Assessment of the validity and reliability of the Simplified Visual Acuity Chart when administered to adults 65 years of age and older

Objective: An enormous potential exists for use of the Simplified Visual Acuity Card (SVAC) in conducting mass eye screening because it can be easily utilized in the field. The purpose of the current study was to compare the SVAC with Snellen's chart in a sample of adults > 65 years of age. Methods: Thirty-eight elderly adults attending one of two Hsin-Chu County primary health centers in March 2005 volunteered to participate in the study. The SVAC and Snellen's chart were simultaneously administered to the participants, and the SVAC was administered again one week later. The accuracy, sensitivity, specificity, and Kappa coefficient of the SVAC were calculated to assess SVAC validity and reliability. Results: Based on SVAC testing, the prevalence of visual acuity in the study population was determined to be 52.6%, 50.0%, and 42.1% for the left eye, right eye, and both eyes, respectively, consistent with corresponding accuracy rates of 0.82, 0.84, and 0.82, sensitivities of 1.00, 0.93, and 0.91, and specificities of 0.72, 0.78, and 0.78. On the basis of the SVAC test-retest data, the Kappa coefficient was estimated to be 0.79, 0.74, and 0.73 for the left eye, right eye, and both eyes, respectively. Conclusions: The test-retest reliability for the SVAC was satisfactory; however, the prevalence of visual impairment estimated using the SVAC in elderly adults was higher than when tested with Snellen's chart.