title: Validation of a patient self-reported screening questionnaire for axial spondyloarthropathy in a UK Population.
abstract: METHODS
  Cross-sectional cohort study.
  
  
  OBJECTIVE
  The aim of this study was to develop and validate a patient-completed screening questionnaire for axial spondyloarthropathy for use in the United Kingdom.
  
  
  BACKGROUND
  Axial spondyloarthropathy (axial SpA) can be difficult to diagnose in the early stages of disease, leading to diagnostic delay and morbidity. Existing population screening tools lack sensitivity or have not been validated in the UK population.
  
  
  METHODS
  Questionnaires were sent to 295 patients with definite ankylosing spondylitis (meeting modified New York criteria), nonradiographical axial SpA (sacroiliitis on magnetic resonance imaging), or mechanical back pain. Responses from 190 patients were analyzed. Binary logistic regression was used to develop a model differentiating inflammatory from mechanical pain.
  
  
  RESULTS
  The final model (male sex, onset of symptoms by age 33 years, no radiation of pain, pain gets better as day goes on, pain increases with rest, and personal history of iritis) correctly classified 86% of cases with Nagelkerke R = 0.486. A numerical score (with 1 point assigned for each feature present) was calculated and receiver operating characteristic curve was constructed, with area under the curve of 0.911 (95% confidence interval: 0.87-0.96). A score of ≥3/6 had sensitivity of 75.6% and specificity of 87.9% for inflammation.
  
  
  CONCLUSIONS
  We have developed a model that differentiates patients with ankylosing spondylitis/axial SpA from those with mechanical spinal disease and can be used as a self-completed screening tool.
authors.affiliation: Departments of Rheumatology, Norfolk and Norwich University Hospital, Norwich, Norfolk, United Kingdom NR4 7UY. louise.hamilton@nnuh.nhs.uk
authors.forename: Louise
authors.initials: L
authors.lastname: Hamilton
authors.forename: Alex
authors.initials: A
authors.lastname: Macgregor
authors.forename: David
authors.initials: D
authors.lastname: Newman
authors.forename: Abdelghani
authors.initials: A
authors.lastname: Belkhiri
authors.forename: Andoni
authors.initials: A
authors.lastname: Toms
authors.forename: Karl
authors.initials: K
authors.lastname: Gaffney
mesh_terms: D000328:Adult; D001416:Back Pain / Q000175:diagnosis; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D015203:Reproducibility of Results; D058566:Sacroiliitis / Q000175:diagnosis; D057566:Self Report; D012680:Sensitivity and Specificity; D025242:Spondylarthropathies / Q000175:diagnosis*; D013167:Spondylitis, Ankylosing / Q000175:diagnosis; D011795:Surveys and Questionnaires; D006113:United Kingdom