Demographic data, clinical characteristics, and individual risk factors for LTBI.
| Characteristic | RA | AS |
|---|---|---|
| n | 82 | 58 |
| Age, mean, yrs (SD) | 55.4 (11.2) | 39.5 (11.2) |
| Sex (F/M) | 73/9 | 22/36 |
| BCG vaccinated, % | 77 | 95 |
| Disease related factors | ||
| Disease duration, yrs, mean (SD) | 13 ± 9 | 12 ± 8 |
| RF-positive, % | 65 | NA |
| HLA-B27-positive, % | NA | 78 |
| DAS28 (mean ± SD) | 4.8 ± 1.3 | NA |
| BASDAI (mean ± SD) | NA | 27 ± 14 |
| Treatment at recruitment | ||
| Prednisolone, % | 60 | 5 |
| Mean prednisolone at recruitment, mg/day | 4.8 + 5.2 | 0.3 ± 1.3 |
| Mean duration of prednisolone, yrs | 5.0 ± 5.4 | 2.4 ± 15.9 |
| DMARD only, % | 70 | 60 |
| DMARD and TNF antagonist, % | 7 | 2 |
| TNF antagonist only, % | 10 | 17 |
| DMARD and TNF-naive, % | 13 | 21 |
| New treatment with TNF antagonists, % | 21 | 22 |
| Risk factors for LTBI, % | ||
| History of TB infection, % | 4 | 2 |
| Chest radiograph suggestive of TB, % | 8 | 6 |
| History of TB in close relatives, % | 15 | 11 |
LTBI: latent tuberculosis infection; RA: rheumatoid arthritis; AS: ankylosing spondylitis; BCG: bacillus Calmette-Guerin; SD: standard deviation; RF: rheumatoid factor; DAS28: Disease Activity Score 28-joint count; DMARD: disease-modifying antirheumatic drugs; TNF: tumor necrosis factor; NA: not applicable.