Table 2.
Cox proportional hazards models: relationship between sedentary time and all-cause, CVD, CHD, and cancer mortality
| Baseline sedentary time | p-value for trenda | ||||
|---|---|---|---|---|---|
| ≤4 hours | >4–8 hours | >8–11 hours | ≥11 hours | ||
| N | 13,134 | 35,668 | 23,245 | 20,187 | |
| Person-year of follow-up | 158,703.06 | 436,043.51 | 284,539.86 | 246,139.09 | |
| All-cause mortality | |||||
| Number of deaths | 1,855 | 4,993 | 3,395 | 3,073 | |
| Age-adjusted hazard ratio | 1.00 | 0.95 (0.90, 1.01) | 1.06 (1.00, 1.12) | 1.26 (1.19, 1.34) | <0.0001 |
| Age, race, physical activities, and physical function score adjusted | 1.00 | 0.99 (0.94, 1.05) | 1.05 (0.99, 1.11) | 1.12 (1.06, 1.19) | <0.0001 |
| Multivariate hazard ratiob | 1.00 | 1.03 (0.97, 1.10) | 1.07 (0.99, 1.14) | 1.12 (1.05, 1.21) | 0.0006 |
| CVD death | |||||
| Number of deaths | 551 | 1,445 | 987 | 895 | |
| Age-adjusted hazard ratio | 1.00 | 0.93 (0.84, 1.03) | 1.05 (0.94, 1.16) | 1.30 (1.17, 1.44) | <0.0001 |
| Age, race, physical activities, and physical function score adjusted | 1.00 | 1.01 (0.92, 1.12) | 1.06 (0.95, 1.18) | 1.14 (1.02, 1.28) | 0.0049 |
| Multivariate hazard ratiob | 1.00 | 1.04 (0.92, 1.17) | 1.06 (0.93, 1.20) | 1.13 (0.99, 1.29) | 0.0446 |
| CHD death | |||||
| Number of deaths | 222 | 657 | 459 | 418 | |
| Age-adjusted hazard ratio | 1.00 | 1.05 (0.90, 1.22) | 1.21 (1.03, 1.42) | 1.50 (1.27, 1.77) | <0.0001 |
| Age, race, physical activities, and physical function score adjusted | 1.00 | 1.17 (1.00, 1.37) | 1.24 (1.05, 1.46) | 1.32 (1.11, 1.57) | 0.0019 |
| Multivariate hazard ratiob | 1.00 | 1.18 (0.98, 1.42) | 1.19 (0.98, 1.45) | 1.27 (1.04, 1.55) | 0.0421 |
| Cancer death | |||||
| Number of deaths | 605 | 1,771 | 1,280 | 1,103 | |
| Age-adjusted hazard ratio | 1.00 | 1.05 (0.95, 1.15) | 1.21 (1.10, 1.33) | 1.31 (1.19, 1.45) | <0.0001 |
| Age, race, physical activities, and physical function score adjusted | 1.00 | 1.04 (0.94, 1.14) | 1.18 (1.07, 1.31) | 1.22 (1.10, 1.36) | <0.0001 |
| Multivariate hazard ratiob | 1.00 | 1.09 (0.98, 1.22) | 1.21 (1.07, 1.35) | 1.21 (1.07, 1.37) | 0.0002 |
Note: Values within parentheses are 95% CIs.
p-value for linear trend was obtained by using the computed value of total sedentary time as continuous variable in the model
Model adjusted for age, race/ethnicity, education, marital status, BMI, self-rated health status, smoking, alcohol consumption, number of chronic diseases, hormone use, depressed mood, living alone, number of falls in the past 12 months, activity of daily living disability, history of CHD and/or CHF, physical functioning score, physical activity level, history of stroke, treated diabetes, hypertensive, arthritis, cancer, chronic obstructive pulmonary disease, and history of hip fracture over age 55; CHD, coronary heart disease
CHF, congestive heart failure; CVD, cardiovascular disease