Table 3. Mean amnestic and non-amnestic T scores by sleep quantity categories for the younger and older age groups.
| AMNESTIC | YOUNGER GROUP (50–64 yrs) | OLDER GROUP (65+yrs) | |||
| Model | Sleep Quantity | Mean T Score(SE) | p and R2 values | Mean T Score(SE) | p and R2 values |
| 0 | <6 hr | 48.4 (0.2) | 49.4 (0.3) | ||
| (unadjusted) | 6–8 hr | 50.4 (0.1) | 50.4 (0.1) | ||
| >8 hr | 48.6 (0.4) | p<0.001; R2 = 0.014 | 47.5 (0.4) | p<0.001; R2 = 0.016 | |
| 1 | <6 hr | 48.3 (0.2) | 49.4 (0.3) | ||
| (age+sex, sleep*age) | 6–8 hr | 50.3 (0.1) | 50.4 (0.1) | ||
| >8 hr | 48.6 (0.4) | p<0.001; R2 = 0.028 | 48.1 (0.3) | p<0.001; R2 = 0.125 | |
| 2 | <6 hr | 48.5 (0.2) | 50.0 (0.3) | ||
| (Model 1+ education, | 6–8 hr | 49.8 (0.1) | 50.5 (0.1) | ||
| employment grade) | >8 hr | 48.7 (0.4) | p<0.001; R2 = 0.123 | 48.4 (0.3) | p<0.001; R2 = 0.189 |
| 3 | <6 hr | 47.8 (0.3) | 49.7 (0.3) | ||
| (Model 2+ depression, physical, | 6–8 hr | 48.5 (0.2) | 49.7 (0.2) | ||
| activity, smoking, general health) | >8 hr | 47.6 (0.4) | p = 0.003; R2 = 0.152 | 47.7 (0.4) | p<0.001; R2 = 0.213 |
| NON-AMNESTIC | |||||
| 0 | <6 hr | 48.8 (0.2) | 49.2 (0.2) | ||
| (unadjusted) | 6–8 hr | 50.3 (0.1) | 50.4 (0.1) | ||
| >8 hr | 48.4 (0.4) | p<0.001; R2 = 0.014 | 48.3 (0.3) | p<0.001; R2 = 0.013 | |
| 1 | <6 hr | 48.8 (0.2) | 49.4 (0.2) | ||
| (age+sex, sleep*age) | 6–8 hr | 50.3 (0.1) | 50.3 (0.1) | ||
| >8 hr | 48.5 (0.4) | p<0.001; R2 = 0.023 | 48.7 (0.3) | p<0.001; R2 = 0.110 | |
| 2 | <6 hr | 49.0 (0.2) | 50.1 (0.2) | ||
| (Model 1+ education, | 6–8 hr | 49.7 (0.1) | 50.5 (0.1) | ||
| employment grade) | >8 hr | 48.5 (0.3) | p<0.001; R2 = 0.182 | 49.1 (0.3) | p<0.001; R2 = 0.225 |
| 3 | <6 hr | 48.7 (0.2) | 49.8 (0.2) | ||
| (Model 2+ depression, physical, | 6–8 hr | 48.9 (0.2) | 49.7 (0.2) | ||
| activity, smoking, general health) | >8 hr | 47.9 (0.4) | p = 0.010; R2 = 0.206 | 48.4 (0.3) | p<0.001; R2 = 0.256 |