The association between progression of the mSASSS over 2 years and TNFi exposure in patients with axial spondyloarthritis from in the longitudinal generalised estimating equation analysis
| Variable | Univariable analysis β (95% CI) | Multivariable model 1 β (95% CI) | Multivariable model 2 β (95% CI) | Multivariable model 3 β (95% CI) | Multivariable model 4 β (95% CI) | Multivariable model 5 β (95% CI) |
| Any TNFi use in the current 2-year interval | 0.26 (−0.14 to 0.65) | −0.02 (−0.37 to 0.34) | – | – | – | – |
| TNFi for ≥12 months in the current 2-year interval | −0.03 (−0.40 to 0.34) | – | −0.17 (−0.54 to 0.20) | – | – | – |
| Any TNFi use in the previous 2-year interval | −0.31 (−0.61 to 0.00) | – | – | −0.41 (−0.69 to −0.13) | – | – |
| TNFi for ≥12 months in the previous 2-year interval | −0.41 (−0.69 to −0.13) | – | – | – | −0.54 (−0.93 to −0.14) | – |
| TNFi for ≥12 months in the previous and ≥12 months in the current 2-year interval | −0.43 (−0.73 to −0.14) | – | – | – | – | −0.58 (−1.02 to −0.13) |
| Male sex | 0.52 (0.19 to 0.84) | 0.27 (0.01 to 0.53) | 0.27 (0.01 to 0.53) | 0.27 (0.01 to 0.53) | 0.26 (0.00 to 0.52) | 0.27 (0.01 to 0.53) |
| Symptom duration, years | 0.04 (0.00 to 0.08) | 0.00 (−0.03 to 0.03) | 0.01 (−0.03 to 0.04) | 0.01 (−0.02 to 0.04) | 0.01 (−0.02 to 0.05) | 0.01 (−0.02 to 0.05) |
| Time-averaged ASDAS, points | 0.24 (0.00 to 0.47) | 0.20 (−0.03 to 0.42) | 0.19 (−0.03 to 0.41) | 0.18 (−0.04 to 0.40) | 0.18 (−0.04 to 0.39) | 0.18 (−0.03 to 0.40) |
| Current smoking | 0.52 (0.15 to 0.89) | 0.37 (0.08 to 0.65) | 0.36 (0.08 to 0.64) | 0.37 (0.09 to 0.65) | 0.38 (0.10 to 0.66) | 0.38 (0.10 to 0.66) |
| Classification as r-axSpA | 0.61 (0.27 to 0.94) | 0.24 (−0.02 to 0.50) | 0.25 (−0.01 to 0.51) | 0.24 (−0.02 to 0.50) | 0.23 (−0.03 to 0.49) | 0.23 (−0.03 to 0.49) |
| mSASSS, points | 0.10 (0.07 to 0.13) | 0.09 (0.06 to 0.12) | 0.09 (0.06 to 0.12) | 0.09 (0.06 to 0.12) | 0.09 (0.06 to 0.12) | 0.09 (0.06 to 0.12) |
| NSAID score, per 10 points | 0.02 (−0.03 to 0.06) | −0.04 (−0.09 to −0.00) | −0.04 (−0.09 to −0.00) | −0.05 (−0.09 to −0.00) | −0.05 (−0.09 to −0.00) | −0.05 (−0.09 to −0.00) |
ASDAS, Ankylosing Spondylitis Disease Activity Score; axSpA, axial spondyloarthritis; mSASSS, modified Stroke Ankylosing Spondylitis Spine Score; NSAID, non-steroidal anti-inflammatory drugs; r-axSpA, radiographic axSpA; TNFi, tumour necrosis factor alpha inhibitor.