The goal of this study was to evaluate the effect of demographic, environmental and provider-related factors on the probability of receiving cataract surgery among Medicare beneficiaries. The authors were concerned with both regional level variables (such as the proportion of blacks in an area) and individual level variables (such as the race of each patient).

The variation in cataract surgery across different geographic areas observed in this analysis was low compared with the geographic variation in provision of other surgical procedures. However, the regional-level analysis did show that geographic latitude, the number of optometrists in the area, and the allowed charge for the area were significantly associated with the rate of cataract surgery in the area. The individual-level analysis showed that age, gender, race, and practice expense were significantly associated with odds of cataract surgery, in addition to the variables that were significant in the regional analysis.

With regard to race specifically, white beneficiaries were 27% (95% confidence interval=23% to 31%) more likely than black beneficiaries to undergo cataract surgery. The authors argued that this suggests that black Medicare beneficiaries with cataracts may be undertreated and emphasized that this finding "is concerning, particularly in light of existing data that blindness from unoperated cataract is four times more common among black Americans than among their white counterparts."