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. Author manuscript; available in PMC: 2013 Aug 28.
Published in final edited form as: Sleep Med Rev. 2007 Jul 10;11(5):341–360. doi: 10.1016/j.smrv.2007.03.010

Table 1.

Epidemiologic association of self-reported long sleep with mortality

Citation Population studied
(1. N, 2. Ages, 3.
Years Study Duration)		 Number of
covariates
besides
age		 Age-adjusted mortality rates
RR: Relative Risk (95% confidence
interval, when available)		 Mortality rates adjusted for all covariates
RR: Relative Risk (95% confidence interval)
Amagai et al.18

  1. 11,325 (4419 men, 6906 women)

  2. 19–93

  3. 9

 8 RR (ref 7–7.9 h; men, women)
<6h: 2.3 (1.3, 3.9), 0.8 (0.3, 2.2)
6–6.9h: 1.1 (0.7, 1.8), 1.3 (0.8, 2.0)
7–7.9h: 1.0, 1.0
8–8.9h: 1.0 (0.7, 1.3), 1.0 (0.7, 1.5)
>=9h: 1.3 (0.9, 1.8), 1.5 (1.0, 2.3)		 RR (ref 7–7.9 h; men, women)
<6h: 2. 4 (1.3, 4.2), 0.7 (0.2, 2.3)
6–6.9h: 1.1 (0.7, 1.8), 1. 3 (0.8, 2.1)
7–7.9h: 1,0, 1.0
8–8.9h: 0.9 (0.6, 1.2), 1. 1 (0.8, 1.6)
>=9h: 1.1 (0.8, 1.6), 1.5 (1.0, 2.4)
Ayas et al.42

  1. 71,617 women

  2. 45–65

  3. 10

 15 Fatal Coronary Heart Disease
RR (Ref 8 h)
<=5h: 1.67 (1.02–2.74)
6h: 1.05 (0.75–1.46)
7h: 0.80 (0.58–1.09)
8h: 1.00
>=9h: 1.71 (1.05–2.77)		 Fatal Coronary Heart Disease
RR (Ref 8 h)
<=5h: 1.12 (0.68–1.84)
6h: 0.91 (0.65–1.28)
7h: 0.83 (0.60–1.14)
8h: 1.00
>=9h: 1.45 (0.89–2.36)
Breslow &
Enstrom19

  1. 6,928

  2. >18

  3. 9.5

 0 Mortality Rates
Women Men
<=6h: 0.097 0.156
7h: 0.068 0.115
8h: 0.084 0.111
>=9h: 0.104 0.139
Burazeri et al.9

  1. 1,842 (1,001 women, 841 men)

  2. >=50

  3. 9–11

 24 All-Cause Mortality
Night Sleep RR (ref 6h)		 All-Cause Mortality
Night Sleep RR (ref 6h)
Women Men Women Men
<6h: 1.00 1.00 <6h: 1.00 1.00
6–8h: 0.82 1.21 6–8h: 0.80 1.25
(0.57–1.17) (0.83–1.76) (0.54–1.17) (0.83–1.87)
>8h: 0.95 1.86 >8h: 1.08 1.91
(0.63–1.42) (1.19–2.91) (0.70–1.66) (1.16–3.13)
Night Sleep + Napping
RR (ref 6h)		 Night Sleep + Napping
RR (ref 6h)
Women Men Women Men
<6h: 1.00 1.00 <6h: 1.00 1.00
6–8h: 0.68 1.03 6–8h: 0.64 1.41
(0.46–1.01) (0.65–1.64) (0.42–0.97) (0.83–2.39)
>8h: 0.84 1.81 >8h: 0.80 2.13
(0.56–1.27) (1.12–2.93) (0.51–1.24) (1.23–3.71)
Chen &
Foley10

  1. 10,287

  2. 32–86

  3. 4

 6 With no control for age or other
covariates:
All-Cause Mortality
Mortality Rate (ref: 6–9h)		 No significant effect.
Data not reported
Subjects >=60 years
<6h or >9h = 20%
6–9hr = 14.7%
Subjects <60 yrs:
No Significant Effect
Gale & Martyn11

  1. 1,299

  2. >=65

  3. 23

 9 All-Cause Mortality. RR (ref 9h)
<=7h: 1.1 (0.8–1.4)
8h: 0.9 (0.7–1.0)
9h: 1.0
10h: 1.2 (1.0–1.4)
11h: 1.5 (1.2–1.8)
>=12h: 1.9 (1.4–2.5)		 All-Cause Mortality
RR (ref 9h)
<=7h: 1.0 (0.7–1.4)
8h: 0.8 (0.7–1.0)
9h: 1.0
10 h: 1.2 (1.0–1.4)
11 h: 1.3 (1.0–1.7)
>=12h: 1.7 (1.2–2.5)
Gottlieb
et al.12

