Relationship between baseline BMD and 2-year syndesmophyte formation based on agreement between both readers
| Independent variables | New radiographic syndesmophyte formation according to both reader 1 and reader 2 | |
|---|---|---|
| Univariable analysis—adjOR (95% CI) | Multivariable analysis—adjOR (95%) | |
| BMD (g/cm2) | 0.12 (0.00, 9.94) | 0.56 (0.01, 44.45) |
| Age (years) | 1.05 (0.99, 1.12) | 1.03 (0.95, 1.11) |
| Gender (male) | 1.60 (0.31, 8.30) | 0.82 (0.10, 6.85) |
| Disease duration (years) | 1.06 (1.01, 1.11)* | 1.05 (0.97, 1.14) |
| ASDAS | 1.62 (0.72, 3.65) | 1.79 (0.66, 4.86) |
| HLA-B27 | 0.27 (0.05, 1.38) | 0.13 (0.02, 0.89) |
| Treatment with NSAIDs | 0.79 (0.16, 3.85) | 0.41 (0.07, 2.47) |
| Treatment with infliximab | 1.81 (0.22, 14.98) | 1.82 (0.22, 15.31) |
| Presence of MRI VCI at baseline† | 3.63 (0.87, 15.31) | 4.00 (0.99, 16.13) |
| Presence of MRI VCFD at baseline† | 0.55 (0.13, 2.29) | 0.69 (0.16, 3.01) |
| Presence of syndesmophytes at baseline†,‡ | 8.51 (1.06, 68.13)* | 20.20 (0.96, 424.63) |
adjOR, Adjusted OR; ASDAS, Ankylosing Spondylitis Disease Activity Score; BMD, Bone mineral density; CI, Confidence Interval; GEE, Generalised estimated equations; NSAIDs, Nonsteroidal anti-inflammatory drugs; VCFD, Vertebral corner fat deposition; VCI, Vertebral corner inflammation.
†Radiographic and MRI case definitions aiming at specificity were used (absolute agreement of the readers).
‡Syndesmophytes anywhere in the spine defined as a patient with at least one vertebral corner that received a modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) of ≥2, according to the absolute agreement of readers. *p<0.05.