Characteristics of patients with antinuclear antibody tests, overall and by number of tests
| Characteristic | No. (%) of patients* | ||
|---|---|---|---|
| Total n = 437 966 | 1 test n = 346 282 | ≥ 2 tests n = 91 684 | |
| Age, yr, mean ± SD | 52.4 ± 16.3 | 51.9 ± 16.5 | 54.5 ± 15.3 |
| Female sex | 294 130 (67.2) | 226 363 (65.4) | 67 767 (73.9) |
| Connective tissue disease | 24 037 (5.5) | 13 610 (3.9) | 10 427 (11.4) |
| Hospital admission in 2 yr preceding index test | 22 600 (5.2) | 17 701 (5.1) | 4899 (5.3) |
| Urban residence | 378 822 (86.5) | 299 480 (86.5) | 79 342 (86.5) |
Note: SD = standard deviation.
↵* Except where noted otherwise.