Table 2. Multivariable-adjusted associations of baseline sleep duration with breast cancer recurrence, mortality, and all-cause mortality among 3047 breast cancer survivors in the Women's Healthy Eating and Living Study.
| Breast cancer recurrence (n = 568 events) HR (95% CI) | Breast cancer mortality (n = 446 events) HR (95% CI) | All-cause mortality (n = 649 events) HR (95% CI) | |
|---|---|---|---|
| Sleep category | |||
| Short sleep (≤6 h/night) | 0.93 (0.77, 1.12) | 0.83 (0.67, 1.04) | 0.95 (0.80, 1.13) |
| Middle sleep (7–8 h/night) | 1.00 (ref) | 1.00 (ref) | 1.00 (ref) |
| Long sleep (≥9 h/night) | 1.48 (1.01, 2.00) | 1.52 (1.09, 2.13) | 1.43 (1.07, 1.92) |
Bold values indicate statistically significant associations
Models also controlled for age, stage, grade, body mass index (kg/m2), number of co-morbidities, race/ethnicity, intervention group, and study site
CI confidence interval, HR Hazard ratio