title: Inter-rater agreement in the assessment of abnormal chest X-ray findings for tuberculosis between two Asian countries.
abstract: BACKGROUND
  Inter-rater agreement in the interpretation of chest X-ray (CXR) films is crucial for clinical and epidemiological studies of tuberculosis. We compared the readings of CXR films used for a survey of tuberculosis between raters from two Asian countries.
  
  
  METHODS
  Of the 11,624 people enrolled in a prevalence survey in Hanoi, Viet Nam, in 2003, we studied 258 individuals whose CXR films did not exclude the possibility of active tuberculosis. Follow-up films obtained from accessible individuals in 2006 were also analyzed. Two Japanese and two Vietnamese raters read the CXR films based on a coding system proposed by Den Boon et al. and another system newly developed in this study. Inter-rater agreement was evaluated by kappa statistics. Marginal homogeneity was evaluated by the generalized estimating equation (GEE).
  
  
  RESULTS
  CXR findings suspected of tuberculosis differed between the four raters. The frequencies of infiltrates and fibrosis/scarring detected on the films significantly differed between the raters from the two countries (P < 0.0001 and P = 0.0082, respectively, by GEE). The definition of findings such as primary cavity, used in the coding systems also affected the degree of agreement.
  
  
  CONCLUSIONS
  CXR findings were inconsistent between the raters with different backgrounds. High inter-rater agreement is a component necessary for an optimal CXR coding system, particularly in international studies. An analysis of reading results and a thorough discussion to achieve a consensus would be necessary to achieve further consistency and high quality of reading.
authors.affiliation: National Center for Global Health and Medicine, Tokyo, Japan.
authors.forename: Shinsaku
authors.initials: S
authors.lastname: Sakurada
authors.forename: Nguyen T L
authors.initials: NT
authors.lastname: Hang
authors.forename: Naoki
authors.initials: N
authors.lastname: Ishizuka
authors.forename: Emiko
authors.initials: E
authors.lastname: Toyota
authors.forename: Le D
authors.initials: le D
authors.lastname: Hung
authors.forename: Pham T
authors.initials: PT
authors.lastname: Chuc
authors.forename: Luu T
authors.initials: LT
authors.lastname: Lien
authors.forename: Pham H
authors.initials: PH
authors.lastname: Thuong
authors.forename: Pham T N
authors.initials: PT
authors.lastname: Bich
authors.forename: Naoto
authors.initials: N
authors.lastname: Keicho
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Kobayashi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006302:Health Services Research; D006801:Humans; D007564:Japan; D008168:Lung / Q000000981:diagnostic imaging* / Q000473:pathology*; D008875:Middle Aged; D015588:Observer Variation; D013902:Radiography, Thoracic / Q000706:statistics & numerical data*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000473:pathology*; D014744:Vietnam; D055815:Young Adult