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. Author manuscript; available in PMC: 2011 Jun 1.
Published in final edited form as: Sleep Med Rev. 2009 Nov 25;14(3):191–203. doi: 10.1016/j.smrv.2009.07.006

Table 2.

Odds Ratios and Mortality Rates in Studies of Sleep Duration and Mortality Across the World

First Author Stratum Sleep Duration (hrs) Odds Ratio (least adjusted) 95% CI Odds Ratio (fully adjusted) 95% CI Mortality rate (%)
Amagai 2004 (Asia) Men: <6 2.3 1.3– 3.9 2.4 1.3–4.2 1.56
6 1.1 0.7– 1.8 1.1 0.7–1.8 0.60
7 1.0 Reference 1.0 Reference 0.59
8 1.0 0.7–1.3 0.9 0.6–1.2 0.68
≥9 1.3 0.9–1.8 1.1 0.8–1.6 1.27
Women: <6 0.8 0.3–2.2 0.7 0.2–2.3 0.19
6 1.3 0.8–2.0 1.3 0.8–2.1 0.31
7 1.0 Reference 1.0 Reference 0.26
8 1.0 0.7–1.5 1.1 0.8–1.6 0.37
≥9 1.5 1.0–2.3 1.5 1.0–2.4 0.79
Ayas 2003 (North America) Men & Women: ≤5 1.67 1.02–2.74 1.12 0.68–1.84
6 1.05 0.75–1.46 0.91 0.65–1.28
7 0.80 0.58–1.09 0.83 0.60–1.14
8 1.0 Reference 1.0 Reference
≥9 1.71 1.05–2.77 1.45 0.89–2.36
Belloc 1973 (North America) Men: ≤6 0.09
7 0.63
8 0.57
≥9 0.66
Women: ≤6 0.04
7 0.36
8 0.46
≥9 0.66
Branch 1984 (North America) Men: 7–8 1.0 Reference 0.22
<7 or >8 1.60 0.94–2.28 0.31
Women: 7–8 1.0 Reference 0.17
<7 or >8 1.34 0.85–1.83 0.22
Breslow 1980 (North America) Men: ≤6 0.16
7 0.12
8 0.11
≥9 0.14
Women: ≤6 1.0
7 0.7
8 0.8
≥9 1.0
Burazeria 2003 (Asia and Africa) Men (night): <6 1.0 Reference 1.0 Reference
6–8 1.21 0.83–1.76 1.25 0.83–1.87
>8 1.86 1.19–2.91 1.91 1.16–3.13
Men (24h): <6 1.0 Reference 1.0 Reference
6–8 1.03 0.65–1.64 1.41 0.83–2.39
>8 1.81 1.12–2.93 2.13 1.23–3.71
Women (night): <6 1.0 Reference 1.0 Reference
6–8 0.82 0.57–1.17 0.80 0.54–1.17
>8 0.95 0.63–1.42 1.08 0.70–1.66
Women (24h): <6 1.0 Reference 1.0 Reference
6–8 0.68 0.46–1.01 0.64 0.42–0.97
>8 0.84 0.56–1.27 0.80 0.51–1.24
Chen 1994 (North America) Age ≥60: <6 or >9 0.20
6–9 0.15
Age <60: <6 or >9 .02
6–9 .02
Ferrieb 2007 (Europe) Time 1: ≤ 5 1.61 1.20–2.15 1.24 0.92–1.67 9.54
6 1.11 0.91–1.35 1.00 0.82–1.22 6.05
7 1.0 Reference 1.0 Reference 5.24
8 1.08 0.85–1.38 1.07 0.84–1.36 5.51
≥9 1.77 0.84–3.76 1.54 0.72–3.28 7.87
Time 2: ≤ 5 2.07 1.38–3.13 1.78 1.17–2.71 6.90
6 1.21 0.89–1.66 1.13 0.83–1.55 3.75
7 1.0 Reference 1.0 Reference 3.20
8 1.13 0.85–1.52 1.11 0.82–1.48 3.79
≥9 2.00 1.18–3.38 1.95 1.15–3.31 6.90
Change from baseline: No Chg 1.0 Reference 1.0 Reference
Incr. 5–6 0.88 0.60–1.28 0.92 0.63–1.5 4.14
Incr. 7–8 1.84 1.31–2.58 1.75 1.24–2.47 5.09
Decr. 6–8 1.72 1.25–2.38 1.62 1.17–2.25 4.65
Gale 1998 (Europe) Men & Women: ≤7 1.0 0.7–1.4
8 0.8 0.7–1.0
9 1.0 Reference
10 1.2 1.0–1.4
11 1.3 1.0–1.7
≥12 1.7 1.2–2.5
Gangwischc 2008 (North America) All Ages: ≤ 5 1.17 0.99–1.39
