Table 1.
Demographic data.
| Variable | Patients with Knee OA and Underwent TKR (n = 10,021) | Controls (n = 30,063) | p Value | ||
|---|---|---|---|---|---|
| n | % | n | % | ||
| Age, mean (SD) | 72.99(8.52) | 73.12(8.67) | 0.1940 | ||
| Sex | 1.0000 | ||||
| Males | 2758 | 27.52 | 8274 | 27.52 | |
| Females | 7263 | 72.48 | 21,789 | 72.48 | |
| Income † | 0.5919 | ||||
| NT$1–15,841 | 2051 | 20.47 | 6031 | 20.06 | |
| NT$15,841–25,000 | 5148 | 51.37 | 15,444 | 51.37 | |
| NT$ > 25,001 | 2822 | 28.16 | 8588 | 28.57 | |
| Area | <0.0001 | ||||
| Northern | 4038 | 40.30 | 12,087 | 40.21 | |
| Central | 2524 | 25.19 | 7724 | 25.69 | |
| Southern | 3115 | 31.08 | 9601 | 31.94 | |
| Eastern | 344 | 3.43 | 651 | 2.17 | |
| Urbanization ‡ | 0.8014 | ||||
| Urb-1 | 2140 | 21.36 | 6379 | 21.22 | |
| Urb-2 | 2417 | 24.12 | 7414 | 24.66 | |
| Urb-3 | 1680 | 16.76 | 5078 | 16.89 | |
| Urb-4 | 1826 | 18.22 | 5420 | 18.03 | |
| Urb-5 | 1958 | 19.54 | 5772 | 19.20 | |
| Hypertension | 7953 | 79.36 | 23,859 | 79.36 | 1.0000 |
| Hyperlipidemia | 6024 | 60.11 | 18,072 | 60.11 | 1.0000 |
| Diabetes | 4347 | 43.38 | 13,041 | 43.38 | 1.0000 |
| Coronary heart disease | 3364 | 33.57 | 10,092 | 33.57 | 1.0000 |
† In 2024, the average exchange rate was US$1 ≈ NT$32. ‡ Urb-1 = most urbanized, Urb-5 = least urbanized. SD: standard deviation. NT$ = Taiwanese new dollar.