Table 1. Pooled measures on the relation of nighttime sleep duration and risk of all-cause mortality.
| RR (95% CI) by hours of nighttime sleep per day |
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Na | Deaths | 4 hours | 5 hours | 6 hours | 7 hours | 8 hours | 9 hours | 10 hours | 11 hours | |
| Overall | 36 | 146,830 | 1.07 (1.03–1.13) | 1.04 (1.01–1.07) | 1.01 (1.00–1.02) | 1.00 | 1.07 (1.06–1.09) | 1.21 (1.18–1.24) | 1.37 (1.32–1.42) | 1.55 (1.47–1.63) |
| Subjects without cardiovascular diseases and cancer at baseline | 10 | 44,998 | 1.23 (1.10–1.37) | 1.14 (1.06–1.22) | 1.05 (1.02–1.09) | 1.00 | 1.04 (1.02–1.05) | 1.11 (1.08–1.15) | 1.19 (1.14–1.25) | 1.28 (1.21–1.36) |
| Country | ||||||||||
| Asia | 18 | 21,640 | 1.07 (0.94–1.22) | 1.05 (0.95–1.16) | 1.00 (0.97–1.04) | 1.00 | 1.11 (1.08–1.13) | 1.36 (1.28–1.43) | 1.70 (1.55–1.85) | 2.12 (1.87–2.40) |
| Europe | 9 | 20,186 | 1.31 (1.15–1.49) | 1.18 (1.08–1.29) | 1.07 (1.02–1.12) | 1.00 | 1.05 (1.00–1.11) | 1.15 (1.03–1.28) | 1.26 (1.07–1.48) | — |
| USA | 8 | 90,732 | 1.11 (1.07–1.14) | 1.06 (1.04–1.09) | 1.02 (1.01–1.03) | 1.00 | 1.02 (1.01–1.03) | 1.07 (1.05–1.19) | 1.11 (1.09–1.14) | 1.16 (1.12–1.20) |
| Sex | ||||||||||
| Men | 12 | 39,440 | 1.12 (1.02–1.21) | 1.07 (1.01–1.13) | 1.03 (1.00–1.06) | 1.00 | 1.04 (1.02–1.06) | 1.14 (1.10–1.18) | 1.25 (1.18–1.31) | 1.37 (1.28–1.47) |
| Women | 12 | 70,175 | 1.07 (1.02–1.12) | 1.04 (1.01–1.07) | 1.01 (1.00–1.03) | 1.00 | 1.06 (1.05–1.07) | 1.18 (1.15–1.21) | 1.33 (1.28–1.38) | 1.49 (1.41–1.57) |
| Both | 12 | 37215 | 1.07 (0.97–1.18) | 1.04 (0.97–1.11) | 1.00 (0.97–1.04) | 1.00 | 1.09 (1.05–1.12) | 1.20 (1.13–1.28) | 1.33 (1.21–1.46) | — |
| Mean age | ||||||||||
| >60 years | 19 | 45,824 | 1.04 (0.96–1.13) | 1.02 (0.96–1.08) | 1.00 (0.97–1.03) | 1.00 | 1.11 (1.08–1.13) | 1.36 (1.30–1.44) | 1.71 (1.57–1.87) | 2.14 (1.90–2.42) |
| ≤60 years | 17 | 101,006 | 1.11 (1.07–1.15) | 1.07 (1.04–1.09) | 1.02 (1.01–1.04) | 1.00 | 1.05 (1.04–1.06) | 1.15 (1.12–1.17) | 1.25 (1.22–1.29) | 1.37 (1.31–1.43) |
| Follow-up duration | ||||||||||
| ≥10 years | 20 | 54,615 | 1.15 (1.07–1.23) | 1.09 (1.03–1.14) | 1.03 (1.00–1.05) | 1.00 | 1.09 (1.07–1.11) | 1.25 (1.21–1.29) | 1.44 (1.36–1.52) | 1.66 (1.54–1.78) |