6 0.95 0.81–1.11
7 1.0 Reference
8 1.23 1.08–1.39
≥9 1.34 1.15–1.56
Age <60: ≤ 5 0.67 0.43–1.05
6 0.75 0.53–1.08
7 1.0 Reference
8 1.02 0.75–1.38
≥9 1.04 0.66–1.65
Age >60: ≤ 5 1.26 1.06–1.53
6 0.98 0.83–1.17
7 1.0 Reference
8 1.25 1.09–1.44
≥9 1.36 1.15–1.60
Goto 2003 (Asia) Men & Women: <6 1.42 0.61–3.27 1.29 0.50–3.24
6–7 Ref Reference 1.0 Reference
>7 1.62 0.99–3.26 1.54 0.97–2.58
Gottlieb 2002 (North America) Men: <6 1.4 None reported
6 0.8
7–8 1.0
9 1.3
>9 1.5
Women: <6 1.7 None reported
6 1.1
7–8 1.0
9 0.9
>9 1.8
Hammond 1964d (North America) Men, Time 1: <4 6.70
4 3.13
5 2.08
6 1.27
7 0.96
8 1.18
9 1.54
≥10 3.15
Men, Time 2: <4 5.17
4 2.91
5 1.99
6 1.67
7 1.44
8 1.59
9 1.91
≥10 2.87
Heslop 2002 (Europe) Men: <7 1.30 1.06–1.61 1.15 0.93–1.42
7–8 1.0 Reference 1.0 Reference
>8 1.04 0.65–1.66 0.91 0.57–1.46
Women: <7 1.99 1.16–3.41 1.73 0.99–3.03
7–8 1.0 Reference 1.0 Reference
>8 0.60 0.08–4.37 0.58 0.08–4.22
Hublin 2007 (Europe) Men: <7 1.34 1.19–1.51 1.26 1.11–1.43
7–8 1.0 Reference 1.0 Reference
>8 1.32 1.17–1.48 1.24 1.09–1.41
Women: <7 1.12 0.98–1.28 1.21 1.05–1.40
7–8 1.0 Reference 1.0 Reference
>8 1.20 1.06–1.35 1.17 1.03–1.34
Huppert 1995 (Europe) Men & Women: <6 0.95
6–9 1.0
>9 2.25
Kaplan 1987 (North America) Age 38–49: 7–8 1.0 Reference
<7 or >8 1.23 0.88–1.70
Age 50–59: 7–8 1.0 Reference
<7 or >8 1.44 1.08–1.91
Age 60–60: 7–8 1.0 Reference
<7 or >8 0.95 0.73–1.24
Age ≥70: 7–8 1.0 Reference
<7 or >8 1.05 0.85–1.29
Kojima 2000 (Asia) Men: <7 1.9 1.1–3.29 1.93 1.12–3.35
7–8.9 1.0 Reference 1.0 Reference
9–9.9 1.13 0.73–1.74 1.15 0.74–1.77
≥10 1.94 1.01–3.76 1.77 0.88–3.54
Women: <7 0.92 0.53–1.62 0.90 0.50–1.61
7–8.9 1.0 Reference 1.0 Reference
9–9.9 1.10 0.61–2.00 1.07 0.58–1.95
≥10 0.42 0.06–3.02 0.40 0.06–2.92
Kripke 1979 (North America) Mortality Ratios Men: <4 2.8 None reported
4–4.9 1.59
5–5.9 1.38
6–6.9 1.11
7–7.9 1.0
8–8.9 1.10
9–9.9 1.29
≥10 1.77
Women: <4 1.48 None reported
4–4.9 1.40
5–5.9 1.20
6–6.9 1.13
7–7.9 1.0
8–8.9 1.13
9–9.9 1.27
≥10 1.82
Kripke 2002 (North America) (Mortality Hazard Ratios) Men: 3 1.19 0.96–1.47
4 1.17 1.06–1.28
5 1.11 1.05–1.18
6 1.08 1.04–1.11
7 1.0 Reference
8 1.12 1.09–1.15
9 1.17 1.13–1.21
≥10 1.34 1.28–1.40
Women: 3 1.33 1.08–1.64
4 1.11 1.01–1.22
5 1.07 1.01–1.13
6 1.07 1.03–1.11
7 1.0 Reference
8 1.13 1.09–1.16
9 1.23 1.17–1.28
≥10 1.41 1.34–1.50
Lan 2007 (Asia) Men: <7 0.97 0.76–1.23 0.98 0.76–1.25
7–7.9 1.0 Reference 1.0 Reference
8–8.9 1.11 0.91–1.36 1.09 0.89–1.33
9–9.9 1.33 1.08–1.65 1.14 0.91–1.42
≥10 1.86 1.48–2.34 1.51 1.19–1.92
Women: <7
7–7.9
8–8.9
9–9.9
≥10
Mallon 2002 (Europe) Men: <6 1.1 0.6–7.0
7–8 1.0 Reference
>8 2.0 1.2–3.2
Women: <6 1.0 0.6–1.8
7–8 1.0 Reference
>8 1.3 0.6–2.6
