title: Significance of lung shrinkage on CXR as a prognostic factor in patients with idiopathic pulmonary fibrosis.
abstract: OBJECTIVE
  The aim of this study was to determine whether the presence of lung shrinkage on CXR can predict diminished survival in patients with idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP).
  
  
  METHODS
  In a hospital-based cohort study 68 subjects diagnosed with IPF/UIP by surgical lung biopsy or at autopsy were observed for a mean of 7.6 years. The radiographic scores from Cherniack's method, pulmonary function tests, arterial blood gas, and haematological data were obtained at initial presentation. Longitudinal radiographic changes over a mean interval of 2.7 years were measured. Survival analysis was performed using Kaplan-Meier and Cox's proportional hazards regression analysis.
  
  
  RESULTS
  At some point during the observation period 36 (53%) of 68 patients did not exhibit lung shrinkage and 32 (47%) of 68 patients showed lung shrinkage. Patients with lung shrinkage were more likely to have a diminished survival than those with lung preservation; median survival was 4.4 vs 7.8 years, respectively. Lung shrinkage during the observation period (hazard ratio, 3.89; 95% CI = 1.68-9.01; P= 0.001) was associated with lower rates of survival.
  
  
  CONCLUSIONS
  In patients with IPF/UIP, lung shrinkage on CXR during the observation period was a poor prognostic factor.
authors.affiliation: Department of Respiratory Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Hidenobu
authors.initials: H
authors.lastname: Kawabata
authors.forename: Sonoko
authors.initials: S
authors.lastname: Nagai
authors.forename: Michio
authors.initials: M
authors.lastname: Hayashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakamura
authors.forename: Taisi
authors.initials: T
authors.lastname: Nagao
authors.forename: Michio
authors.initials: M
authors.lastname: Shigematsu
authors.forename: Masanori
authors.initials: M
authors.lastname: Kitaichi
authors.forename: Takateru
authors.initials: T
authors.lastname: Izumi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011379:Prognosis; D011658:Pulmonary Fibrosis / Q000097:blood / Q000000981:diagnostic imaging* / Q000401:mortality / Q000473:pathology; D011859:Radiography; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D016019:Survival Analysis