Table 9.
Dementia risk by each level of the risk score in the validation cohort.
| Sum score |
Number at riska | Dementia casesb | Mean time to incident dementia |
Observed ten year dementia riskc |
|---|---|---|---|---|
| N (%) | N (%) | Mean in y ±SD | (95% CI) | |
| −1 | 230(9·5%) | 4 (1·7%) | 9·5 ±0·0 | 3% (1 -7) |
| 0 | 85 (3·5%) | 4 (4.7%) | 7·4 ±0·1 | 7% (3 -18) |
| 1 | 90 (3·7%) | 3 (3·3%) | 7·2 ±0·1 | 4% (1-12) |
| 2 | 268 (11·1%) | 8 (3·0%) | 9·4 ±0·1 | 4% (2-8) |
| 3 | 125 (5·2%) | 9 (7.2%) | 7·8 ±0·1 | 9% (5-16) |
| 4 | 294 (12·2%) | 25 (8.5%) | 9·1 ±0·1 | 11% (8-16) |
| 5 | 215 (8·9%) | 28 (13.0%) | 8·8 ±0·1 | 17% (12-24) |
| 6 | 289 (12·0%) | 50 (17.3%) | 8·9 ±0·2 | 26% (20-33) |
| 7 | 317 (13·1%) | 53 (16.7%) | 8·7 ±0·2 | 22% (17-29) |
| 8 | 181 (7·5%) | 42 (23.2%) | 8·2 ±0·2 | 36% (28-46) |
| 9 | 139 (5·8%) | 43 (30.9%) | 7·3 ±0·3 | 50% (29-62) |
| 10 | 100 (4·1%) | 34 (34.0%) | 6·4 ±0·4 | 64% (47-82) |
| 11 | 27 (1·1%) | 11 (40.7%) | 6·1±0·7 | 61% (37-86) |
| 12-19 | 21 (0·69%) | 9 (42·9%) | 3·5 ±0·5 | 58% (32-86) |
a
Number at risk: number of subjects within each sum score group, with percentage of the total cohort in brackets.
b
Number of dementia cases in this sum score group: the percentage is the proportion of persons with incident dementia in that particular sum score group.
c
based on Kaplan-Meier estimates.