Patel 2004 (North America) Women: ≤5 1.41 1.25–1.58 1.08 0.96–1.22
6 1.07 1.0–1.15 0.99 0.92–1.06
7 1.0 Reference 1.0 Reference
8 1.18 1.1–1.26 1.11 1.03–1.19
≥9 1.72 1.55–1.91 1.40 1.25–1.55
Pollak 1990 (North America) Men: ≤4 0.24
5 0.25
6 0.16
7 0.17
8 0.22
≥9 0.30
Women: ≤4 0.19
5 0.07
6 0.14
7 0.08
8 0.13
≥9 0.18
Qureshi 1997 (North America) Stroke: 6–8 1.0 Reference 1.0 Reference
<6 1.0 0.7–1.5 1.0 0.70–1.5
>8 1.5 1.1–2.1 1.5 1.1–2.0
CV Disease: 6–8 1.0 Reference 1.0 Reference
<6 1.3 0.9–1.7 1.3 1.0–1.8
>8 1.2 0.9–1.6 1.2 0.8–1.5
Ruigomez 1995 (Europe) Men: <7 1.06 0.61–1.83
7–9 1.0 Reference
>9 1.30 0.71–2.38
Women: <7 0.66 0.37–1.16
7–9 1.0 Reference
>9 1.46 0.79–2.70
Rumble 1992 (Europe) Men & Women: <4 1.12 0.47–2.69
≥10 1.60 0.74–3.47
Shankar 2008 (Asia) Men: ≤5 1.7 1.35–2.15
6 1.20 0.99–1.45
7 1.0 Reference
8 1.1 0.92–1.32
≥9 1.88 1.48–2.40
Women: <5 1.43 1.09–1.88
6 1.04 0.82–1.31
7 1.0 Reference
8 1.15 0.92–1.44
≥9 1.67 1.24–2.27
Suzuki 2008 (Asia) Men: <7 1.03 0.97–1.09
7–8 1.0 Reference
≥9 1.32 1.26–1.40
Women: <7 0.99 0.94–1.05
7–8 1.0 Reference
≥9 1.42 1.22–1.52
Tamakoshi 2004 (Asia) Men: ≤4 1.62 1.26–2.09 0.88 0.44–1.78
5 1.16 1.01–1.33 1.07 0.83–1.38
6 1.09 1.0–1.19 1.11 0.95–1.28
7 1.0 Reference 1.0 Reference
8 1.11 1.05–1.19 1.19 1.07–1.32
9 1.26 1.15–1.37 1.27 1.08–1.48
≥10 1.73 1.58–1.90 1.75 1.46–2.09
Women: ≤4 1.60 1.28–2.02 1.83 1.20–2.81
5 1.14 0.99–1.31 1.18 0.90–1.53
6 1.05 0.96–1.15 1.17 0.99–1.39
7 1.0 Reference 1.0 Reference
8 1.23 1.14–1.33 1.35 1.17–1.56
9 1.35 1.20–1.51 1.57 1.26–1.96
≥10 1.92 1.70–2.17 2.12 1.67–2.68
Tsubono 1993 (Asia) Men & Women: ≤6 1.26 0.81–1.97
7–8 1.0 Reference
>9 1.58 1.16–2.15
Wingard 1982 (North America) Men & Women: ≤6 or ≥9 1.13 1.1–1.7
7–8 1.0 Reference
Men: ≤6 or ≥9 0.14
7–8 0.08
Women: ≤6 or ≥9 0.09
7–8 0.06
Wingard 1983 (North America) Men: ≤6 RR=1.3e 14.8
7–8 8.2
≥9 11.1
Women: ≤6 9.0
7–8 5.6
≥9 8.5
a

risk was separately calculated for nighttime sleep (ngt) and total sleep across 24 hours (24h)

b

risk reported at two time points (Time 1) and (Time 2) followed by risk associated with change in sleep duration from baseline (Change): no change (No chg), increase from 5–6 hours (Incr. 5–6), increase from 7–8h (Incr. 7–8), or decrease from 6, 7 or 8 hours (Decr. 6–8)

c

risk was calculated for the total sample (total), as well as separately for those aged <60 years (Age <60) and those 60 or older (Age ≥60)

d

rates were separately calculated for 9 age groups; those presented are means weighted based on number in each age group

e

relative risk for males & females not sleeping 7–8 hrs= 1.3 (p=0.04)

Note: risks reported in bold font represent statistically significant risks