Sample characteristics of patients with rheumatoid arthritis and controls.
| Characteristics | Cases, n=239 | Controls, n=127 |
|---|---|---|
| Related individuals, n | 69 | 83 |
| Unrelated individuals, n | 170 | 44 |
| Mean age, yrs (± SD) | 39.1 ± 13.0 | 41.2 ± 12.0 |
| Female, % | 63 | 54 |
| Rheumatoid factor seropositive, % | 100 | 0 |