Longitudinal relationship between disease activity and radiographic damage
| Model with ASDAS continuous | Model with ASDAS categorical | Model with BASDAI continuous and CRP | Model with BASDAI categorical and CRP | Model with Patient global and CRP | Model with back pain and CPR | ||
|---|---|---|---|---|---|---|---|
| Variable | Analysis in separate models ß (95% CI)* (N=174–185) | Multivariable regression 1 ß (95% CI) (N=183†) | Multivariable regression 2 ß (95% CI) (N=183†) | Multivariable regression 3 ß (95% CI) (N=184) | Multivariable regression 4 ß (95% CI) (N=184) | Multivariable regression 5 ß (95% CI) (N=184) | Multivariable regression 6 ß (95% CI) (N=184) |
| Previous mSASSS (0–72) | – | 1.03 (1.01 to 1.05) | 1.03 (1.01 to 1.05) | 1.03 (1.01 to 1.05) | 1.03 (1.01 to 1.05) | 1.03 (1.01 to 1.05) | 1.03 (1.01 to 1.05) |
| ASDAS | 0.72 (0.41 to 1.04) | 0.72 (0.41 to 1.04) | ‡ | ‡ | ‡ | ‡ | ‡ |
| ASDAS disease activity states | |||||||
| Moderate vs inactive (≥1.3 and <2.1 vs <1.3) | 0.57 (−0.56 to 1.69) | ‡ | 0.57 (−0.56 to 1.69) | ‡ | ‡ | ‡ | ‡ |
| High vs inactive (≥2.1 and ≤3.5 vs <1.3) | 0.91 (−0.17 to 1.99) | ‡ | 0.91 (−0.17 to 1.99) | ‡ | ‡ | ‡ | ‡ |
| Very high vs inactive (>3.5 vs <1.3) | 2.31 (1.11 to 3.51) | ‡ | 2.31 (1.11 to 3.51) | ‡ | ‡ | ‡ | ‡ |
| BASDAI (0–10) | 0.24 (0.09 to 0.40) | ‡ | ‡ | 0.21 (0.06 to 0.37) | ‡ | ‡ | ‡ |
| BASDAI disease activity states | |||||||
| Moderate vs inactive (≥2 and <4 vs <2) | −0.19 (−0.98 to 0.60) | ‡ | ‡ | ‡ | −0.29 (−1.09 to 0.52) | ‡ | ‡ |
| High vs inactive (≥4 and ≤6 vs <2) | 1.13 (0.30 to 1.97) | ‡ | ‡ | ‡ | 1.06 (0.21 to 1.90) | ‡ | ‡ |
| Very high vs inactive (>6 vs <2) | 1.11 (0.12 to 2.11) | ‡ | ‡ | ‡ | 0.82 (−0.19 to 1.84) | ‡ | ‡ |
| CRP (mg/L) | 0.02 (0.01 to 0.04) | ‡ | ‡ | 0.02 (0.00 to 0.04) | 0.02 (0.01 to 0.04) | 0.02 (0.00 to 0.04) | 0.02 (0.00 to 0.04) |
| ESR (mm/h) | 0.02 (−0.01 to 0.04) | ‡ | ‡ | ‡ | ‡ | ‡ | ‡ |
| Patient's global assessment (0–10) | 0.20 (0.08 to 0.32) | ‡ | ‡ | ‡ | ‡ | 0.17 (0.05 to 0.29) | ‡ |
| Pain (0–10) | 0.25 (0.12 to 0.38) | ‡ | ‡ | ‡ | ‡ | ‡ | 0.22 (0.00 to 0.04) |
| HLA-B27 (positive vs negative) | 0.47 (−0.47 to 1.41) | § | § | § | § | § | § |
| Biologics | 0.25 (−0.94 to 1.44) | § | § | § | § | § | § |
| DMARDs | 1.03 (−0.19 to 2.25) | § | § | § | § | § | § |
| NSAIDs | 0.58 (−0.10 to 1.26) | § | § | § | § | § | § |
| NSAID score (0–100) | 0.00 (−0.01 to 0.01) | § | § | § | § | § | § |
| Uveitis | −0.11 (−0.89 to 0.66) | § | § | § | § | § | § |
| Inflammatory bowel disease | 0.26 (−0.81 to 1.33) | § | § | § | § | § | § |
| Psoriasis | −0.25 (−1.68 to 1.18) | § | § | § | § | § | § |
| Extra-articular manifestation | −0.17 (−0.86 to 0.52) | § | § | § | § | § | § |
| QIC of the model | 5439 | 5458 | 5665 | 5579 | 5664 | 5473 | |
*All models are time-lagged (2 years of time lag) and autoregressive (ie, adjusted for mSASSS in the 2 years before). ß reflect progression in mSASSS units over 2 years.
†One patient had a missing in one of the items of the ASDAS (BASDAI question 3) and therefore ASDAS could not be calculated.
‡Not included in the model.
§Not selected during multivariable regression analysis (p ≥ 0.05).
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Activity Index; CRP, C-reactive protein; mSASSS, modified Stoke Ankylosing Spondylitis Spine Score; ESR, erythrocyte sedimentation rate; DMARDs, disease modifying antirheumatic drugs; NSAIDs, non-steroidal anti-inflammatory drugs; QIC, Quasi-likelihood under the Independence model Criterion.