Background and aims: Both peripheral and axial spondyloarthritis [SpA] occur in inflammatory bowel disease [IBD] and represent the commonest extra-intestinal manifestation. We aimed to develop an easy and quick questionnaire through psychometric analysis, to identify peripheral and axial SpA in IBD patients within an integrated combined multidisciplinary rheumatological-gastroenterology clinic.
Methods: Initially, SpA-IBD experts generated a 42-item list covering SpA manifestations including spinal, articular, and entheseal involvement. The new questionnaire was administered before routine clinical IBD assessment. On the same day, rheumatological assessment, blinded to both history and questionnaire results, was performed to explore the presence of the Assessment of SpondyloArthritis International Society [ASAS] criteria for SpA, diagnostic criteria for fibromyalgia [FM], and non-specific low back pain [NSLB]. Factorial analysis of questionnaire items to identify the main factors-receiver operating characteristic [ROC] curves for sensitivity/specificity and Youden index for cut-off-were performed.
Results: Of the 181 consecutive patients, 56 met the ASAS SpA criteria [prevalence of 30%] with 10 new cases detected [5.5%: seven peripheral and three axial]. Through the psychometric and factorial analysis, we selected 14 items for the final questionnaire [named IBIS-Q]. The IBIS-Q was quick and performed well for detection of axial SpA and peripheral SpA (area under the curve [AUC] 0.88 with 95% confidence interval [CI] 0.830.93). A cut-off of three positive questions had a sensitivity 93% and specificity 77% for SpA patient identification.
Conclusions: The IBIS-Q is a useful and simple tool to use in IBD clinics for SpA detection, with a good statistical performance. Further studies are needed to validate it.
Keywords: Inflammatory bowel disease; screening; spondyloarthritis.
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