Table 1.
Descriptive characteristics of the sample by knee pain status among nonfrail participants at baseline
| Characteristics | All (N = 3,053) | No KP (N = 1,600, 52%) | Unilateral KP (N = 822, 27%) | Bilateral KP (N = 631, 21%) | P |
|---|---|---|---|---|---|
| Age, mean ± SD, y | 59.9 ± 8.8 | 61.1 ± 8.9 | 59.7± 8.9 | 59.0 ± 8.5 | <0.001 |
| BMI, mean ± SD, kg/m2 | 28.3 ± 4.6 | 27.6 ± 4.5 | 28.6 ± 4.5 | 28.8 ± 4.7 | <0.001 |
| Female, No. (%) | 1,672 (55) | 897 (54) | 420 (25) | 355 (21) | 0.047 |
| Caucasians or white, No. (%) | 2,564 (84) | 1,424 (55) | 668 (26) | 472 (18) | <0.001 |
| High school or more, No. (%) | 2,673 (87) | 1,423 (53) | 716 (27) | 534 (20) | 0.019 |
| Married, No. (%) | 2,191 (72) | 1,183 (54) | 598 (27) | 410 (19) | <0.001 |
| Current or former smoker, No. (%) | 1,378 (45) | 700 (51) | 384 (28) | 294 (21) | 0.27 |
| Comorbidity >1, No. (%) | 427 (15) | 192 (45) | 132 (31) | 103 (24) | 0.002 |
| PASE, mean ± SD | 157.5 ± 83.5 | 156.7 ± 76.5 | 159.0 ± 85.3 | 156.7 ± 88.6 | 0.32 |
BMI = body mass index; KP = knee pain; PASE = physical activity scale for the elderly.