Ab0938 Performance of Inflammatory Back Pain Criteria for Spondylarthritis: Asas Criteria Might Have Overall Better Performance

Objectives: To evaluate the performance characteristics of inflammatory low back pain (IBP) criteria sets and to demonstrate the discriminative values of individual items of IBP criteria in patients with axSpA. Methods: A total 706 patients referred to a single center with back pain and a suspicion of spondyloarthritis (SpA) were included in this analysis. According to ASAS criteria, 568 patients were classified as axial SpA (axSpA) (37.9% female; mean age: 39.9 ±11.6 years) and 138 were classified as non-SpA (72.5% female; mean age: 36.6 ±10.2 years) by the physician. Demographic and clinical characteristics were collected by using a standardized form. Calin, Berlin and ASAS criteria were used for IBA classification. A BASDAI score of ≥4 or an ASDAS score of ≥2.1 used as cut of for the definition of active disease. Results: HLA B27 positivity, male sex were higher and duration of back pain was found to be longer in patients classified as axSpA. Interestingly more patients were classified as active according to BASDAI score in non-SpA group, however as expected mean serum CRP level was higher among patients with axSpA. The demographic and disease related characteristics were summarized in Table 1. It was observed that a significant proportion of patients in non-SpA could be classified as IBA (79.7%-62.3%) according to different criteria sets. The sensitivities of Calin, Berlin, ASAS criteria sets in AxSpA were 90.3%, 77.0%, and 82.6%, respectively. Berlin and ASAS criteria sets had better specificity in comparison with Calin criteria. In addition diagnostic Odds of ASAS set was found to be a bit higher. Morning stiffness, improvement with exercise, and insidious onset items were significantly higher in the axSpA group. In addition, all components of the Berlin criteria for IBA were significantly different between the axSpA and non-SpA groups (Table 1). Conclusion: In this group of patients referred with back pain and a suspicion of axSpA demonstrated that considerable proportion of patients who could not be classified as axSpA might have IBA according to the different IBA criteria sets. However ASAS and Berlin crfiteri may be more specific for axSpA. In our study group overall diagnostic performance of ASAS criteria might be better. REFERENCES: NIL. Acknowledgements: Thank you for your scientific support. Disclosure of Interests: None declared.