Background Spondyloarthritides (SpA) and inflammatory bowel disease (IBD) are immune‐mediated diseases with overlap in clinical and immunological features. However, temporal correlation of SpA and IBD in individual patients and risk factors are not well characterized. Methods We conducted a nationwide population‐based study between January 1, 1998 and July 31, 2022 to determine SpA prevalence preceding and its incidence following IBD diagnosis. Using cross‐linked register data, we identified individuals with IBD diagnosis and matched them to individuals without IBD. Using logistic regression, we determined the odds of SpA preceding IBD diagnosis and using Cox regression, the hazard of new‐onset SpA following IBD diagnosis. Findings Of 102,648 individuals included in the study, 17,108 (16.7%) individuals were diagnosed with IBD. The aOR of SpA in the 8‐year period preceding IBD, Crohn's disease (CD), or ulcerative colitis (UC) diagnosis, compared to matched individuals, was 1.95 (95% CI 1.78, 2.14), 2.84 (95% CI 2.43, 3.32), and 1.61 (95% CI 1.43, 1.81), respectively. The aHR of SpA following IBD, CD, and UC diagnosis, compared to matched individuals, was 2.51 (95% CI 2.34, 2.70), 3.17 (95% CI 2.81, 3.59), and 2.24 (95% CI 2.05, 2.45), respectively. SpA prevalence demonstrated temporal variability, with increase during the few years around IBD diagnosis. Associations were stronger for axial SpA, and among women and young adults preceding IBD diagnosis. Interpretation In a population‐based cohort, we report that SpA diagnosis is associated with IBD preceding and following its diagnosis. We demonstrate temporal variability and highlight clinical variables associated with SpA in IBD.
Scott et al. (Thu,) studied this question.