Evaluation and model to achieve sex parity in cataract surgical coverage in Theni district, India

Background/aims To propose an approach to determine the target ratio of cataract surgical rates (CSRs) of female to male subpopulations to increase sex parity in cataract surgical coverage (CSC), based on the sex gap in cataract burden and incidence, and demonstrate its application to Theni district, India. Methods A population-based longitudinal study between January 2016 and April 2018. We recruited 24327 participants using random cluster sampling. We conducted detailed eye examinations of 7087 participants aged >= 40 years (4098 females, 2989 males). We fit exponential models to the age-specific and sex-specific cataract burden and estimated annual incidence rates. We developed a spreadsheet-based planning tool to compute the target CSR ratio of female to male subpopulations. Results Among those aged >= 40 years, cataract burden was 21.4% for females and 17.5% for males (p<0.05). CSC was 73.9% for females versus 78.6% for males (p<0.05), with an effective CSC of 52.6% for females versus 57.6% for males (p<0.05). Treating only incident cataracts each year requires a target CSR ratio of female to male subpopulations of 1.30, while addressing in addition 10% of the coverage backlog for females and 5% for males requires a target CSR ratio of 1.48. Conclusions The female population in Theni district, as in many low-income and middle-income countries, bears a higher cataract burden and lower CSC. To enhance sex parity in coverage, both the higher number of annual incident cataracts and the larger backlog in females will need to be addressed.