Characteristics of and disease activity in patients with axSpA at the time of tumor necrosis factor (TNF) initiation. Except where indicated otherwise, values are mean (SD).
| Characteristic | n | Private Practices, n = 363 | Academic Centers, n = 100 | p |
|---|---|---|---|---|
| Male sex, % | 463 | 62.3 | 62.0 | 1.00 |
| Age, yrs | 463 | 40.7 ± 12.1 | 39.4 ± 11.1 | 0.34 |
| Disease duration, yrs | 456 | 12.7 ± 10.0 | 13.7 ± 12.0 | 0.82 |
| Nr-axSpA, % | 397 | 18.7 | 30.4 | 0.02 |
| HLA-B27+, % | 408 | 80.5 | 72.5 | 0.13 |
| BASDAI | 463 | 5.3 ± 2.1 | 5.9 ± 2.0 | 0.01 |
| BASDAI ≥ 4, % | 463 | 73.8 | 77.0 | 0.60 |
| ASDAS-CRP | 433 | 3.4 ± 1.0 | 3.4 ± 0.9 | 0.68 |
| ASDAS ≥ 2.1, % | 433 | 89.6 | 92.8 | 0.44 |
| BASFI | 464 | 3.9 ± 2.4 | 4.5 ± 2.5 | 0.03 |
| BASMI | 406 | 2.4 ± 2.1 | 1.8 ± 1.9 | 0.01 |
| Sacroiliitis on MRI, % | 463 | 34.4 | 56.0 | < 0.001 |
| Ever peripheral arthritis, % | 455 | 34.3 | 40.4 | 0.29 |
| Elevated CRP, % | 434 | 53.7 | 51.5 | 0.73 |
| CRP, mg/l | 436 | 17.2 ± 21.7 | 13.1 ± 16.5 | 0.01 |
| ESR, mm/h | 439 | 22.2 ± 20.4 | 18.6 ± 19.2 | 0.10 |
| SF-36 MCS | 386 | 43.6 ± 11.7 | 39.8 ± 9.8 | 0.004 |
| SF-36 PCS | 386 | 34.7 ± 9.7 | 33.2 ± 8.5 | 0.16 |
| EQ-5D | 452 | 54.9 ± 22.2 | 52.4 ± 22.4 | 0.27 |
| No. exercise sessions/week | 415 | 2.0 ± 2.0 | 2.0 ± 2.5 | 0.26 |
| Smoker, % | 460 | 60.6 | 64.0 | 0.56 |
| Ever NSAID, % | 463 | 100 | 100 | — |
| Ever DMARD, % | 463 | 40.8 | 48.0 | 0.21 |
| Anti-TNF type, IV/SC, % | 463 | 23.4/76.6 | 30.0/70.0 | 0.19 |
AxSpA: axial spondyloarthritis; nr-axSpA: nonradiographic axSpA; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; ASDAS-CRP: Ankylosing Spondylitis Disease Activity Score using C-reactive protein (CRP) levels; BASFI: Bath Ankylosing Spondylitis Functional Index; BASMI: Bath Ankylosing Spondylitis Metrology Index; sacroiliitis on MRI: inflammation of the sacroiliac joint appearing on magnetic resonance imaging; ESR: erythrocyte sedimentation rate; SF-36: Medical Outcomes Study Short Form-36 health survey; PCS: physical component score; MCS: mental component score; EQ-5D: EuroQol 5-domain; NSAID: nonsteroidal antiinflammatory drug; DMARD: disease-modifying antirheumatic drug; IV: intravenous; SC: subcutaneous.