© 1989 Oxford University Press
research-article |
Validation of a Self-Report Inventory for the Measurement of Visual Acuity
Department of Psychology, University of British Columbia 2136 West Mall, Vancouver, BC, Canada, V6T 1W5.
Coren S (Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver BC, Canada V6T 1W5) and Hakstian A R. Validation of a self-report inventory for the measurement of visual acuity. International Journal of Epidemiology 1989, 18: 451456.
Previous attempts to assess visual acuity via self-report survey items have shown low sensitivity. This may be due to use of dichotomous response formats, too few items, and reliance upon face valid, rather than laboratory-validated items. On the basis of a preliminary sample of 164 individuals, we developed a self-report inventory, suitable for group testing or survey administration. The inventory was then validated against laboratory measures of acuity in a separate sample of 570 subjects. The resulting, brief, ten-item scale was shown to be a reliable and valid predictor of visual acuity. Conversion tables were developed which allow scale totals to be used to predict Snellen acuity. For 91% of the sample, the inventory predicts objectively measured acuity within plus or minus one Snellen line. A copy of the inventory and scoring procedure is appended to this report.
Received 1 November 1988