Table 1. Summary demographics and cognitive status scores for cross-sectional and longitudinal analyses.
Mean (SD) unless otherwise stated.
| Cross-sectional dataset | Longitudinal dataset | ||
|---|---|---|---|
| N | 7154 | 3960 | |
| N Alzheimer Disease Centers | 33 | 31 | |
| Age at first presentation, years | 75.5 (9.6) | 75.1 (9.5) | |
| Age at onset, years | 70.7 (9.7) | 70.2 (9.6) | |
| Symptom length, years | 4.8 (3.4) | 4.8 (3.3) | |
| Gender % women | 55.9 | 53.1 | |
| N Probable AD (%) | 5953 (83.2) | 3353 (84.7) | |
| Education, years | 13.9 (3.8) | 14.2 (3.7) | |
| MMSE at first presentation, /30 | 19.4 (6.8) | 20.5 (6.1) | |
| MMSE at second presentation, /30 ^ | N/A | 18.4 (7.0) | |
| CDR SOB at first presentation, /18 | 6.7 (4.1) | 6.1 (3.7) | |
| CDR SOB at second presentation, /18 | N/A | 7.8 (4.4) | |
| Interval between visits 1 and 2 for MMSE, days ^ | N/A | 425.0 (137.9) | |
| Annualised change in MMSE (points/year) ^ | N/A | −2.1 (3.6) | |
| Interval between visits 1 and 2 for CDR sum of boxes, days | N/A | 427.2 (141.7) | |
| Annualised change in CDR sum of boxes (points/year) | N/A | 1.5 (2.3) | |
| First predominant cognitive symptom % # | Memory | 89.2 | 90.1 |
| Judgment and problem solving | 3.6 | 3.1 | |
| Language | 4.0 | 3.7 | |
| Visuospatial function | 2.2 | 2.3 | |
| Attention / concentration | 0.6 | 0.5 | |
| “Other” | 0.4 | 0.4 | |
| Fluctuating cognition | 0.1 | 0.0 | |
| No symptom | 0.0 | 0.0 | |
| APOE ε4 status %0, 1, 2 alleles ¥ | 42.2, 45.4, 12.4 | 41.6, 45.7, 12.7 | |
^
data available in 3816;
#
data available in 7134 for cross-sectional analysis and 3955 for longitudinal;
¥
data available in 4885 for cross-sectional analysis and 3052 for longitudinal; N/A - not applicable