Table 1.
Baseline Characteristics Stratified by Total Sedentary Time*
| Quartile 1 | Quartile 2 | Quartile 3 | Quartile 4 | P value | |
|---|---|---|---|---|---|
| N=670 | N=668 | N=667 | N=670 | ||
| Age, y, mean (SD) | 76.19 (6.14) | 77.95 (6.64) | 78.40 (6.51) | 80.38 (6.68) | <0.001 |
| Race and ethnicity, n (%) | <0.001 | ||||
| White | 269 (40.1) | 325 (48.7) | 331 (49.6) | 422 (63.0) | |
| Black | 265 (39.6) | 233 (34.9) | 253 (37.9) | 193 (28.8) | |
| Hispanic | 136 (20.3) | 110 (16.5) | 83 (12.4) | 55 (8.2) | |
| Education, n (%) | 0.04 | ||||
| College graduate or more | 309 (46.1) | 315 (47.6) | 265 (40.2) | 281 (42.0) | |
| Some college | 233 (34.8) | 222 (33.5) | 265 (40.2) | 271 (40.5) | |
| High school or equivalent | 128 (19.1) | 125 (18.9) | 129 (19.6) | 117 (17.5) | |
| Ever smoker, n (%) | 275 (41.5) | 277 (41.7) | 304 (46.2) | 322 (48.4) | 0.024 |
| Body mass index, kg/m2, mean (SD) | 26.30 (4.99) | 27.54 (5.33) | 28.39 (5.35) | 30.06 (6.00) | <0.001 |
| Hypertension, n (%) | 423 (63.1) | 468 (70.1) | 499 (74.8) | 529 (79.0) | <0.001 |
| Diabetes, n (%) | 89 (13.3) | 137 (20.5) | 137 (20.5) | 168 (25.1) | <0.001 |
| Stroke, n (%) | 23 (3.4) | 21 (3.1) | 45 (6.7) | 51 (7.6) | <0.001 |
| Heart disease, n (%) † | 27 (4.0) | 53 (7.9) | 48 (7.2) | 66 (9.9) | 0.001 |
| Comorbidity index, n (%) ‡ | <0.001 | ||||
| 0 | 210 (31.4) | 171 (25.7) | 154 (23.2) | 135 (20.3) | |
| 1 | 270 (40.4) | 277 (41.7) | 277 (41.8) | 249 (37.4) | |
| 2 | 141 (21.1) | 159 (23.9) | 166 (25.0) | 178 (26.7) | |
| 3+ | 47 (7.0) | 58 (8.7) | 66 (10.0) | 104 (15.6) | |
| Self‐rated health, n (%) | <0.001 | ||||
| Excellent | 112 (16.8) | 79 (11.9) | 54 (8.1) | 39 (5.8) | |
| Very good | 318 (47.7) | 267 (40.1) | 306 (45.9) | 271 (40.6) | |
| Good | 212 (31.8) | 269 (40.4) | 251 (37.7) | 272 (40.7) | |
| Fair/poor | 25 (3.7) | 51 (7.7) | 55 (8.3) | 86 (12.9) | |
| Physical function score, mean (SD) § | 80.91 (19.62) | 73.61 (23.25) | 69.77 (25.13) | 58.75 (27.31) | <0.001 |
| Total sedentary time, h/d, mean (SD) | 7.26 (0.81) | 8.78 (0.28) | 9.73 (0.27) | 11.03 (0.64) | <0.001 |
| Moderate‐to‐vigorous physical activity, min/d, mean (SD) | 82.86 (36.58) | 55.90 (27.09) | 41.91 (21.67) | 27.01 (17.98) | <0.001 |
Total sedentary time and time spent in moderate‐to‐vigorous physical activity are each adjusted for accelerometer wear time. Cut points for total sedentary time: quartile 1=3.25–8.27 h/d; quartile 2=8.27–9.27 h/d; quartile 3=9.27–10.22 h/d; quartile 4=10.22–13.86 h/d. Number of missing values excluded from table: education=15, smoking history=25, body mass index=169, comorbidity index=13, self‐rated health=8, physical function score=23.
Heart disease includes coronary artery disease and congestive heart failure.
The 8 chronic conditions included in the comorbidity index are cancer, osteoarthritis, depression, chronic obstructive pulmonary disease, cognitive impairment, sensory impairment, frequent falls, and incontinence.
Physical function score, dervied from part of the RAND‐36 (a 36‐item survey on health‐related quality of life), has a range of 0 to 100, where higher scores suggest better function.