title: Importance of including borderline cases in trachoma grader certification.
abstract: We assessed trachoma grading agreement among field graders using photographs that included the complete spectrum of disease and compared it with cases where there was consensus among experienced graders. Trained photographers took photographs of children's conjunctiva during a clinical trial in Ethiopia. We calculated κ-agreement statistics using a complete set of 60 cases and then recalculated the κ using a consensus set where cases were limited to those cases with agreement among experienced graders. When the complete set of 60 cases was used, agreement was moderate (κ = 0.61, 95% confidence interval [95% CI] = 0.56-0.67). When the consensus set was used, agreement improved significantly (κ = 0.75, 95% CI = 0.68-0.80). The κ of the consensus set was higher than the complete set by 0.14 (95% CI = 0.12-0.16) (P < 0.001). If testing sets remove difficult-to-grade cases, agreement in trachoma grading may be higher than actually seen in population-based trachoma surveys.
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia bruce.gaynor@ucsf.edu.
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Gaynor
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Abdou
authors.initials: A
authors.lastname: Amza
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Sintayehu
authors.initials: S
authors.lastname: Gebresailassie
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Boubacar
authors.initials: B
authors.lastname: Kadri
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Baido
authors.initials: B
authors.lastname: Nassirou
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Nicole E
authors.initials: NE
authors.lastname: Stoller
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Sun N
authors.initials: SN
authors.lastname: Yu
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Puja A
authors.initials: PA
authors.lastname: Cuddapah
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Jeremy D
authors.initials: JD
authors.lastname: Keenan
authors.affiliation: F. I. Proctor Foundation, Department of Ophthalmology, Department of Epidemiology and Biostatistics, Institute for Global Health, University of California, San Francisco, California; Programme National de Lutte Contre la Cecité Niamey, Niger; The Carter Center, Addis Ababa, Ethiopia.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Lietman
mesh_terms: D002568:Certification / Q000592:standards*; D002675:Child, Preschool; D005002:Ethiopia; D006801:Humans; D007223:Infant; D015588:Observer Variation; D010781:Photography; D015203:Reproducibility of Results; D014141:Trachoma / Q000145:classification* / Q000175:diagnosis