Table 4.
Hazard ratios for all-cause and cause specific mortality in relation to self-reported sleep duration among 73,749 women in the Multiethnic Cohort Study, 1993-2007a,b
| Outcomec | Deaths |
Daily sleeping |
|||||
|---|---|---|---|---|---|---|---|
| ≤5 hr |
6 hr |
7 hr |
8 hr |
≥9 hr |
|||
| No. | % | HR (95% CI) | HR (95% CI) | HR | HR (95% CI) | HR (95% CI) | |
| All Causes | 8,597 | - | 1.14 (1.06-1.23)* | 1.05 (0.99-1.12) | 1.00 | 1.02 (0.96-1.08) | 1.22 (1.13-1.31)* |
| Malignant Neoplasms | 3,055 | 35.5 | 1.10 (0.97-1.25) | 1.03 (0.94-1.14) | 1.00 | 0.97 (0.88-1.07) | 0.99 (0.87-1.14) |
| Cardiovascular disease | 2,838 | 33.0 | 1.20 (1.05-1.36)* | 1.06 (0.96-1.18) | 1.00 | 1.08 (0.98-1.20) | 1.29 (1.13-1.47)* |
| Coronary Heart Disease | 1,380 | 16.1 | 1.18 (0.98-1.42) | 1.13 (0.97-1.31) | 1.00 | 1.12 (0.96-1.29) | 1.23 (1.02-1.49)* |
| Myocardial Infarction | 521 | 6.1 | 1.18 (0.87-1.59) | 1.23 (0.96-1.56) | 1.00 | 1.10 (0.86-1.40) | 1.29 (0.94-1.75) |
| Ischemic Heart Disease | 859 | 10.0 | 1.18 (0.94-1.49) | 1.06 (0.88-1.29) | 1.00 | 1.13 (0.94-1.36) | 1.20 (0.95-1.53) |
| Stroke | 632 | 7.4 | 1.16 (0.88-1.52) | 0.99 (0.79-1.23) | 1.00 | 1.07 (0.87-1.33) | 1.39 (1.06-1.83)* |
| Cardiomyopathy | 89 | 1.0 | --- | --- | --- | --- | --- |
| Cardiac Arrest | 88 | 1.0 | --- | --- | --- | --- | --- |
| Hypertensive Heart Disease | 130 | 1.5 | 1.45 (0.81-2.58) | 1.34 (0.81-2.20) | 1.00 | 1.13 (0.67-1.89) | 1.72 (0.95-3.09) |
| Hypertension | 106 | 1.2 | 2.21 (1.09-4.46)* | 2.03 (1.11-3.72)* | 1.00 | 2.05 (1.13-3.71)* | 2.46 (1.22-4.97)* |
| Respiratory disease | 615 | 7.2 | 1.23 (0.92-1.65) | 1.26 (1.00-1.58) | 1.00 | 1.14 (0.91-1.43) | 1.62 (1.25-2.11)* |
| Pneumonia | 213 | 2.5 | 0.87 (0.49-1.52) | 1.45 (0.98-2.15) | 1.00 | 1.45 (0.98-2.13) | 2.08 (1.32-3.26)* |
| All others | 2,089 | 24.3 | 1.13 (0.97-1.31) | 1.03 (0.91-1.16) | 1.00 | 0.97 (0.86-1.10) | 1.33 (1.15-1.55)* |
| Infectious/Parasitic Disease | 144 | 1.7 | 1.59 (0.94-2.71) | 0.93 (0.58-1.51) | 1.00 | 1.04 (0.66-1.66) | 1.90 (1.11-3.26)* |
| Diabetes | 312 | 3.6 | 1.24 (0.84-1.84) | 1.22 (0.87-1.69) | 1.00 | 1.15 (0.83-1.59) | 1.57 (1.09-2.28)* |
| Mental/Behavioral Disease | 120 | 1.4 | 0.92 (0.46-1.83) | 1.33 (0.83-2.11) | 1.00 | 0.93 (0.56-1.54) | 0.90 (0.44-1.86) |
| Alzheimer's Disease | 155 | 1.8 | 0.93 (0.34-2.53) | 0.98 (0.48-2.02) | 1.00 | 1.36 (0.72-2.59) | 1.70 (0.73-3.97) |
| Parkinson's Disease | 64 | 0.7 | --- | --- | --- | --- | --- |
| Liver Disease | 122 | 1.4 | 1.55 (0.83-2.88) | 1.20 (0.71-2.04) | 1.00 | 1.29 (0.77-2.14) | 1.97 (1.09-3.54)* |
| Kidney Disease | 106 | 1.2 | 0.71 (0.34-1.45) | 0.73 (0.42-1.27) | 1.00 | 0.92 (0.55-1.53) | 1.36 (0.74-2.49) |
| Accidents | 155 | 1.8 | 0.74 (0.39-1.40) | 1.10 (0.73-1.66) | 1.00 | 0.86 (0.55-1.35) | 1.41 (0.82-2.44) |
Abbreviation: CI, Confidence Intervals; HR, Hazard Ratio.
HR (95% CI) which not includes 1.00
Hazard ratios were calculated with age as the time metric, adjusted for 5-year age groups at cohort entry, sex, ethnicity, education, marital status, history of hypertension or diabetes at enrollment, alcohol consumption, energy intake, body mass index, physical activity (METs per week for moderate activity, vigorous work and strenuous sports), hours spent daily watching television, and smoking history by inclusion of the following variables: [smoking status, average number of cigarettes, average number of cigarettes squared, number of years smoked (time dependent), number of years since quitting (time dependent), and interactions between ethnicity and the smoking variables].
The test of heterogeneity across causes of death was performed using competing risk techniques, where each cause was a different event. A Wald test was used to compare the parameters between causes. P for heterogeneity (degrees of freedom = 12) across malignant neoplasms, cardiovascular disease, respiratory disease, and all others was <0.01. P for heterogeneity (degrees of freedom = 32) across specific cardiovascular disease was 0.72. P for heterogeneity (degrees of freedom = 60) across cause-specific disease within ‘All others’ was 0.54.
Hazard ratios are given only for conditions with 100 cases or more.