Table 1.
Baseline characteristics of patients of the BSRBR-AS cohort according to radiographic status
| Variables | Level | nr-axSpA (n = 418) | r-axSpA (n = 727) | P-value |
|---|---|---|---|---|
| Age, mean (s.d.), years | 39.7 (12.3) | 46.1 (13.4) | <0.001 | |
| Sex, n (%) | Male | 239 (57) | 529 (73) | <0.001 |
| Symptom duration, mean (s.d.), years | 11.3 (10.9) | 16.7 (12.9) | <0.001 | |
| Diagnostic delay, median (IQR), years | 3.0 (1.0–10.0) | 3.0 (0.0–11.0) | 0.83 | |
| HLA-B27 (missing = 325) | 227 (73) | 387 (76) | 0.40 | |
| Inflammatory back pain, n (%) | 405 (97) | 697 (97) | 0.40 | |
| Uveitis, n (%) | 92 (22) | 205 (30) | 0.003 | |
| Crohn’s/colitis, n (%) | 55 (13) | 113 (17) | 0.11 | |
| Psoriasis, n (%) | 79 (19) | 115 (17) | 0.43 | |
| BMI, mean (s.d.) | 27.5 (5.6) | 28.2 (5.8) | 0.10 | |
| Comorbidity count, mean (s.d.) | 0.6 (0.9) | 0.7 (1.0) | 0.016 | |
| Smoking status, n (%) | Never smoked | 148 (43) | 218 (38) | 0.040 |
| Ex-smoker | 96 (28) | 207 (36) | ||
| Current smoker | 100 (29) | 154 (27) | ||
| CRP, median (IQR), mg/dL | 0.5 (0.1–1.3) | 0.9 (0.3–2.5) | <0.001 | |
| BASDAI, median (IQR) | 6.7 (5.3–7.8) | 6.5 (5.0–7.7) | 0.12 | |
| BASFI, median (IQR) | 5.9 (4.2–7.8) | 6.5 (4.4–8.3) | 0.043 | |
| BAS-G, mean (s.d.) | 7.0 (2.0) | 6.8 (2.0) | 0.056 | |
| ASDAS-CRP, mean (s.d.) | 2.8 (0.8) | 2.8 (0.9) | 0.32 | |
| ASQOL, median (IQR) | 13.0 (9.0–16.0) | 13.0 (9.0–15.5) | 0.29 | |
| Concomitant NSAID use, n (%) | 311 (75) | 560 (77) | 0.43 | |
| Biologic (to start), n (%) | Adalimumab | 238 (57) | 436 (60) | 0.20 |
| Etanercept | 131 (31) | 220 (30) | ||
| Certolizumab | 35 (8) | 47 (6) | ||
| Golimumab | 5 (1) | 12 (2) | ||
| Secukinumab | 7 (2) | 10 (1) | ||
| Infliximab | 2 (<1) | 2 (<1) |
ASQOL: Ankylosing Spondylitis Quality of Life questionnaire.