Socioeconomic and rural differences for cataract surgery in Western Australia

Abstract

Background: To examine the relationship between socioeconomic factors, residential locality and cataract surgery incidence. Methods: This was a population-based study using the Western Australian Data Linkage System to identify all cataract operations performed in patients aged 50+ years in 1996 and 2001. Patients'residential addresses at the time of operation were geocoded to census localities. Using census-derived indices, procedures were categorized into socioeconomic groups and residential locations (metropolitan and rural). Poisson regression was used to analyse for differences in procedure rates. Results: The crude cataract surgery rate in Western Australia increased from 4458 to 6631 procedures per million person-years between 1996 and 2001. Female and older patients underwent more surgery. Metropolitan residents were more likely to undergo surgery compared with rural residents; a difference that increased by 17% between 1996 and 2001 (1996: incidence rate ratio [IRR]1.07, 95% confidence interval [CI]1.02-1.13; 2001: IRR 1.24, 95% CI 1.18-1.29). A pronounced 'U-shaped' pattern of difference had developed for socioeconomic disadvantage by 2001. The most advantaged underwent 9% more surgery than the most disadvantaged. Rates in the middle two groups were less than the lowest one. Conclusion: There was growing inequity in the rates of cataract surgery for rural and poorer patients between 1996 and 2001. These differences partly reflect the increasingly two-tiered Australian health system with more privately provided cataract surgery in urban areas. © 2006 Royal Australian and New Zealand College of Ophthalmologists.