title: Chest radiograph abnormalities associated with tuberculosis: reproducibility and yield of active cases.
abstract: METHODS
  Tertiary care referral centre specialising in respiratory diseases.
  
  
  OBJECTIVE
  Chest radiography is a major screening and diagnostic tool for tuberculosis (TB). We evaluated the reproducibility of a radiographic classification system for screening for active TB of immigration applicants to Canada. We also evaluated the validity of this classification system for detection of prevalent active TB among the screened applicants, as well as tuberculin-positive close contacts and symptomatic patients.
  
  
  METHODS
  Reproducibility was assessed by re-reading a randomly selected 10% sample of screening chest films. Validity was estimated from the final clinical and microbiologic diagnosis of patients undergoing detailed clinical evaluation.
  
  
  RESULTS
  Inter-reader agreement using five broad categories was moderate (kappas of 0.44-0.56), while intra-reader agreement was substantial (kappas of 0.59-0.72). After adjustment for age and patient group, the adjusted odds of active tuberculosis, relative to normal or minor findings or granulomas, for fibronodular changes was 10.2 (95% confidence interval [CI] 3.2-33), for mass or pleural effusion it was 11.6 (95%CI 3.6-37), and for parenchymal infiltrate it was 46.1 (95%CI 18-117). Among tuberculin-positive close contacts, the probability of active tuberculosis was more than 50% if the radiographs showed any mass, pleural disease, or parenchymal infiltrates.
  
  
  CONCLUSIONS
  A simple classification of TB-related chest radiographic abnormalities into five broad categories had moderate to substantial reproducibility of readings, with reasonable validity.
authors.affiliation: Internal Medicine, Brigham & Women's Hospital, Boston, Massachusetts, USA.
authors.forename: S
authors.initials: S
authors.lastname: Graham
authors.forename: Gupta K
authors.initials: GK
authors.lastname: Das
authors.forename: R J
authors.initials: RJ
authors.lastname: Hidvegi
authors.forename: R
authors.initials: R
authors.lastname: Hanson
authors.forename: J
authors.initials: J
authors.lastname: Kosiuk
authors.forename: Zahrani K
authors.initials: ZK
authors.lastname: Al
authors.forename: D
authors.initials: D
authors.lastname: Menzies
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000554:Ambulatory Care Facilities; D002170:Canada / Q000453:epidemiology; D004641:Emigration and Immigration; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011322:Primary Prevention / Q000458:organization & administration*; D013902:Radiography, Thoracic / Q000706:statistics & numerical data*; D015203:Reproducibility of Results; D012307:Risk Factors; D012720:Severity of Illness Index; D017678:Sex Distribution; D014397:Tuberculosis, Pulmonary / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D014505:Urban Population