title: Identifying patients with axial spondyloarthritis in primary care: how useful are items indicative of inflammatory back pain?
abstract: BACKGROUND
  The value of clinical items defining inflammatory back pain to identify patients with axial spondyloarthritis (SpA) in primary care is unclear.
  
  
  OBJECTIVE
  To identify predictive clinical parameters for a diagnosis of axial SpA in patients with chronic back pain presenting in primary care.
  
  
  METHODS
  Consecutive patients aged < 45 years (n=950) with back pain for > 2 months who presented to orthopaedic surgeons (n=143) were randomised based on four key questions for referral to rheumatologists (n=36) for diagnosis.
  
  
  RESULTS
  The rheumatologists saw 322 representative patients (mean age 36 years, 50% female, median duration of back pain 30 months). 113 patients (35%) were diagnosed as axial SpA (62% HLA B27+), 47 (15%) as ankylosing spondylitis (AS) and 66 (21%) as axial non-radiographic SpA (nrSpA). Age at onset ≤ 35 years, improvement by exercise, improvement with non-steroidal anti-inflammatory drugs, waking up in the second half of the night and alternating buttock pain were identified as most relevant for diagnosing axial SpA by multiple regression analysis. Differences between AS and nrSpA were detected. No single item was predictive, but ≥ 3 items proved useful for good sensitivity and specificity by receiver operating characteristic modelling.
  
  
  CONCLUSIONS
  This study shows that a preselection in primary care of patients with back pain based on a combination of clinical items is useful to facilitate the diagnosis of axial SpA.
authors.affiliation: Rheumazentrum Ruhrgebiet, Landgrafenstr.15, 44652 Herne, Germany. j.braun@rheumazentrum-ruhrgebiet.de
authors.forename: A
authors.initials: A
authors.lastname: Braun
authors.forename: E
authors.initials: E
authors.lastname: Saracbasi
authors.forename: J
authors.initials: J
authors.lastname: Grifka
authors.forename: J
authors.initials: J
authors.lastname: Schnitker
authors.forename: J
authors.initials: J
authors.lastname: Braun
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D017668:Age of Onset; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D001368:Axis, Cervical Vertebra; D001416:Back Pain / Q000209:etiology*; D002908:Chronic Disease; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D004812:Epidemiologic Methods; D005260:Female; D015796:HLA-B27 Antigen / Q000032:analysis; D006801:Humans; D008297:Male; D018579:Patient Selection; D011320:Primary Health Care / Q000379:methods; D012017:Referral and Consultation; D025241:Spondylarthritis / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy; D013167:Spondylitis, Ankylosing / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D015796:HLA-B27 Antigen