title: Inter-Rater Agreement between Trachoma Graders: Comparison of Grades Given in Field Conditions versus Grades from Photographic Review.
abstract: OBJECTIVE
  Trachoma surveillance is most commonly performed by direct observation, usually by non-ophthalmologists using the World Health Organization (WHO) simplified grading system. However, conjunctival photographs may offer several benefits over direct clinical observation, including the potential for greater inter-rater agreement. This study assesses whether inter-rater agreement of trachoma grading differs when trained graders review conjunctival photographs compared to when they perform conjunctival examinations in the field.
  
  
  METHODS
  Three trained trachoma graders each performed an independent examination of the everted right tarsal conjunctiva of 269 children aged 0-9 years, and then reviewed photographs of these same conjunctivae in a random order. For each eye, the grader documented the presence or absence of follicular trachoma (TF) and intense trachomatous inflammation (TI) according to the WHO simplified grading system.
  
  
  RESULTS
  Inter-rater agreement for the grade of TF was significantly higher in the field (kappa coefficient, κ, 0.73, 95% confidence interval, CI 0.67-0.80) than by photographic review (κ = 0.55, 95% CI 0.49-0.63; difference in κ between field grading and photo grading 0.18, 95% CI 0.09-0.26). When field and photographic grades were each assessed as the consensus grade from the three graders, agreement between in-field and photographic graders was high for TF (κ = 0.75, 95% CI 0.68-0.84).
  
  
  CONCLUSIONS
  In an area with hyperendemic trachoma, inter-rater agreement was lower for photographic assessment of trachoma than for in-field assessment. However, the trachoma grade reached by a consensus of photographic graders agreed well with the grade given by a consensus of in-field graders.
authors.affiliation: The Carter Center Ethiopia , Addis Ababa , Ethiopia .
authors.forename: Sintayehu
authors.initials: S
authors.lastname: Gebresillasie
authors.forename: Zerihun
authors.initials: Z
authors.lastname: Tadesse
authors.forename: Ayalew
authors.initials: A
authors.lastname: Shiferaw
authors.forename: Sun N
authors.initials: SN
authors.lastname: Yu
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Stoller
authors.forename: Zhaoxia
authors.initials: Z
authors.lastname: Zhou
authors.forename: Paul M
authors.initials: PM
authors.lastname: Emerson
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Gaynor
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lietman
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Keenan
mesh_terms: D000900:Anti-Bacterial Agents / Q000008:administration & dosage; D017963:Azithromycin / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D003228:Conjunctiva / Q000473:pathology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D015588:Observer Variation; D010781:Photography / Q000145:classification*; D010808:Physical Examination / Q000145:classification*; D015203:Reproducibility of Results; D014141:Trachoma / Q000145:classification* / Q000175:diagnosis* / Q000188:drug therapy
chemical_list: D000900:Anti-Bacterial Agents; D017963:Azithromycin
keywords: Diagnosis; inter-rater agreement; observer variation; photography; trachoma