T2042 Medicare Reimbursement Changes Are Associated with Increments in First Time Colonoscopy and Polypectomy

Abstract

Background: Cross-sectional studies have reported an increase in annual colonoscopy volume associated with changes in Medicare reimbursement policies for colon cancer screening and surveillance. It is not known how much of the increment reflected initial versus follow up procedures and if the increase was associated with significant changes in polyp removal. Methods: Using a 5% sample of 1991-2002 Medicare claims data from cancer-free, fee-forservice beneficiaries aged 65 and older, the annual rate of first time colonoscopy procedures under Medicare was calculated. Procedures were divided into those that were diagnostic or included biopsy only (diagnostic), and those that included a code for snare polypectomy, hot biopsy or ablation (polypectomy). We compared the rates of diagnostic and polypectomy procedures by calendar year as well as between periods of Medicare reimbursement for screening: none (1991-1997), increased risk only (1998-6/01), and universal (7/01-2002). The proportion of all examinations with polypectomy was also compared between time periods in a multivariable model adjusting for demographic factors. Results: Annual rates for initial diagnostic colonoscopy and polypectomy are shown in the Table. The average annual rate of diagnostic procedures increased from 1.25% (1991-1997) to 1.42% (19982000) to 2.03% (2001-2002) and the annual rates of polypectomy increased from 0.17% to 0.20% to 0.32%, respectively. In multivariable analysis, there was a significant increase in the proportion of procedures associated with polypectomy in both 1998-6/01 (OR 1.07, 95% CI 1.02-1.14) and 7/01-2002 (OR 1.18, 95% CI 1.11-1.26). Conclusions: In this population-based sample, changes in colonoscopy reimbursement under Medicare were associated with increments in the volume of first-time colonoscopies and polypectomies. The increase in the proportion of procedures with polypectomy suggests that these policies may account in part for observed declines in colon cancer incidence and mortality in the U.S.