title: New criteria for inflammatory back pain in patients with chronic back pain: a real patient exercise by experts from the Assessment of SpondyloArthritis international Society (ASAS).
abstract: OBJECTIVE
  Inflammatory back pain (IBP) is an important clinical symptom in patients with axial spondyloarthritis (SpA), and relevant for classification and diagnosis. In the present report, a new approach for the development of IBP classification criteria is discussed.
  
  
  METHODS
  Rheumatologists (n = 13) who are experts in SpA took part in a 2-day international workshop to investigate 20 patients with back pain and possible SpA. Each expert documented the presence/absence of clinical parameters typical for IBP, and judged whether IBP was considered present or absent based on the received information. This expert judgement was used as the dependent variable in a logistic regression analysis in order to identify those individual IBP parameters that contributed best to a diagnosis of IBP. The new set of IBP criteria was validated in a separate cohort of patients (n = 648).
  
  
  RESULTS
  Five parameters best explained IBP according to the experts. These were: (1) improvement with exercise (odds ratio (OR) 23.1); (2) pain at night (OR 20.4); (3) insidious onset (OR 12.7); (4) age at onset <40 years (OR 9.9); and (5) no improvement with rest (OR 7.7). If at least four out of these five parameters were fulfilled, the criteria had a sensitivity of 77.0% and specificity of 91.7% in the patients participating in the workshop, and 79.6% and 72.4%, respectively, in the validation cohort.
  
  
  CONCLUSIONS
  This new approach with real patients defines a set of IBP definition criteria using overall expert judgement on IBP as the gold standard. The IBP experts' criteria are robust, easy to apply and have good face validity.
authors.affiliation: Medizinische Klinik I, Charité - Campus Benjamin Franklin, Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Sieper
authors.forename: D
authors.initials: D
authors.lastname: van der Heijde
authors.forename: R
authors.initials: R
authors.lastname: Landewé
authors.forename: J
authors.initials: J
authors.lastname: Brandt
authors.forename: R
authors.initials: R
authors.lastname: Burgos-Vagas
authors.forename: E
authors.initials: E
authors.lastname: Collantes-Estevez
authors.forename: B
authors.initials: B
authors.lastname: Dijkmans
authors.forename: M
authors.initials: M
authors.lastname: Dougados
authors.forename: M A
authors.initials: MA
authors.lastname: Khan
authors.forename: M
authors.initials: M
authors.lastname: Leirisalo-Repo
authors.forename: S
authors.initials: S
authors.lastname: van der Linden
authors.forename: W P
authors.initials: WP
authors.lastname: Maksymowych
authors.forename: H
authors.initials: H
authors.lastname: Mielants
authors.forename: I
authors.initials: I
authors.lastname: Olivieri
authors.forename: M
authors.initials: M
authors.lastname: Rudwaleit
mesh_terms: D000328:Adult; D017668:Age of Onset; D001416:Back Pain / Q000209:etiology* / Q000276:immunology / Q000628:therapy; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005081:Exercise Therapy; D005104:Expert Testimony / Q000379:methods*; D005260:Female; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D012146:Rest; D012680:Sensitivity and Specificity; D017211:Treatment Failure