  1. 4,541 (2,532 women, 2009 men)

  2. not reported

  3. 14

 5 Not Reported All-Cause Mortality
RR (ref 7–8h)
Women Men
<6=1.70 1.40
6= 1.20 0.80
7–8=1.00 1.00
9=0.95 1.30
>9=1.8 1.5
Hammond6

  1. 1,064,004

  2. <30 to >=80

  3. 3

 0 Death rate per 100 people
lowest for 7 hrs in 17/18 age/gender
groups
Heslop et al.23

  1. 3030 (442 women, 2588 men)

  2. Men <65, women <60

  3. 25

 10 Cardiovascular deaths
RR (ref “always 7–8h”)		 Cardiovascular deaths
RR (ref “always 7–8h”)
Women Men Women Men
Always <7h:
2.32 (0.99, 5.42)		 1.33 (1.01,1.76) Always <7h:
2.30 (0.94,5.60)		 1.19 (0.90,1.58)
Always >8h:
1.67 (0.22,1.25)		 0.73 (0.35,15.5) Always >8h:
1.53 (0.20,1.18)		 0.63 (0.30,13.4)
Increase over time:
0.27 (0.04,2.00)		 0.82 (0.59,1.13) Increase over time:
0.34 (0.04,2.56)		 0.72(0.52,1.01)
Decrease over time:
1.15 (0.47,2.84)		 1.07 (0.82,1.39) Decrease over time:
1.34 (0.53,1.25)		 0.88 (0.67,1.16)
All-cause mortality
RR (ref 7–8h)		 All-cause mortality
RR (ref 7–8h)
Always <7h:
1.99 (1.16,3.41)		 1.30 (1.06,1.61) Always <7h:
1.73 (0.99,3.03)		 1.15(0.99,1.42)
Always >8h:
0.60 (0.08,4.37)		 1.04 (0.65,1.66) Always >8h:
0.58 (0.08,4.22)		 0.91 (0.57,1.46)
Increase over time:
0.49 (0.20,1.23)		 0.91 (0.72,1.15) Increase over time:
0.47 (0.19,1.20)		 0.81 (0.64,1.02)
Decrease over time:
0.91 (0.50,1.66)		 1.17 (0.46,1.42) Decrease over time:
0.98 (0.53,1.79)		 1.00 (0.82,1.21)
Huppert &
Whittington13

  1. 6,096

  2. >=18

  3. 7

 Not
reported		 All-Cause Mortality
RR (Ref 6–9h)
Women:
NS, data not reported
Men
<6h: 0.95
6–9h: 1.0
>9h: 2.25
Kaplan19

  1. 6,928

  2. 60–94

  3. 17

 6 All-Cause Mortality
RR (ref 7–8h)
Sleeping >7–8 hr or <7–8 hrs
Ages 38–49=1.23 (0.88–1.70)
Ages 50–59=1.44 (1.08–1.91)
Ages 60–69=0.95 (0.73–1.24)
Ages >=70=1.05 (0.85–1.29)
7–8 hrs per night not associated with
different risk ratio vs not sleeping 7- 8 hrs
across all groups.
Kojima et al.14

  1. 5,322

  2. 20–67

  3. 12

 10 All-Cause Mortality
RR (ref 7–8.9h)		 All-Cause Mortality
RR (ref:7–8.9h)
Women Men Women Men
<6.9h: 0.92 1.90 <6.9h: 0.90 1.93
(0.53–1.62) (1.10–3.29) (0.50–1 61) (1.12–3.35)
7–8.9h: 1.00 1.00 7–8.9h: 1.00 1.00
9–9.9h: 1.10 1.13 9–9.9h: 1.07 1.15
(0.61–2.00) (0.73–1.74) (0.58–1.95) (0.74–1.77)
>=10h: 0.42 1.94 >=10h: 0.40 1.77
(0.06–3.02) (1.01–3.76) (0.06–2.92) (0.88–3.54)
Kripke et al.21

