The association between progression ≥2 mSASSS points and formation of ≥1 new syndesmophyte over 2 years and TNFi exposure in patients with axial spondyloarthritis in a binomial generalised estimating equation analysis
| Model* | TNFi exposure definition | Reference | Progression ≥2 mSASSS points OR (95% CI) | Formation of ≥1 new syndesmophyte OR (95% CI) |
| 1 | Any TNFi use in the current 2-year interval | No TNFi use in the current 2-ear interval | 1.39 (0.64 to 3.01) | 1.18 (0.50 to 2.79) |
| 2 | TNFi for ≥12 months in the current 2-year interval | No TNFi for ≥12 months in the current 2-year interval | 0.96 (0.35 to 2.66) | 0.75 (0.25 to 2.28) |
| 3 | Any TNFi use in the previous 2-year interval | No TNFi use in the previous 2-year interval | 0.30 (0.08 to 1.20) | 0.31 (0.10 to 0.95) |
| 4 | TNFi for ≥12 months in the previous 2-year interval | No TNFi for ≥12 months in the previous 2-year interval | 0.21 (0.02 to 3.08) | 0.36 (0.12 to 1.07) |
| 5 | TNFi for ≥12 months in the previous and ≥12 months in the current 2-year interval | No TNFi for ≥12 months in the previous and ≥12 months in the current 2-year interval | 0.29 (0.02 to 4.86) | 0.43 (0.12 to 1.55) |
*Parameter estimates from the multivariable models adjusted for sex, symptom duration at the beginning of the current 2-year interval, time-averaged ASDAS in the current 2-year interval, smoking in the current 2-year interval, classification as radiographic axSpA, mSASSS at the beginning of the current 2-year interval and NSAID intake score.
ASDAS, Ankylosing Spondylitis Disease Activity Score; axSpA, axial Spondyloarthritis; mSASSS, modified Stroke Anlylosing Spondylitis Spine Score; NSAID, non-steroidal anti-inflammatory drugs; TNFi, tumour necrosis factor alpha inhibitor.