Baseline patient characteristics
| Baseline characteristic, mean (SD), unless otherwise stated | MRI set n=136 | ||
| r-axSpA n=76 | nr-axSpA n=60 | All patients n=136 | |
| Age, years | 40.4 (11.6) | 37.3 (13.0) | 39.1 (12.3) |
| Sex, male, n (%) | 52 (68.4) | 31 (51.7) | 83 (61.0) |
| HLA-B27, positive, n (%) | 59 (77.6) | 46 (76.7) | 105 (77.2) |
| BMI, kg/m2 | 27.0 (5.2)* | 26.8 (6.0)† | 26.9 (5.5)‡ |
| Symptom duration, years, median (min, max) | 10.3 (0.3, 50.9) | 5.9 (0.3, 39.6) | 8.1 (0.3, 50.9) |
| ASDAS | 4.0 (0.9) | 3.8 (0.9)† | 3.9 (0.9)§ |
| BASDAI | 6.8 (1.5) | 6.6 (1.5) | 6.7 (1.5) |
| CRP, mg/L, | 21.2 (27.5) | 16.2 (17.0) | 19.0 (23.5) |
| >15 mg/L, n (%) | 32 (42.1) | 23 (38.3) | 55 (40.4) |
| ASspiMRI-a Berlin score | 6.4 (8.1) | 4.5 (8.5)¶ | 5.6 (8.3)** |
| SPARCC MRI SIJ score | 9.5 (14.9)* | 7.8 (12.4)†† | 8.8 (13.8)‡‡ |
| MRI, positive, n (%) | 76 (100.0) | 37 (61.7) | 113 (83.1) |
MRI set (n=136); includes patients evaluable for MRI and who have ≥1 pre-CZP and ≥1 post-CZP MRI assessment.
*n=75.
†n=59.
‡n=134.
§n=135.
¶n=56.
**n=132.
††n=55.
‡‡n=130.
ASDAS, Axial Spondyloarthritis Disease Activity Score; ASspiMRI-a, Ankylosing Spondylitis spine MRI score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; BMI, body mass index; CRP, C reactive protein; HLA-B27, human leucocyte antigen B27; MRI+, positive MRI; nr-axSpA, non-radiographic axial spondyloarthritis; r-axSpA, radiographic axial spondyloarthritis; SIJ, sarcoiliac joint; SPARCC, Spondyloarthritis Research Consortium of Canada.