title: Validity of Teacher-Based Vision Screening and Factors Associated with the Accuracy of Vision Screening in Vietnamese Children.
abstract: OBJECTIVE
  To assess validity of teacher-based vision screening and elicit factors associated with accuracy of vision screening in Vietnam.
  
  
  METHODS
  After brief training, teachers independently measured visual acuity (VA) in 555 children aged 12-15 years in Ba Ria - Vung Tau Province. Teacher VA measurements were compared to those of refractionists. Sensitivity, specificity, positive predictive value and negative predictive value were calculated for uncorrected VA (UVA) and presenting VA (PVA) 20/40 or worse in either eye. Chi-square, Fisher's exact test and multivariate logistic regression were used to assess factors associated with accuracy of vision screening. Level of significance was set at 5%.
  
  
  RESULTS
  Trained teachers in Vietnam demonstrated 86.7% sensitivity, 95.7% specificity, 86.7% positive predictive value and 95.7% negative predictive value in identifying children with visual impairment using the UVA measurement. PVA measurement revealed low accuracy for teachers, which was significantly associated with child's age, sex, spectacle wear and myopic status, but UVA measurement showed no such associations.
  
  
  CONCLUSIONS
  Better accuracy was achieved in measurement of VA and identification of children with visual impairment using UVA measurement compared to PVA. UVA measurement is recommended for teacher-based vision screening programs.
authors.affiliation: a Brien Holden Vision Institute , Public Health Division , Sydney , New South Wales, Australia.
authors.forename: Prakash
authors.initials: P
authors.lastname: Paudel
authors.affiliation: a Brien Holden Vision Institute , Public Health Division , Sydney , New South Wales, Australia.
authors.forename: Vilas
authors.initials: V
authors.lastname: Kovai
authors.affiliation: a Brien Holden Vision Institute , Public Health Division , Sydney , New South Wales, Australia.
authors.forename: Thomas
authors.initials: T
authors.lastname: Naduvilath
authors.affiliation: a Brien Holden Vision Institute , Public Health Division , Sydney , New South Wales, Australia.
authors.forename: Ha Thanh
authors.initials: HT
authors.lastname: Phuong
authors.affiliation: a Brien Holden Vision Institute , Public Health Division , Sydney , New South Wales, Australia.
authors.forename: Suit May
authors.initials: SM
authors.lastname: Ho
authors.affiliation: b Ba Ria - Vung Tau Provincial Eye Centre, BRVT Province , Ba Ria , Vietnam.
authors.forename: Nguyen Viet
authors.initials: NV
authors.lastname: Giap
mesh_terms: D000293:Adolescent; D044466:Asian People / Q000706:statistics & numerical data*; D001766:Blindness / Q000175:diagnosis / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D005139:Eyeglasses / Q000706:statistics & numerical data; D005178:Faculty; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012030:Refractive Errors / Q000175:diagnosis / Q000453:epidemiology; D015203:Reproducibility of Results; D012572:School Health Services; D012680:Sensitivity and Specificity; D014744:Vietnam / Q000453:epidemiology; D015351:Vision Screening / Q000592:standards*; D014792:Visual Acuity / Q000502:physiology*; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*
keywords: Refractive error; school screening; teachers; vision impairment; visual acuity