title: Diagnostic disparity of previous and revised American Thoracic Society guidelines for idiopathic pulmonary fibrosis.
abstract: BACKGROUND
  A revised guideline for the diagnosis of idiopathic pulmonary fibrosis (IPF) was formulated by the American Thoracic Society (ATS) in 2011 to improve disease diagnosis and provide a simplified algorithm for clinicians. The impact of these revisions on patient classification, however, remain unclear.
  
  
  OBJECTIVE
  To examine the concordance between diagnostic guidelines to understand how revisions impact patient classification.
  
  
  METHODS
  A cohort of 54 patients with either suspected IPF or a working diagnosis of IPF was evaluated in a retrospective chart review, in which patient data were examined according to previous and revised ATS guidelines. Patient characteristics influencing the fulfillment of diagnostic criteria were compared using one-way ANOVA and χ(2) tests.
  
  
  RESULTS
  Revised and previous guideline criteria for IPF were met in 78% and 83% of patients, respectively. Revised guidelines modified a classification based on previous guidelines in 28% of cases. Fifteen percent of patients meeting previous ATS guidelines failed to meet revised criteria due to a lack of honeycombing on high-resolution computed tomography and the absence of a surgical lung biopsy. Patients failing to meet previous and revised diagnostic criteria for IPF were younger.
  
  
  CONCLUSIONS
  The revised guidelines for the diagnosis of IPF classify a substantial proportion of patients differently than the previous guidelines.
authors.forename: Lee
authors.initials: L
authors.lastname: Fidler
authors.forename: Shane
authors.initials: S
authors.lastname: Shapera
authors.forename: Shikha
authors.initials: S
authors.lastname: Mittoo
authors.forename: Theodore K
authors.initials: TK
authors.lastname: Marras
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D017410:Practice Guidelines as Topic; D012189:Retrospective Studies; D012955:Societies, Medical