| Men (n = 1,053) |  | Women (n = 1,574) |  | Postmenopausal Women (n = 1,330) |  | |||
---|---|---|---|---|---|---|---|---|---|
 | Educational attainment | ||||||||
 | Low | High | P value | Low | High | P value | Low | High | P value |
 | (n = 402) | (n = 651) |  | (n = 587) | (n = 987) |  | (n = 518) | (n = 812) |  |
Demographic characteristics | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Age group in years | Â | Â | <0.001 | Â | Â | <0.001 | Â | Â | <0.001 |
45-54 | 19.7 | 42.9 | Â | 17.6 | 44.5 | Â | 12.2 | 35.3 | Â |
55-64 | 23.9 | 32.1 | Â | 24.2 | 33.2 | Â | 25.9 | 38.4 | Â |
65-74 | 37.8 | 20.7 | Â | 35.8 | 15.8 | Â | 37.8 | 18.6 | Â |
75+ | 18.7 | 4.3 | Â | 22.5 | 6.5 | Â | 24.1 | 7.6 | Â |
% African American | 36.1 | 19.7 | <0.001 | 43.6 | 30.6 | <0.001 | 42.9 | 28.7 | <0.001 |
Lifestyle/clinical characteristics | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Current Smokers | 32.1 | 24.9 | 0.011 | 13.3 | 17.9 | 0.016 | 13.3 | 18.4 | 0.016 |
% Current alcohol use | 20.4 | 34.1 | <0.001 | 6.6 | 17.9 | <0.001 | 6.2 | 17.2 | <0.001 |
Mean BMI kg/m2 (SD) | 27.6(5.0) | 28.5(4.8) | 0.004 | 30.2(6.7) | 29.1(6.4) | 0.001 | 30.0(6.5) | 29.0(6.3) | 0.005 |
% Knee injury | 15.9 | 18.4 | 0.297 | 15.7 | 15.6 | 0.970 | 16.4 | 16.3 | 0.941 |
Occupation characteristics | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Physically demanding occupationa | 83.3 | 43.0 | <0.001 | 82.8 | 38.0 | <0.001 | 82.2 | 37.4 | <0.001 |
Mean occupational physical activities score (SD)b | 10.7(2.6) | 10.0(2.7) | <0.001 | 8.7(3.1) | 8.8(3.0) | 0.505 | 8.6(3.0) | 8.7(3.1) | 0.630 |
HRT use characteristics | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Current HRT use | N/A | N/A | N/A | N/A | N/A | N/A | 13.9 | 30.8 | <0.001 |
Radiographic OA | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Radiographic knee OA | 32.8 | 22.9 | <0.001 | 41.9 | 23.9 | <0.001 | 41.9 | 24.9 | <0.001 |
% Bilateral radiographic knee OA | 19.9 | 12.1 | 0.001 | 28.7 | 12.7 | <0.001 | 29.2 | 13.7 | <0.001 |
Symptomatic OA | Â | Â | Â | Â | Â | Â | Â | Â | Â |
% Symptomatic knee OA | 20.2 | 11.1 | <0.001 | 27.0 | 12.1 | <0.001 | 27.1 | 13.5 | <0.001 |
% Symptomatic bilateral knee OA | 5.9 | 4.0 | 0.189 | 13.4 | 4.7 | <0.001 | 13.1 | 5.0 | <0.001 |