Applicability of the Smart Vision Screening Instrument among Chinese Primary School Students

Background: A smart vision screening instrument was applied for screening low eyesight in primary school stu-dents in Wuhan, China. We aimed to compare the differences in test results between this instrument and lamp-box visual acuity charts, assess the validity of the screening results, and perform a preliminary comparison of the cost inputs of the two approaches. Methods: In this cross-sectional study conducted in Wuhan, China in 2017, vision tests were performed on the same day among enrolled primary school students by using the two approaches. The t-test and kappa test were per-formed to compare the differences, and the indicators of validity were calculated and receiver operating characteris-tic (ROC) curves were drawn. Existing cost-input data were collected and the budget was analyzed. Results: In total, 1001 schoolchildren were included, and the prevalence of low eyesight was 21.18% (95% CI: 18.71-23.87%). The test results of the two approaches were not statistically different (t=1.929, P>0.05) and showed moderate consistency (kappa=0.519, P<0.001). Sensitivity and specificity of the instrument were 84.90% (95% CI: 79.21-89.30%) and 91.63% (95% CI: 89.42-91.64%), respectively; positive predictive value was 73.17% (95% CI: 67.10-78.51%); and negative predictive value was 95.76% (95% CI: 94.00-97.04%). Area under the ROC curve was 0.883 (95% CI: 0.853-0.913) and significantly differed from 0.5 (P<0.001). The budget when using the instrument decreased 48.07% compared to that when using lamp-box visual acuity charts. Conclusion: The test result of the instrument is reliable, and using it to conduct screening is cost-saving. Therefore, it might be popularized for vision monitoring in schoolchildren.