Table 3.
Adjusted hazard ratios for sleep duration at follow-up II (2006–2010) and mortality, the Singapore Chinese Health Study
| Cause of death | Sleep duration at follow-up II | ||||
|---|---|---|---|---|---|
| ≤5 hr | 6 hr | 7 hr | 8 hr | ≥9 hr | |
| All-cause | |||||
| No. of deaths | 582 | 681 | 994 | 1256 | 2097 |
| Model 1† | 1.14 (1.03–1.26) | 1.04 (0.94–1.15) | 1.00 (referent) | 1.09 (1.00–1.19) | 1.40 (1.30–1.51) |
| Model 2‡ | 1.11 (1.01–1.23) | 1.04 (0.94–1.14) | 1.00 (referent) | 1.08 (0.99–1.17) | 1.35 (1.25–1.46) |
| Cardiovascular | |||||
| No. of deaths | 191 | 191 | 282 | 360 | 666 |
| Model 1† | 1.33 (1.11–1.60) | 1.03 (0.85–1.23) | 1.00 (referent) | 1.11 (0.95–1.29) | 1.57 (1.36–1.81) |
| Model 2‡ | 1.27 (1.05–1.52) | 1.03 (0.86–1.24) | 1.00 (referent) | 1.08 (0.93–1.27) | 1.50 (1.30–1.73) |
| Ischemic heart disease | |||||
| No. of deaths | 103 | 102 | 169 | 210 | 343 |
| Model 1† | 1.22 (0.95–1.56) | 0.91 (0.71–1.16) | 1.00 (referent) | 1.09 (0.89–1.33) | 1.38 (1.14–1.66) |
| Model 2‡ | 1.15 (0.90–1.48) | 0.92 (0.72–1.18) | 1.00 (referent) | 1.06 (0.87–1.30) | 1.32 (1.09–1.59) |
| Stroke | |||||
| No. of deaths | 39 | 51 | 67 | 91 | 198 |
| Model 1† | 1.12 (0.75–1.66) | 1.16 (0.81–1.67) | 1.00 (referent) | 1.16 (0.85–1.60) | 1.92 (1.45–2.55) |
| Model 2‡ | 1.06 (0.71–1.57) | 1.16 (0.80–1.66) | 1.00 (referent) | 1.13 (0.82–1.55) | 1.77 (1.33–2.35) |
| Cancer | |||||
| No. of deaths | 191 | 270 | 415 | 477 | 636 |
| Model 1† | 0.94 (0.79–1.11) | 0.97 (0.83–1.13) | 1.00 (referent) | 1.03 (0.90–1.18) | 1.16 (1.02–1.32) |
| Model 2‡ | 0.93 (0.78–1.10) | 0.97 (0.83–1.12) | 1.00 (referent) | 1.03 (0.90–1.17) | 1.13 (1.00–1.29) |
†Model 1 adjusted for age (years), year of recruitment (1993–1995 and 1996–1998), gender, dialect group (Hokkien and Cantonese), physical activity (<0.5, 0.5–4, and ≥4 hr/week), level of education (no formal education, primary school, secondary school, or higher), smoking status (never, former, and current), alcohol intake (none, weekly, and daily), and body mass index (<20, 20–<24, 24–<28, and ≥28 kg/m2).
‡Model 2 further adjusted for history of hypertension, ischaemic heart disease, stroke, diabetes, and cancer.