Prevalence Estimation of Cataract based on a Screening Test

ABSTRACT

PURPOSE: To estimate the prevalence of cataracts based on screening test results and statistical estimation methods. METHODS: Between June 1994 and September 2005, 85,505 persons aged 20 years and older were screened at a health promotion center for a general health care screen. We assumed that all subjects had complete screening results; however some subjects had an unknown disease status. A 2x3 table form could be generated from this data set. To estimate cataract prevalence, we used a maximum likelihood estimation method to reconstruct a 2x2 table including probabilities for each cell. RESULTS: The overall estimated cataract prevalence was 13.98% (95% confidence intervals, 13.75% to 14.21%). We estimated the prevalence of cataracts to be 15.29% in men (95% confidence intervals, 14.95% to 15.63%) and 12.97% in women (95% confidence intervals, 12.65% to 13.29%). In addition, we found that the cataract prevalence distinctly increased in people aged 60 years or older. CONCLUSIONS: We found that these estimated cataract prevalences were not considerably different from study results obtained in other countries. Therefore, our method may be considered to be appropriate for estimating prevalence. Our results indicate that cataract prevalence in our study population increases with age and highlight the need for early detection and early interventions.