title: How reliable is the clinical exam in detecting ocular chlamydial infection?
abstract: OBJECTIVE
  To describe the relationship between the clinical exam for trachoma and the polymerase chain reaction (PCR) for ocular chlamydia.
  
  
  METHODS
  One hundred children in a trachoma-endemic area of Ethiopia were examined three times and swabbed twice for PCR analysis. The assays were compared, and an analysis of the variance between exam and PCR was performed.
  
  
  RESULTS
  Inter-examiner agreement was 0.57 (Cohen's kappa), inter-PCR agreement 0.98, and agreement between examiner and PCR, 0.26-0.34. The positive predictive value of the exam in identifying infection was 66%. Inter-examiner variance accounted for 30% of the total variance between the exam and PCR, with the remainder presumably due to an underlying difference in what the exam and PCR measure.
  
  
  CONCLUSIONS
  Despite modest inter-grader reliability and correlation with evidence of infection, the clinical exam is widely used due to its convenience and low cost. Efforts to make laboratory tests for ocular Chlamydia trachomatis more affordable would be useful.
authors.affiliation: FI Proctor Foundation, San Francisco, USA.
authors.forename: Kevin
authors.initials: K
authors.lastname: Miller
authors.forename: Greg
authors.initials: G
authors.lastname: Schmidt
authors.forename: Muluken
authors.initials: M
authors.lastname: Melese
authors.forename: Wondu
authors.initials: W
authors.lastname: Alemayehu
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Yi
authors.forename: Vicky
authors.initials: V
authors.lastname: Cevallos
authors.forename: Cathy
authors.initials: C
authors.lastname: Donnellan
authors.forename: Lynn
authors.initials: L
authors.lastname: Olinger
authors.forename: Demeke
authors.initials: D
authors.lastname: Fantaye
authors.forename: Bruce
authors.initials: B
authors.lastname: Gaynor
authors.forename: John P
authors.initials: JP
authors.lastname: Whitcher
authors.forename: Thomas
authors.initials: T
authors.lastname: Lietman
mesh_terms: D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000235:genetics / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis*; D005002:Ethiopia / Q000453:epidemiology; D006801:Humans; D007223:Infant; D015588:Observer Variation; D010808:Physical Examination; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014141:Trachoma / Q000175:diagnosis* / Q000453:epidemiology / Q000382:microbiology
chemical_list: D004269:DNA, Bacterial