Geographic variation in cumulative incidence of private cataract surgery in Australia and its influencing factors: Findings from the 45 and Up Study

Purpose: To investigate the geographic variation in the cumulative incidence of private cataract surgery (PCS) and its association with remoteness, socioeconomic, and private health insurance coverage indexes in a large Australian population. Methods: A prospective population-based study of 266,896 Australian adults living in New South Wales (NSW) aged 45 years older and over were enrolled in the 45 and Up Study. PCS was identified using Medicare claims data. Participants were assigned to a Statistical Area Level 3 (SA3) based on residential postcode in NSW. Cumulative incidence of PCS (number of surgery per 100,000 population from 2006 to 2016) among 89 SA3s was calculated and standardized to the baseline population. Remoteness and socioeconomic deprivation was derived from Australian Bureau of Statistics (ABS). Private health insurance coverage rates were obtained from the baseline interview. Results: A total of 257,237 participants with complete data were included in the current analysis. During the study period, a total of 67,707 cataract surgeries were performed among 39,744 participants. Cumulative incidence of PCS varied from 14,897 to 37,314 per 100,000 across 89 SA3s. Multivariable adjusted regression models showed that remoteness index and private health insurance coverage rates were independently associated with cumulative incidence of PCS (all P < 0.05), while no significant association between socioeconomic deprivation and cumulative incidence of PCS was observed. Collectively, these three variables explained 52.7% of the geographic variability. Conclusions: The geographical variation in the cumulative incidence of PCS calls for interventions targeted at individuals living in remote areas to reduce the burden of cataract-related vision impairment.