Abstract
Purpose :
To assess for the first time the accuracy of a cataract incidence calculator using longitudinal data from the Liwan study. Using simple data such as could be obtained from a RAAB (Rapid Assessment of Avoidable Blindness), this incidence calculator enables service planners to estimate target cataract surgical rates (CSR) needed to eliminate the cataract backlog in their countries, which is crucial for planning.
Methods :
The incidence rate is generally obtained through long-term cohort longitudinal studies, which are often expensive and impractical. A cataract incidence calculator was designed to utilize the data from RAAB, a widely used survey method to model the epidemiology of visually significant cataract and to estimate the incidence of cataract. So far there is no systematic research to test the cataract incidence calculator, the accuracy of its estimation has yet to be determined. In this research, we assessed the accuracy of the cataract incidence calculator using the survey data from a population-based study carried out in Liwan, Southern China. Liwan data has 2003-2004 baseline and a 5-year follow-up (2009) eye-examination results, both includes visual presenting acuity (PVA), best-corrected visual acuity in each eye (if PVA <6/12), lens examination, and the main cause of decreased VA. Using the Liwan baseline data, the incidence calculator estimated the cataract incidence at three different levels of visual acuity (VA<6/18, VA<6/60, VA<3/60) and the results were compared with actual cataract incidence in the follow-up data.
Results :
1061 participants aged 50 and above at baseline were included (male=473, 44.6%; female=588, 55.4%) as input, the estimated five-year annual incidence rate each year from the cataract incidence calculator is 0.0186 [95% CI 0.0137, 0.0228] for VA Level <6/18; 0.0086 [95% CI 0.0058, 0.0123] for VA Level <6/60; and 0.0087 [95% CI 0.0052, 0.0126] for VA Level <3/60. The actual incidence rates for each corresponding level are 0.0140 [95% CI 0.00844, 0.0196]; 0.00700 [95% CI 0.00308, 0.0109] and 0.00680 [95% CI 0.00293, 0.0107] respectively.
Conclusions :
The validation with actual cataract incidence from Liwan data indicates that the incidence calculator is reasonably accurate in the estimation of cataract incidence rate, therefore provides assurance to potential users.
This is a 2020 ARVO Annual Meeting abstract.