ABSTRACT. Objective. To estimate the prevalence of inflammatory back pain (IBP) and axial spondyloarthritis (axSpA) using the Assessment of SpondyloArthritis International Society (ASAS) classification criteria among employees in a university. Methods. In the first stage of the study, a face-to-face interview was done using a standard questionnaire to investigate IBP in 381 subjects randomly selected from 2894 employees at Dokuz Eylul University in Izmir, Turkey. In the second stage, subjects with back pain for ≥ 3 months and age at onset < 45 years were evaluated for axSpA using the ASAS criteria. Both the European Spondyloarthropathy Study Group (ESSG) criteria and Amor criteria were used for the classification of the whole group of spondyloarthritis (SpA). Results. There were 131 male and 250 female subjects (mean age: 38.0 yrs). Twenty-five subjects (6.6%) were classified as having IBP according to the ASAS criteria. The prevalence of IBP according to the Berlin and Calin criteria was 7.1% and 21.5%, respectively. The prevalence of axSpA was estimated at 1.3% according to the ASAS classification criteria (0.5% for radiographic axSpA and 0.8% for nonradiographic axSpA). A total of 7 patients (1.8%) fulfilled both the Amor and ESSG criteria for the whole group of SpA. Conclusion. This is the first prevalence study of IBP and axSpA using ASAS classification criteria in the Turkish population. Spondyloarthritides are among the most prevalent inflammatory rheumatic diseases 1 . There is a considerable diagnostic delay (8.9 yrs) in ankylosing spondylitis (AS), the prototype of this group, mainly because of the requirement of radiographic sacroiliitis for its diagnosis 2 . Low awareness of inflammatory back pain (IBP), the first and most common symptom of spondyloarthritis (SpA), in daily practice is also a major reason for the diagnostic delay 3 . New classification criteria developed by the Assessment of SpondyloArthritis International Society (ASAS) provide that patients with SpA can be classified as either patients with axial SpA (axSpA) or those with peripheral SpA. The ASAS axSpA criteria cover the entire spectrum of axial disease including AS and nonradiographic axSpA (nr-axSpA) MATERIALS AND METHODS We conducted our study at the Health Sciences Campus at Dokuz Eylul University in Izmir, which has 2894 medical and nonmedical staff aged between 18 and 67 years. A sample of 395 subjects was selected randomly by a computer from the list of all employees, based on the IBP prevalence of 5% in the general population 5 , using OpenEpi (version 2.3) and CI ± 2%. A total of 381 of these 395 subjects agreed to participate, an acceptance rate of 96.5%. In the first stage of the study, 6 trained medical students, using a standard questionnaire, interviewed participants face to face. Questionnaire responses were used to determine whether participants met the ASAS criteria for IBP 10 . Subjects were also evaluated for IBP based on the Berlin 11 and Calin criteria 12 In the second stage, the subjects with back pain for more than 3 month
