Reliability of IBP Criteria & Activity Scores in Patients With AxSpA

Study Overview
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Brief Summary
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The current ASAS classification of AxSpA relies either on sacroiliitis on imaging plus one SpA feature (imaging arm) or HLA-B27 antigen plus two SpA features (clinical arm), in a patient with chronic back pain and age at onset of less than 45 years. IBP which is a major symptom of SpA depends more on patient's perception which is not usually accurate. As well, disease activity is measured by ASDAS, BASDAI, and BASFAI which depend more on subjective measures. Assessment of reliability of IBP criteria, ASDAS, BASDAI, and BASFAI in diagnosis and evaluation of activity of AxSpA is essential for better health care.

Detailed Description
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Axial spondyloarthritis (AxSpA) is a chronic inflammatory disease that affects the axial skeleton mainly leading to significant pain and disability. Early diagnosis of AxSpA is important for better management of symptoms and to limit spinal damage. The last classification of AxSpA is ASAS classification criteria which relies either on sacroiliitis on imaging plus one SpA feature (imaging arm) or HLA-B27 antigen plus two SpA features (clinical arm), in a patient with chronic back pain and age at onset of less than 45 years. Inflammatory back pain (IBP) is the key clinical symptom of AxSpA and is often present at disease onset. There are different sets of IBP criteria which include the Calin criteria , Berlin criteria, and the Assessment of SpondyloArthritis international Society (ASAS) IBP experts criteria. These sets when assessed by different rheumatologists had different sensitivity and specificity. As IBP has certain characters, taking the clinical history has been considered as a screening test for patients with chronic back pain to identify patients with AxSpA. But, the value of this screening test has been questioned. Disease activity in AxSpA has been measured by the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). It has been used extensively since 1994 but with some limitations as it does not include the physician's assessment of the disease and does not assess the impact of specific clinical factors. The Bath Ankylosing Spondylitis Functional Index (BASFI) has been also developed as an approach to defining and monitoring functional ability in patients with AxSpA. ASAS developed a disease activity score for patient with AxSpA which is called Ankylosing Spondylitis Disease Activity Score (ASDAS) that combines patient-reported assessments with acute phase reactants (C-reactive protein [CRP] or erythrocyte sedimentation rate [ESR]). However, it is based largely on subjective measures, and lacks objective biomarker of disease activity. The evaluation of disease activity in AxSpA is complex and multifactorial. Also, patients and physicians have different perspectives of the disease and none of the current single-item or combined indexes adequately unifies both perspectives.

Official Title
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Reliability of Inflammatory Back Pain Criteria and Activity Scores in Patients With Axial Spondyloarthritis

Conditions
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Axial Spondyloarthritis, Inflammatory Back Pain

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Group 1 Patients diagnosed as AxSpA. Age > 18 years and < 45 years at onset of the disease. Group 2 Patients diagnosed as chronic mechanical back pain. Age > 18 years and < 45 years at onset of the disease. Exclusion Criteria: Patients having acute or subacute back pain. Patients having back pain referred from another site. Patients with any other autoimmune disease: rheumatoid arthritis, systemic lupus erythematosus, Behçet's disease… etc.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| patients with axial spondyloarthritis<br>ASAS classification criteria which relies either on sacroiliitis on imaging plus one SpA feature (imaging arm) or HLA-B27 antigen plus two SpA features (clinical arm), in a patient with chronic back pain and age at onset of less than 45 years | |
| patients with mechanical back pain<br>Patients diagnosed as chronic (more than 3 months) mechanical back pain, the diagnosis has been made prior to the study by the treating specialist, these patients are herein as a control group | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| assessment of reliability, sensitivity, and specificity of inflammatory back pain criteria (the Assessment of SpondyloArthritis international Society IBP experts criteria) depending on a gold standard which is the global evaluation of the rheumatologist. | Assessment of reliability of each item and the whole set of inflammatory back pain criteria ( the Assessment of SpondyloArthritis international Society (ASAS) IBP experts criteria) depending on a gold standard which is the global evaluation of expert rheumatologist: is it inflammatory or mechanical back pain. The Assessment of SpondyloArthritis international Society (ASAS) IBP experts criteria includes 5 items: age at onset ≤ 40 years, insidious onset, improvement with exercise, no improvement with rest, pain at night. This set of criteria is achieved if at least four parameters are met. | 8/2021 to 5/2022 | 
| assessment of reliability of Ankylosing Spondylitis Disease Activity Score in axial spondyloarthritis patients. | Ankylosing Spondylitis Disease Activity Score (ASDAS-CRP) includes 4 questions about disease activity (Axial pain, Peripheral Pain/Swelling, Duration of Morning Stiffness, activity of the disease on average during the last week) and CRP. Each question has a score from 0 to 10. 0 means no, and 10 means sever. ASDAS_CRP = 0.121 × total back pain + 0.110 × patient global + 0.073 × peripheral pain / swelling + 0.058 × duration of morning stiffness + 0.579 × Ln (CRP+1). ASDAS scores : <1.3 inactive disease and <2.1low disease activity, ≤3.5 high disease activity, and >3.5 very high disease activity. The score is applied to the same group of patients by 2 rheumatologists. The scores of each question and the total score that detected by the two rheumatologists are compared to detect agreement between the two rheumatologist and assess reliability of this score | 8/2021 to 5/2022 |