Operational evaluation of the use of photographs for grading active trachoma.
We evaluated the reliability of photographs to verify field diagnoses of active trachoma. We examined 956 residents of a trachoma-endemic village for signs of trachoma using the World Health Organization simplified grading system. Two photographs of the right eye of 948 persons were independently graded (masked to field assessment) by the field examiner and two other experienced graders. There was only moderate agreement between field assessment and the subsequent photographic evaluations by the three graders. When we counted ungradable photographs as disagreements, mean kappa scores for the signs trachomatous inflammation (follicular [TF]) and trachomatous inflammation (intense [TI]) were 0.44 and 0.51, respectively. There was also only fair-to-moderate agreement between the three assessments (by different examiners) of the photographs. Either the signs TF and TI themselves are not as reliable as previously believed, or photographs should be used for their diagnosis only when reliability testing demonstrates better agreement than found here.
Solomon
Anthony W
AW
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, United Kingdom. anthony.solomon@lshtm.ac.uk
Bowman
Richard J C
RJ
Yorston
David
D
Massae
Patrick A
PA
Safari
Salesia
S
Savage
Brian
B
Alexander
Neal D E
ND
Foster
Allen
A
Mabey
David C W
DC
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008875:Middle Aged; D015588:Observer Variation; D010781:Photography / Q000379:methods*; D013636:Tanzania; D014141:Trachoma / Q000175:diagnosis* / Q000473:pathology