Table 1.
Mortality by Number of Hours Sleep at Phase 1 and Phase 3
| Hours of sleep | ≤5 hours | 6 hours | 7 hours | 8 hours | ≥9 hours |
|---|---|---|---|---|---|
| Phase 1 (No. participants=9,781, Total deaths=566) |
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| Number of participants (deaths: all causes) | 587 (56) | 2642 (160) | 4884 (256) | 1579 (87) | 89 (7) |
| Hazard ratio (95% CI) - Age adjusted | 1.61 (1.20–2.15) | 1.11 (0.91–1.35) | reference | 1.08 (0.85–1.38) | 1.77 (0.84–3.76) |
| - Fully adjusted # | 1.24 (0.92–1.67) | 1.00 (0.82–1.22) | reference | 1.07 (0.84–1.36) | 1.54 (0.72–3.28) |
| Number of participants (CVD deaths) | 585 (19) | 2642 (47) | 4881 (69) | 1579 (31) | 89 (2) |
| Hazard ratio (95% CI) - Age adjusted | 2.11 (1.26–3.52) | 1.22 (0.84–1.76) | reference | 1.47 (0.96–2.25) | 2.18 (0.53 –8.92) |
| - Fully adjusted # | 1.17 (0.68–2.00) | 1.01 (0.69–1.48) | reference | 1.39 (0.91–2.14) | 1.53 (0.37–6.32) |
| Number of participants (non-CVD deaths) | 585 (35) | 2642 (113) | 4881 (184) | 1579 (56) | 89 (5) |
| Hazard ratio (95% CI) - Age adjusted | 1.38 (0.96–1.99) | 1.09 (0.86–1.37) | reference | 0.95 (0.71–1.29) | 1.66 (0.68–4.05) |
| - Fully adjusted # | 1.18 (0.81–1.71) | 1.02 (0.80–1.29) | reference | 0.96 (0.71–1.30) | 1.61 (0.66–3.94) |
| Phase 3 (No. participants=7,729, Total deaths=292) |
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| Number of participants (deaths: all causes) | 420 (29) | 1626 (61) | 3501 (112) | 1950 (74) | 232 (16) |
| Hazard ratio (95% CI) - Age adjusted | 2.07 (1.38–3.13) | 1.21 (0.89–1.66) | reference | 1.13 (0.85–1.52) | 2.00 (1.18–3.38) |
| - Fully adjusted # | 1.78 (1.17–2.71) | 1.13 (0.83–1.55) | reference | 1.11 (0.82–1.48) | 1.95 (1.15–3.31) |
| Number of participants (CVD deaths) | 419 (13) | 1626 (22) | 3499 (34) | 1949 (14) | 232 (6) |
| Hazard ratio (95% CI) - Age adjusted | 3.12 (1.64–5.94) | 1.48 (0.86–2.53) | reference | 0.69 (0.37–1.28) | 2.31 (0.97–5.51) |
| - Fully adjusted # | 2.25 (1.15–4.38) | 1.22 (0.70–2.10) | reference | 0.64 (0.34–1.20) | 2.23 (0.93–5.38) |
| Number of participants (non-CVD deaths) | 419 (15) | 1625 (38) | 3499 (76) | 1949 (59) | 232 (10) |
| Hazard ratio (95% CI) - Age adjusted | 1.57 (0.90–2.74) | 1.10 (0.75–1.63) | reference | 1.35 (0.95–1.89) | 1.88 (0.97–3.64) |
| - Fully adjusted # | 1.43 (0.81–2.52) | 1.07 (0.72–1.58) | reference | 1.34 (0.96–1.89) | 1.88 (0.97–3.66) |
#
Fully adjusted hazard ratios are adjusted for:- age, sex, marital status, employment grade, smoking status, physical activity, alcohol consumption, self-rated health, body mass index, systolic blood pressure, cholesterol, physical illness, modified GHQ score, prevalent CHD