| <10 years | 16 | 92,215 | 1.00 (0.95–1.06) | 1.00 (0.96–1.03) | 0.99 (0.97–1.01) | 1.00 | 1.09 (1.06–1.11) | 1.24 (1.18–1.29) | 1.42 (1.33–1.52) | 1.64 (1.49–1.79) |
| Sleep assessment | ||||||||||
| Self- administered | 21 | 134,427 | 1.11 (1.06–1.16) | 1.06 (1.03–1.10) | 1.02 (1.00–1.04) | 1.00 | 1.05 (1.04–1.06) | 1.14 (1.13–1.16) | 1.26 (1.23–1.29) | 1.38 (1.34–1.42) |
| Interviewer- administered | 15 | 12,403 | 1.09 (0.97–1.21) | 1.05 (0.98–1.13) | 1.02 (0.98–1.05) | 1.00 | 1.07 (1.04–1.11) | 1.21 (1.12–1.31) | 1.37 (1.22–1.54) | — |
| Adjusted for … Education/socioeconomic status | ||||||||||
| Yes | 27 | 143,711 | 1.06 (1.02–1.11) | 1.03 (1.01–1.06) | 1.01 (0.99–1.02) | 1.00 | 1.09 (1.08–1.11) | 1.25 (1.21–1.28) | 1.43 (1.37–1.49) | 1.64 (1.55–1.74) |
| No | 9 | 3,119 | 1.15 (0.95–1.38) | 1.09 (0.96–1.23) | 1.04 (0.97–1.10) | 1.00 | 1.03 (0.99–1.07) | 1.11 (1.02–1.20) | 1.20 (1.06–1.36) | — |
| Smoking | ||||||||||
| Yes | 28 | 143,178 | 1.07 (1.02–1.12) | 1.04 (1.01–1.07) | 1.01 (0.99–1.02) | 1.00 | 1.10 (1.08–1.11) | 1.26 (1.22–1.30) | 1.45 (1.38–1.51) | 1.66 (1.57–1.77) |
| No | 8 | 3,652 | 1.28 (1.03–1.60) | 1.17 (1.01–1.36) | 1.07 (1.00–1.16) | 1.00 | 1.02 (0.97–1.06) | 1.09 (0.99–1.20) | 1.18 (1.02–1.38) | — |
| Alcohol | ||||||||||
| Yes | 24 | 56,831 | 1.08 (1.00–1.16) | 1.04 (0.99–1.10) | 1.01 (0.98–1.03) | 1.00 | 1.11 (1.09–1.13) | 1.29 (1.24–1.34) | 1.51 (1.42–1.60) | 1.76 (1.63–1.91) |
| No | 12 | 89,999 | 1.12 (.08–1.16) | 1.07 (1.04–1.09) | 1.02 (1.01–1.03) | 1.00 | 1.02 (1.01–1.03) | 1.08 (1.06–1.10) | 1.14 (1.11–1.17) | 1.20 (1.16–1.24) |
| Physical activity | ||||||||||
| Yes | 25 | 142,638 | 1.07 (1.03–1.10) | 1.04 (1.02–1.06) | 1.01 (1.00–1.02) | 1.00 | 1.09 (1.08–1.10) | 1.25 (1.21–1.28) | 1.42 (1.37–1.48) | 1.63 (1.54–1.72) |
| No | 11 | 4,192 | 1.27 (1.01–1.59) | 1.17 (1.00–1.35) | 1.07 (0.99–1.16) | 1.00 | 1.01 (0.95–1.07) | 1.10 (0.98–1.24) | 1.22 (1.02–1.46) | — |
| Health statusb | ||||||||||
| Yes | 10 | 105,645 | 1.06 (1.02–1.10) | 1.02 (1.00–1.05) | 0.99 (0.98–1.00) | 1.00 | 1.09 (1.07–1.11) | 1.23 (1.18–1.28) | 1.39 (1.31–1.47) | 1.57 (1.46–1.69) |
| No | 26 | 41,195 | 1.11 (1.03–1.21) | 1.07 (1.01–1.13) | 1.03 (1.00–1.05) | 1.00 | 1.06 (1.04–1.08) | 1.20 (1.15–1.26) | 1.38 (1.29–1.48) | 1.59 (1.44–1.75) |
| Blood pressure | ||||||||||
