Table 3 Association of various factors with the risk of knee osteoarthritis in this study
Variables | Non-OA(n) | OA(n) | Prevalence rate (%) | P value |
|---|---|---|---|---|
Sex |  |  |  |  < 0.001 |
 Male | 1824 | 126 | 6.5 |  |
 Female | 1696 | 278 | 14.1 |  |
Age group |  |  |  |  < 0.001 |
 < 55 years | 1333 | 60 | 4.3 |  |
 55–64 years | 1168 | 176 | 13.1 |  |
 65–74 years | 887 | 142 | 13.8 |  |
 ≥ 75 years | 113 | 26 | 19.1 |  |
Education |  |  |  | < 0.001 |
 Illiterate | 283 | 66 | 18.9 |  |
 Primary level | 968 | 134 | 12.2 |  |
 Elementary level | 1840 | 149 | 7.0 |  |
 High school | 385 | 55 | 12.5 |  |
 ≥ College | 40 | 0 | 0.0 |  |
Smoking |  |  |  | < 0.001 |
 Never smoking | 2467 | 337 | 12.0 |  |
 Ex-smoker | 146 | 11 | 7.0 |  |
 Current smoker | 899 | 56 | 5.9 |  |
Drinking |  |  |  | < 0.001 |
 Never drinking | 2593 | 334 | 11.4 |  |
 Ex-drinker | 71 | 7 | 9.0 |  |
 Current drinker | 848 | 62 | 6.8 |  |
BMI group |  |  |  | < 0.001 |
 Normal | 1482 | 120 | 7.5 |  |
 Over weight | 1468 | 181 | 11.0 |  |
 Obesity | 529 | 98 | 15.6 |  |
Sleep situation |  |  |  | < 0.001 |
 Satisfy | 2846 | 261 | 8.4 |  |
 Not bad | 409 | 85 | 17.2 |  |
 Insufficient | 244 | 55 | 18.4 |  |
Often walk |  |  |  | < 0.001 |
 Yes | 942 | 165 | 14.9 |  |
 No | 2509 | 239 | 8.7 |  |