Volume 91, Issue 3
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



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) ( < 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.


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  1. Thylefors B, Dawson CR, Jones BR, West SK, Taylor HR, , 1987. A simple system for the assessment of trachoma and its complications. Bull World Health Organ 65: 477483. [Google Scholar]
  2. Mariottii SP, , 2003. Proceedings of the 2nd Global Scientific Meeting on Trachoma; Geneva, Switzerland. [Google Scholar]
  3. WHO, 2012. Accelerating Work to Overcome the Global Impact of Neglected Tropical Diseases: A Roadmap for Implementation. Geneva: World Health Organization. [Google Scholar]
  4. Emerson PM, Lindsay SW, Alexander N, Bah M, Dibba SM, Faal HB, Lowe KO, McAdam KP, Ratcliffe AA, Walraven GE, Bailey RL, , 2004. Role of flies and provision of latrines in trachoma control: cluster-randomised controlled trial. Lancet 363: 10931098.[Crossref] [Google Scholar]
  5. Jha H, Chaudary JS, Bhatta R, Miao Y, Osaki-Holm S, Gaynor B, Zegans M, Bird M, Yi E, Holbrook K, Whitcher JP, Lietman T, , 2002. Disappearance of trachoma from Western Nepal. Clin Infect Dis 35: 765768.[Crossref] [Google Scholar]
  6. Michel CE, Roper KG, Divena MA, Lee HH, Taylor HR, , 2011. Correlation of clinical trachoma and infection in Aboriginal communities. PLoS Negl Trop Dis 5: e986.[Crossref] [Google Scholar]
  7. Solomon AW, Harding-Esch E, Alexander ND, Aguirre A, Holland MJ, Bailey RL, Foster A, Mabey DC, Massae PA, Courtright P, Shao JF, , 2008. Two doses of azithromycin to eliminate trachoma in a Tanzanian community. N Engl J Med 358: 18701871.[Crossref] [Google Scholar]
  8. West S, Muñoz B, Lynch M, Kayongoya A, Chilangwa Z, Mmbaga BB, Taylor HR, , 1995. Impact of face-washing on trachoma in Kongwa, Tanzania. Lancet 345: 155158.[Crossref] [Google Scholar]
  9. Schachter J, West SK, Mabey D, Dawson CR, Bobo L, Bailey R, Vitale S, Quinn TC, Sheta A, Sallam S, Mkocha H, Faal H, , 1999. Azithromycin in control of trachoma. Lancet 354: 630635.[Crossref] [Google Scholar]
  10. See CW, Alemayehu W, Melese M, Zhou Z, Porco TC, Shiboski S, Gaynor BD, Eng J, Keenan JD, Lietman TM, , 2011. How reliable are tests for trachoma?–a latent class approach. Invest Ophthalmol Vis Sci 52: 61336137.[Crossref] [Google Scholar]
  11. Amza A, Kadri B, Nassirou B, Stoller NE, Yu SN, Zhou Z, Chin S, West SK, Bailey RL, Mabey DCW, Keenan JD, Porco TC, Lietman TM, Gaynor BD, Partnership for Rapid Elimination of Trachoma (PRET) in Tanzania and The Gambia; , 2012. Community risk factors for ocular chlamydia infection in Niger: pre-treatment results from a cluster-randomized trachoma trial. PLoS Negl Trop Dis 6: e1586.[Crossref] [Google Scholar]
  12. Hassan A, Ngondi JM, King JD, Elshafie BE, Al Ginaid G, Elsanousi M, Abdalla Z, Aziz N, Sankara D, Simms V, Cromwell EA, Emerson PM, Binnawi KH, , 2011. The prevalence of blinding trachoma in northern states of Sudan. PLoS Negl Trop Dis 5: e1027.[Crossref] [Google Scholar]
  13. Solomon AW, Bowman RJ, Yorston D, Massae PA, Safari S, Savage B, Alexander ND, Foster A, Mabey DC, , 2006. Operational evaluation of the use of photographs for grading active trachoma. Am J Trop Med Hyg 74: 505508. [Google Scholar]
  14. Solomon AW, Zondervan M, Kuper H, Buchan JC, Mabey DCW, Foster A, , 2006. Trachoma Control: A Guide for Programme Managers. Geneva: World Health Organization. [Google Scholar]
  15. Gebre T, Ayele B, Zerihun M, Genet A, Stoller NE, Zhou Z, House JI, Yu SN, Ray KJ, Emerson PM, Keenan JD, Porco TC, Lietman TM, Gaynor BD, , 2012. Comparison of annual versus twice-yearly mass azithromycin treatment for hyperendemic trachoma in Ethiopia: a cluster-randomised trial. Lancet 379: 143151.[Crossref] [Google Scholar]
  16. Ayele B, Gebre T, Moncada J, House JI, Stoller NE, Zhou Z, Porco TC, Gaynor BD, Emerson PM, Schachter J, Keenan JD, , 2011. Risk factors for ocular Chlamydia after three mass azithromycin distributions. PLoS Negl Trop Dis 5: e1441.[Crossref] [Google Scholar]
  17. Harding-Esch EM, Edwards T, Mkocha H, Munoz B, Holland MJ, Burr SE, Sillah A, Gaydos CA, Stare D, Mabey DC, Bailey RL, West SK, , 2010. Trachoma prevalence and associated risk factors in the Gambia and Tanzania: baseline results of a cluster randomised controlled trial. PLoS Negl Trop Dis 4: e861.[Crossref] [Google Scholar]
  18. Stare D, Harding-Esch E, Munoz B, Bailey R, Mabey D, Holland M, Gaydos C, West S, , 2011. Design and baseline data of a randomized trial to evaluate coverage and frequency of mass treatment with azithromycin: the Partnership for Rapid Elimination of Trachoma (PRET) in Tanzania and The Gambia. Ophthalmic Epidemiol 18: 2029.[Crossref] [Google Scholar]
  19. Murphy AH, , 1996. General decomposition of MSE-based skill scores: measures of some basic aspects of forecast quality. Am Meteorological Soc 124: 23532369. [Google Scholar]
  20. Roper KG, Taylor HR, , 2009. Comparison of clinical and photographic assessment of trachoma. Br J Ophthalmol 93: 811814.[Crossref] [Google Scholar]
  21. West SK, Taylor HR, , 1990. Reliability of photographs for grading trachoma in field studies. Br J Ophthalmol 74: 1213.[Crossref] [Google Scholar]
  22. Bhosai SJ, Amza A, Beido N, Bailey RL, Keenan JD, Gaynor BD, Lietman TM, , 2012. Application of smartphone cameras for detecting clinically active trachoma. Br J Ophthalmol 96: 13501351.[Crossref] [Google Scholar]

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  • Received : 12 Nov 2013
  • Accepted : 31 Jan 2014
  • Published online : 03 Sep 2014

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