Table 3.
Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between sleep duration and all-cause mortality, stratified by demographic and socioeconomic factors
| HR (95% CI) | |||||||
|---|---|---|---|---|---|---|---|
| Death/Person-year | Weighteda Death/Person-year | Sleep duration, h/day | P-interaction | ||||
| ≤4 | 5–6 | 7–8 | ≥9 | ||||
| Age | |||||||
| < 65 years | 285/148,367 | 1,773,342/1,085,263,610 | 1.46 (0.75–2.83) | 0.87 (0.64–1.20) | 1.00 (Referent) | 1.58 (1.00–2.48) | 0.56 |
| ≥ 65 years | 743/33,073 | 2,930,659/124,393,702 | 0.86 (0.64–1.15) | 0.87 (0.71–1.07) | 1.00 (Referent) | 1.27 (0.97–1.67) | |
| Sex | |||||||
| Male | 620/77,615 | 2,913,160/611,437,975 | 1.06 (0.69–1.64) | 0.99 (0.79–1.24) | 1.00 (Referent) | 1.35 (0.96–1.89) | 0.69 |
| Female | 408/103,824 | 1,790,841/598,219,336 | 0.97 (0.66–1.45) | 0.78 (0.59–1.03) | 1.00 (Referent) | 1.43 (0.99–2.06) | |
| Education | |||||||
| Less than High school | 782/48,304 | 3,343,865/317,448,992 | 0.94 (0.71–1.26) | 0.92 (0.74–1.14) | 1.00 (Referent) | 1.39 (1.06–1.81) | 0.89 |
| High school | 128/35,469 | 963,827/489,412,883 | 1.20 (0.45–3.23) | 0.83 (0.55–1.28) | 1.00 (Referent) | 1.23 (0.63–2.39) | |
| College or higher | 118/97,668 | 396,310/ 402,795,436 | 2.02 (0.61–6.69) | 0.87 (0.50–1.54) | 1.00 (Referent) | 1.75 (0.62–4.95) | |
| Occupation | |||||||
| Non-physical labor | 47/38,660 | 269,418/293,918,617 | 2.36 (0.42–3.36) | 0.69 (0.37–1.31) | 1.00 (Referent) | 0.43 (0.04–4.42) | 0.39 |
| Physical labor | 357/73,971 | 1,662,546/494,418,683 | 1.25 (0.71–2.20) | 0.92 (0.67–1.26) | 1.00 (Referent) | 1.16 (0.73–1.84) | |
| Unemployed | 624/68,809 | 2,772,037/421,320,011 | 0.92 (0.67–1.27) | 0.89 (0.72–1.12) | 1.00 (Referent) | 1.52 (1.13–2.04) | |
aWeighted deaths and person-years were estimated by accounting for complex sampling design (strata, cluster, sampling weight)
All models were accounted for complex sampling design (sampling weight, cluster, strata) and included age (in month, as time metameter), sex (male, female), marital status (married, divorced/separated/widowed, never married), education (less than high school, high school, college or higher), occupation (non-physical labor, physical labor, unemployed), household income (quartiles), region (rural, urban), smoking status (never, former, current), physical activity (< 10, ≥10 MET-h/wk), body mass index (< 18.5, 18.5–22.9, 23.0–24.9, ≥25.0 kg/m2), alcohol drinking (glass/day), and self-rated health (very good, good, fair, poor)
P-interaction was estimated using Wald test for product terms
Abbreviations: CI confidence interval, HR hazard ratio, MV multivariable