  1. 823,065

  2. 30 to >90 yrs

  3. 6

 5 All-Cause Mortality
RR (ref 7–7.9h)
Women Men
<4h: 1.48 2.80
4–4.9h: 1.40 1.59
5–5.9h: 1.20 1.38
6–6.9h: 1.13 1.11
7–7.9h: 1.00 1.00
8–8.9h: 1.13 1.10
9–9.9h: 1.27 1.29
>=10 h: 1.82 1.77
Similar trends for Mortality Associated with
CHD, stroke, cancer, suicide. Similar trends
across multiple age-groups
Kripke et al.5

  1. 1,116,936 (636,095 women, 480,841 men)

  2. 30–102

  3. 6

 32 All-Cause Mortality
RR (ref 7 hr)
Women Men
2.5–3.4h: 1.33 1.19
(1.08–1.64) (0.96–1.47)
3.5–4.4h: 1.11 1.17
(1.01–1.22) (1.06–1.28)
4.5–5.4h: 1.07 1.11
(1.01–1.13) (1.05–1.18)
5.5–6.4h: 1.07 1.08
(1.03–1.11) (1.04–1.11)
6.5–7.4h: 1.00 1.00
7.5–8.4h: 1.13 1.12
(1.09–1.16) (1.09–1.15)
8.5–9.4h: 1.23 1.34
(1.17–1.28) (1.28–1.40)
>=10 h: 1.41 1.34
(1.34–1.50) (1.28–1.40)
Mallon et al.24

  1. 1,870 (964 women, 906 men)

  2. 45–65

  3. 12

 17 All-Cause Mortality
RR (ref 6–8h)		 “Not Significant”
Data Not Reported
Women Men Similar patterns for mortality associated with
coronary artery disease, cancer, and all other
causes.
<6h: 1.0 1.1
(0.6–1.8) (0.6–7.0)
6–8h: 1.0 1.0
>8h: 1.3 2.0
(0.6–2.6) (1.2–3.2)
Patel et al.15

  1. 82,969 women

  2. 40–65

  3. 10

 11 All-Cause Mortality
RR (ref 7h)
<5h: 1.41 (1.25–1.58)
6h: 1.07 (1.00–1.15)
7h: 1.00
8h: 1.18 (1.10–1.26)
>=9h: 1.72 (1.55–1.91)		 All-Cause Mortality
RR (ref 7h)
<5h: 1.08 (0.96–1.22)
6h: 0.99 (0.92–1.06)
7h: 1.00
8h: 1.11 (1.03–1.19)
>=9h: 1.40 (1.25–1.55)
ollak et al.16

  1. 1,855 (1,510 women, 783 men)

  2. 65–98

  3. 3.5

 10 All-Cause Mortality
Mortality Rate (per 100)		 Cox regression models not significant for
Males or females.
Women Men Data not available for specific hrs of sleep.
<=4h: 19 24
5h: 7 25
6h: 14 16
7h: 8 16.5
8h: 13 22
>=9h: 18 30
Qureshi et al.17

  1. 7,844

  2. 32 to >72

  3. 10

 9 All-Cause Mortality.
RR (ref 6–8h)
6–8h: 1.0
>8h: 1.3 (1.1–1.5)
Risk of Stroke
RR (ref 6–8 hr)
6–8h: 1.0
>8h: 1.9 (1.2–3.1)
Tamakoshi &
Ohno8

  1. 104,298 (60,276 women, 44,022 men)

  2. 40–79

  3. 10

 14 All-Cause Mortality
RR (ref 7–7.9 hr)		 All-Cause Mortality
RR (ref 7–7.9 hr)
Women Men Women Men
<7h: 1.08 1.13 <7h: 1.14 1.12
(0.99–1.17) (1.04–1.22) (0.99–1.32) (0.98–1.28)
7–7.9h: 1.00 1.00 7–7.9h: 1.00 1.00
8–8.9h: 1.24 1.13 8–8.9h: 1.20 1.18
(1.14–1.34) (1.06–1.20) (1.05–1.38) (1.06–1.31)
>=9h: 1.64 1.52 >=9h: 1.62 1.49
(1.49–1.80) (1.42–1.64) (1.36–1.92) (1.31–1.70)
Wingard et al.22

  1. 6,928 (2,496 women, 2,229 men)

  2. 30–69

  3. 9

 14 All-Cause Mortality
% Mortality (ref 7–8h)		 In multiple logistic analysis with all
covariates, sleep had significant
independent association with mortality.
Women Men
7–8 h:    5.5% 8.2%
<=6 h or >=9: 8.8% 13.6%

This table is adapted from the summary table previously published by Youngstedt and Kripke1.