| Yes | 22 | 112,841 | 1.06 (1.02–1.11) | 1.03 (1.01–1.06) | 1.01 (1.00–1.02) | 1.00 | 1.06 (1.04–1.08) | 1.18 (1.14–1.21) | 1.31 (1.25–1.38) | 1.47 (1.38–1.57) |
| No | 14 | 33,989 | 1.13 (1.00–1.28) | 1.08 (0.99–1.17) | 1.03 (0.99–1.07) | 1.00 | 1.07 (1.04–1.10) | 1.19 (1.13–1.26) | 1.33 (1.23–1.45) | — |
| Body mass index | ||||||||||
| Yes | 26 | 142,963 | 1.06 (1.01–1.11) | 1.03 (1.00–1.06) | 1.00 (0.99–1.02) | 1.00 | 1.09 (1.08–1.11) | 1.25 (1.22–1.29) | 1.44 (1.38–1.50) | 1.65 (1.56–1.74) |
| No | 10 | 3,867 | 1.27 (1.06–1.52) | 1.16 (1.03–1.31) | 1.07 (1.00–1.13) | 1.00 | 1.07 (1.02–1.12) | 1.30 (1.13–1.50) | 1.62 (1.27–2.06) | — |
| Preexisting chronic diseases | ||||||||||
| Yesc | 32 | 145,917 | 1.07 (1.03–1.12) | 1.04 (1.01–1.07) | 1.01 (0.99–1.02) | 1.00 | 1.09 (1.08–1.10) | 1.24 (1.21–1.27) | 1.41 (1.37–1.46) | 1.61 (1.54–1.69) |
| No | 4 | 913 | — | 1.03 (0.82–1.29) | 1.00 (0.88–1.12) | 1.00 | 1.16 (1.07–1.27) | 1.44 (1.23–1.69) | — | — |
| Sleep disorders/sleeping pills | ||||||||||
| Yesd | 13 | 91,999 | 1.11 (1.06–1.15) | 1.07 (1.04–1.10) | 1.03 (1.01–1.04) | 1.00 | 1.03 (1.01–1.05) | 1.09 (1.05–1.12) | 1.15 (1.09–1.21) | 1.21 (1.13–1.30) |
| No | 23 | 54,831 | 1.11 (1.03–1.21) | 1.07 (1.01–1.13) | 1.02 (1.00–1.05) | 1.00 | 1.06 (1.04–1.07) | 1.19 (1.15–1.22) | 1.33 (1.27–1.40) | 1.50 (1.41–1.60) |
| Depression/mental health | ||||||||||
| Yes | 15 | 25,634 | 1.02 (0.95–1.10) | 1.01 (0.96–1.06) | 1.00 (0.97–1.02) | 1.00 | 1.11 (1.09–1.14) | 1.38 (1.29–1.47) | 1.74 (1.56–1.92) | 2.18 (1.89–2.52) |
| No | 21 | 121,196 | 1.14 (1.06–1.22) | 1.07 (1.03–1.13) | 1.02 (0.99–1.04) | 1.00 | 1.11 (1.08–1.13) | 1.29 (1.24–1.35) | 1.51 (1.42–1.61) | 1.77 (1.63–1.93) |
| Study quality | ||||||||||
| 7–8 stars | 13 | 50,899 | 1.17 (1.08–1.26) | 1.10 (1.04–1.16) | 1.03 (1.01–1.06) | 1.00 | 1.07 (1.05–1.09) | 1.18 (1.14–1.22) | 1.29 (1.23–1.36) | 1.42 (1.33–1.51) |
| 4–6 stars | 23 | 95,931 | 1.02 (0.97–1.07) | 1.01 (0.97–1.04) | 0.99 (0.98–1.01) | 1.00 | 1.10 (1.08–1.12) | 1.32 (1.27–1.38) | 1.62 (1.51–1.74) | 1.98 (1.79–2.18) |
aN: number of studies (gender specific studies).
bHealth status (self-reported or physical functioning).
cIncludes studies with subjects of no chronic diseases (cardiovascular diseases and cancer) at baseline.
dIncludes studies with subjects who did not take sleeping pills at baseline.