Assessing rheumatologists’ attitudes and utilization of classification criteria for ankylosing spondylitis and axial spondyloarthritis: a global effort

This study aims to assess rheumatologists’ perceptions, utilization patterns, and attitudes towards the modified New York (mNY) criteria for ankylosing spondylitis (AS) and Assessment of SpondyloArthritis International Society (ASAS) criteria for axial spondyloarthritis (axSpA). Members of the national rheumatology societies in five countries (United States of America (USA), Canada, India, Turkey, and Brazil) were invited to participate in a survey containing questions regarding rheumatologists’ familiarity, and use of AS and axSpA classification criteria in daily practice, perceived specificity of spondyloarthritis features in making the diagnosis, patterns of imaging tests performed in daily practice, and their opinion about the need for modification of current classification criteria. The responses were analyzed by gender, age, years in practice, as well as by country of practice. Descriptive statistics, t test, and chi-square test were used for comparison of groups. Approximately 6% rheumatologists (478 out of 8021 professional association members) from five countries completed the survey. The country-specific response rates were Brazil 4%, USA 4.3%, India 11%, Canada 14%, and Turkey 29%, though the overall contributions from individual countries were USA 47%, India 14.9%, Brazil 13.8%, Turkey 12.8%, and Canada 8.8%. The mean age of respondents was 50 years (± 11.8), 31% were females and 90% spent majority (> 75%) of their time in clinical practice. The mNY and ASAS criteria were regularly used in clinical practice by 44 and 66% of responders, respectively. Those reporting “always” using ASAS criteria were more likely to be women (p = 0.006), and within 5 years of completing rheumatology training. Vast majority (74%) regarded Inflammatory Back Pain (IBP) as a specific feature for axSpA. Majority (50 and 60%, respectively) regarded uveitis and dactylitis as “very specific” features helping them make the diagnosis of axSpA, whereas heel enthesitis, peripheral inflammatory arthritis, and response to NSAIDs were considered “somewhat specific” by 50% of the responders. Less than half (47%) of the responders used the mNY grading for X-ray of SI joints. In the case of normal X-ray of SI joint, the use of MRI was more frequent than CT scan (83.6 vs. 10.9%) in assessing for sacroiliitis. If sacroiliitis was not seen on X-rays, the likelihood of ordering MRI was significantly higher among rheumatologists completing training within  25 years prior (90 vs. 75%, p = 0.007). Overall, 70% thought that ASAS criteria were adequately specific for clinical trials. However, 42% respondents still felt a need to modify ASAS classification criteria for axSpA. Also, 46% respondents felt that mNY criteria should be modified. In the absence of diagnostic criteria, majority of rheumatologists are using the classification criteria for diagnosis of axSpA. Though axSpA classification criteria are perceived to be specific for clinical trials, 40% rheumatologists feel the need to modify these criteria.