Gender differences in the discriminative value of inflammatory low back pain criteria

Aim: Inflammatory back pain (IBP) is the leading symptom in axial spondyloarthritis (axSpA) and its assessment is crucial for the diagnosis. Our aim was to assess gender specific differences in the discriminative ability of the items and criteria sets in a specific patient population consisting patients with axSpA and other causes of chronic low back pain (LBP). Methods: Patients with chronic LBP with an onset less than 45 years were included and screened for the Assessment of Spondyloarthritis International Society (ASAS) axSpA criteria. Items of IBP, according to Calin, Berlin and ASAS expert criteria were evaluated in patients with axSpA and non-SpA LBP by a blinded researcher. Discriminative ability of the single items and sets were assessed in terms of sensitivity, specificity and area under the curve (AUC) analysis in male and female patients and compared between genders. Results: Single IBP items performed similarly well in men and women, as well as criteria sets. Despite similar discriminative performance of IBP items and criteria sets in both genders, women tend to have slightly better perfor-mance. Our results revealed similar sensitivity but slightly lower specificity for most of the single items and criteria sets compared to previous reports. Conclusion: Gender may have an influence on the discriminative performance of some of the IBP items and criteria sets as well. Calin criteria seem to perform slightly better in both genders than Berlin and ASAS criteria sets.