Table 1.
Study characteristics by prediagnosis sleep duration among colorectal cancer patients in the NIH-AARP Diet and Health Study (1995–1996).
| Sleep duration | p value | ||||
|---|---|---|---|---|---|
| <5 hr (N = 150) | 5–6 hr (N = 1519) | 7–8 hr (N = 2984) | 9+ hr (N = 216) | ||
| Colorectal cancer diagnosis, % | .40 a | ||||
| Colon | 74.0 | 71.8 | 74.1 | 73.1 | |
| Rectum | 26.0 | 28.2 | 25.9 | 26.9 | |
| Tumor summary stage, % | .65 a | ||||
| Localized | 31.3 | 27.0 | 27.8 | 28.7 | |
| Regional | 26.7 | 29.2 | 26.3 | 28.2 | |
| Metastatic | 8.0 | 10.5 | 10.7 | 8.8 | |
| Unknown | 34.0 | 33.3 | 35.2 | 34.3 | |
| Tumor grade at diagnosis, % | .68 a | ||||
| Well differentiated | 14.0 | 11.1 | 10.8 | 11.1 | |
| Moderately differentiated | 55.3 | 57.9 | 57.9 | 59.3 | |
| Poorly differentiated | 14.7 | 13.8 | 15.7 | 13.9 | |
| Undifferentiated | 0.0 | 0.5 | 0.8 | 0.5 | |
| Unknown | 16.0 | 16.7 | 14.8 | 15.3 | |
| First course of cancer treatment, % | |||||
| Chemotherapy | 31.8 | 32.1 | 34.2 | 29.5 | .37 a |
| Surgery | 72.5 | 80.3 | 79.7 | 81.8 | .22 a |
| Radiation | 11.1 | 11.8 | 10.9 | 6.5 | .20 a |
| Age at cancer diagnosis, years, mean (SD) | 67.4 (5.5) | 68.3 (5.6) | 68.6 (5.4) | 68.9 (5.2) | .03 b |
| Age at sleep assessment, years, mean (SD) | 63.9 (4.5) | 64.4 (4.9) | 64.7 (4.7) | 65.1 (4.4) | .04 b |
| Women, % | 40.0 | 36.5 | 32.3 | 32.4 | .01 a |
| College or graduate degree, % | 18.9 | 33.5 | 40.5 | 33.2 | <.0001 a |
| Non-Hispanic white, % | 89.3 | 92.2 | 95.5 | 97.2 | <.0001 a |
| Napping, % | <.0001 a | ||||
| None | 38.7 | 41.5 | 47.0 | 45.4 | |
| <1 hr/day | 40.0 | 44.0 | 43.4 | 35.7 | |
| 1+ hr/day | 21.3 | 14.5 | 9.6 | 19.0 | |
| Smoking at baseline, % | .17 a | ||||
| Current smoker | 15.8 | 12.3 | 10.9 | 10.2 | |
| Former smoker | 51.8 | 55.5 | 57.3 | 63.4 | |
| Never smoke | 32.4 | 32.2 | 31.8 | 26.3 | |
| BMI at baseline, kg/m2, mean (SD) | 29.1 (6.1) | 27.8 (5.2) | 27.1 (4.8) | 27.8 (5.4) | <.0001 b |
| Watching TV at baseline, 5+ hours/day, % | 30.8 | 25.0 | 23.8 | 25.6 | <.0001 a |
| Baseline MVPA, >4 hr/week, % | 37.8 | 45.1 | 47.1 | 47.4 | 0.0002 a |
| Total drinks of alcohol at baseline, mean (SD) | 1.1 (3.9) | 1.1 (3.2) | 1.2 (3.0) | 2.2 (4.6) | <.0001 c |
| Red meat intake at baseline, g/kcal, mean (SD) | 35.8 (23.1) | 37.2 (23.0) | 36.4 (21.4) | 37.2 (24.0) | .86 c |
| Self-reported diseases at baseline, % | |||||
| Diabetes | 18.0 | 13.5 | 10.3 | 13.9 | .0005 a |
| Heart disease | 18.7 | 16.0 | 15.9 | 18.5 | .61 |
| Stroke | 2.0 | 2.7 | 2.6 | 3.7 | .75 |
| Self-reported health at baseline, poor or fair, % | 26.7 | 13.8 | 10.9 | 18.5 | <.0001 a |
a p value was derived from Chi-square test.
b p value was derived from one-way ANOVA.
c p value was derived from Kruskal–Wallis test.
Abbreviation: BMI, bodymass index; hr, hour; MVPA, moderate-to-vigorous physical activity; SD, standard deviation.