Table 2.
Sleep duration and mortality: overall and age stratified analysis
| Sleep duration, hours/day | Crude | Multivariable adjusteda | ||||||
|---|---|---|---|---|---|---|---|---|
| No. of deaths | Person-years | HR | 95% CI | No. of deaths | Person-years | HR | 95% CI | |
| ≤5 h | 486 | 40,469 | 1.13 | 1.01, 1.25 | 337 | 31,571 | 1.12 | 0.99, 1.27 |
| 6 h | 761 | 116,938 | 1.00 | 0.92, 1.10 | 564 | 95,917 | 0.98 | 0.88, 1.09 |
| 7 h | 1255 | 215,222 | 1.00 | Referent | 984 | 181,815 | 1.00 | Referent |
| ≥8 h | 1046 | 124,483 | 1.15 | 1.05, 1.24 | 805 | 103,352 | 1.10 | 1.00, 1.20 |
| Age <65 | ||||||||
| ≤5 h | 127 | 28,119 | 1.45 | 1.19, 1.77 | 98 | 22,409 | 1.37 | 1.09, 1.71 |
| 6 h | 262 | 96,875 | 0.99 | 0.85, 1.15 | 211 | 80,596 | 0.92 | 0.77, 1.08 |
| 7 h | 482 | 181,293 | 1.00 | Referent | 396 | 154,272 | 1.00 | Referent |
| ≥8 h | 340 | 95,764 | 1.32 | 1.15, 1.52 | 270 | 80,051 | 1.27 | 1.08, 1.48 |
| Age ≥65 | ||||||||
| ≤5 h | 359 | 12,350 | 1.02 | 0.90, 1.16 | 239 | 9162 | 1.05 | 0.90, 1.22 |
| 6 h | 499 | 20,063 | 1.01 | 0.90, 1.13 | 353 | 15,321 | 1.03 | 0.90, 1.17 |
| 7 h | 773 | 33,930 | 1.00 | Referent | 588 | 27,542 | 1.00 | Referent |
| ≥8 h | 706 | 28,719 | 1.06 | 0.96, 1.18 | 535 | 23,301 | 1.01 | 0.90, 1.14 |
aHazard ratios were adjusted for age, sex, BMI, smoking status, alcohol consumption, educational level, physical activity and major diseases. Attained age was used as time scale