Trends in glaucoma surgery incidence and reimbursement for physician services in the Medicare population from 1995 to 1998

Objective: To better understand the relationship between glaucoma management and economic incentives, we examined the volume and the reimbursement of argon laser trabeculoplasty (ALT) and trabeculectomy in a 5% random sample of the Medicare population from 1995 to 1998. Design: Retrospective cohort study. Participants: Subjects in a 5% random sample of the Medicare population who had ALT and trabeculectomy from 1995 to 1998. Methods: Using the Health Care Financing Administration (HCFA) Physician/Supplier Part-B files for a 5% random sample of the Medicare population, we identified all subjects who had ALT and trabeculectomy from 1995 to 1998. Descriptive summaries (the number of surgeries and the mean and the standard deviation of reimbursement per surgery) were calculated for each year. Analysis of variance was used to test for differences in reimbursement per surgery across years. Chi-square tests were used to assess any associations between the changing numbers of ALTs and trabeculectomies over the study period and both age and race. Main Outcome Measures: We assessed the number of ALTs and trabeculectomies and the allowed charges for each surgery in the 5% random sample of the Medicare population from 1995 to 1998. Results: The volume of both ALTs and trabeculectomies declined during the study period. Reimbursement per surgery for both ALT and trabeculectomy varied significantly across years (P < 0.001). Significant associations were found between the changing number of ALTs and both age and race. Conclusions: Changing numbers of ALT and trabeculectomy seem unrelated to reimbursement rates. Rather, these changes are more likely driven by new developments in the clinical management of glaucoma, among other factors.