelor degree/diploma; 4 = doctorate/master's degree), while in the ADNI dataset, it is represented in years. Delayed recall corresponds to the CERAD items in the CUN dataset and the ADAS‐Cog items in the ADNI dataset. P values correspond to Wilcoxon rank sum test or Pearson chi‐squared test. Note that it is not appropriate to apply hypothesis tests to compare the variables used for clustering, which explains the absence of their P values.
Abbreviations: ADAS‐Cog, Alzheimer's Disease Assessment Scale‐Cognitive Subscale; ADNI, Alzheimer's Disease Neuroimaging Initiative; CERAD, Consortium to Establish a Registry for Alzheimer's Disease; CUN, Clínica Universidad de Navarra; GDS, Geriatric Depression Scale; MMSE, Mini‐Mental State Examination; SCWT, Stroop Color and Word Test; TMT‐A, Trail Making Test Part A; TMT‐B, Trail Making Test Part B.