The impact of non‐steroidal anti‐inflammatory drugs on radiographic spinal progression in patients with axial spondyloarthritis: 10‐year results from an inception cohort

Objectives This study aims to investigate the impact of non‐steroidal anti‐inflammatory drug (NSAID) intake on radiographic spinal progression in axial spondyloarthritis (axSpA), considering different NSAID types (COX‐2 inhibitors [COX2i] and non‐selective NSAIDs [ns‐NSAIDs]) and disease subgroups (radiographic (r‐axSpA) and non‐radiographic (nr‐axSpA). Methods Leveraging data from the German Spondyloarthritis Inception Cohort (GESPIC), we conducted analyses on 252 axSpA patients (139 nr‐ axSpA and 113 r‐axSpA), who had minimum 2 sets of spinal radiographs. The outcome was progression in modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) in 2‐year intervals. We fitted sequential conditional mean models by utilizing generalized estimating equations and adjusting for longitudinal repeated measures of exposure and time‐dependent confounders. We report β‐coefficients with 95% confidence intervals (CIs) for outcome reflecting the progression in mSASSS per 10‐point increase in NSAID intake score. Results At baseline, 201 (80.0%) patients were under NSAID treatment, with 46 (18%) taking COX2i and 156 (62%) ns‐NSAIDs and mean total NSAID intake score was 38.3±35.5. A 10‐point increase in NSAID intake score was associated with retardation of radiographic progression (β=‐0.052, 95%CI: ‐0.097, ‐0.007), with this effect being most pronounced in r‐axSpA patients (β=‐0.077, 95%CI: ‐0.152, ‐0.003). COX2i showed a slightly lower point estimate (although not statistically significant) in progression compared to ns‐NSAIDs among all axSpA patients (β= ‐0.061 and ‐0.045, respectively). Conclusions Our findings suggest a beneficial effect of higher NSAID intake, particularly COX2i, on slowing radiographic progression in axSpA. These findings may help inform therapeutic strategies, particularly in r‐axSpA, while further research is needed for nr‐axSpA.