title: Can information on the purpose of spectacle use and age at first use predict refractive error type?
abstract: OBJECTIVE
  To assess the sensitivity and specificity of predicting refractive error type using information from a four-item questionnaire on the purpose of spectacle use and age at first use.
  
  
  METHODS
  The Sydney Myopia Study examined 1,740 year 1 (78.9% response) and 2,353 year 7 students (75.3% response) from a random cluster sample of 34 primary and 21 secondary schools across Sydney. Parents of participants completed a four-item questionnaire that sought data on parental spectacle use, age at first use, and purpose of use (for clear distant vision, close work, or both). Prescriptions were obtained for 720 of 3,209 (22%) parents (73% of those approached) for validation. A receiver operating characteristic (ROC) curve was used to determine the optimal cutoff age for spectacle use in myopia classification.
  
  
  RESULTS
  Using the ROC curve, a cutoff age of 30 years at first spectacle use produced the highest accuracy in determining myopia. We combined information on the purpose for using spectacles (for distant and near vision) and age of first use at 30 years or younger to determine myopia, otherwise hyperopia. Validated against prescriptions, the sensitivity and specificity of these predictions were 0.89 and 0.83, respectively, for myopia. The specificity was 0.92 for hyperopia and 0.80 for astigmatism, though corresponding sensitivities were lower at 0.23 and 0.46, respectively.
  
  
  CONCLUSIONS
  In a sample of the parents of Sydney Myopia Study participants, information on the purpose of spectacle use with an age-at-first-use criterion can identify myopic refractive error with reasonable sensitivity and specificity. This four-item questionnaire may assist future epidemiological studies of screening for myopia.
authors.affiliation: Department of Ophthalmology (Centre for Vision Research, Westmead Hospital) and the Westmead Millennium Institute, Westmead, Australia.
authors.forename: Jenny
authors.initials: J
authors.lastname: Ip
authors.forename: Dana
authors.initials: D
authors.lastname: Robaei
authors.forename: Elena
authors.initials: E
authors.lastname: Rochtchina
authors.forename: Kathryn
authors.initials: K
authors.lastname: Rose
authors.forename: Wayne
authors.initials: W
authors.lastname: Smith
authors.forename: Jie Jin
authors.initials: JJ
authors.lastname: Wang
authors.forename: Paul
authors.initials: P
authors.lastname: Mitchell
mesh_terms: D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000145:classification* / Q000175:diagnosis; D002648:Child; D003430:Cross-Sectional Studies; D005139:Eyeglasses / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000145:classification* / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000145:classification* / Q000175:diagnosis; D009517:New South Wales / Q000453:epidemiology; D010290:Parents; D011237:Predictive Value of Tests; D055656:Prescriptions / Q000706:statistics & numerical data; D012372:ROC Curve; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D011795:Surveys and Questionnaires