Table 2.
Baseline stratification, 3-yr cumulative rates of progression to probable AD dementia, and Weibull parameters for time to progression to probable AD dementia.
| Risk Stratum | Definition | PPG Cohort | NACC-UDS Cohort1 | |||||
|---|---|---|---|---|---|---|---|---|
|
| ||||||||
| CDR sum of boxes | Memory Z-score | N (%) | 3-yr cumulative event rate (%, 95% CI) | N (%) | 3-yr cumulative event rate (%, 95% CI) | Weibull Shape (a) | Weibull Scale (b) | |
| All non-demented | 358 (100%) | 11.3 (8.4 to 15.2) | 5871 (100%) | 9.6 (8.7 to 10.5) | 1.62 (1.51 to 1.73) | 12.9 (11.6 to 14.3) | ||
| Low-risk | ≤ 1 | > −0.43 | 160 (45%) | 1.3 (0.3 to 5.1) | 2861 (49%) | 1.4 (1.0 to 2.0) | 1.86 (1.74 to 1.98) | 27.2 (22.5 to 32.9) |
| Mid-risk | ≤ 1 or > 1 |
≤ −0.43 > −2.00 |
182 (51%) | 15.0 (10.4 to 21.4) | 2705 (46%) | 13.4 (11.9 to 15.1) | 8.58 (7.90 to 9.32) | |
| High-risk | > 1 | ≤ −2.00 | 16 (4%) | 72.2 (49.0 to 91.2) | 305 (5%) | 61.7 (54.8 to 68.6) | 3.09 (2.84 to 3.37) | |
| CDR 0.5 only | 241 (100%) | 16.8 (12.5 to 22.3) | 2139 (100%) | 24.2 (22.0 to 26.5) | 1.68 (1.56 to 1.81) | 6.65 (6.16 to 7.19) | ||
| Low-risk | ≤ 1 | > −0.38 | 77 (32%) | 2.7 (0.7 to 10.4) | 473 (22%) | 5.3 (3.3 to 8.4) | 1.83 (1.70 to 1.96) | 15.9 (12.4 to 20.3) |
| Mid-risk | ≤ 1 or > 1 |
≤ −0.38 > −2.00 |
148 (61%) | 18.4 (12.8 to 26.0) | 1361 (64%) | 22.9 (20.2 to 25.9) | 6.32 (5.83 to 6.85) | |
| High-risk | > 1 | ≤ −2.00 | 16 (7%) | 72.2 (49.0 to 91.2) | 305 (14%) | 61.7 (54.8 to 68.6) | 3.10 (2.84 to 3.39) | |
1
Only participants with non-missing memory Z-scores are included. This excludes 248 CDR 0 and 124 CDR 0.5 NACC-UDS participants.