Colon polyp recurrence in a managed care population.

BACKGROUND Detection, treatment, and subsequent screening of patients with colorectal polyps have considerable implications for public health. Understanding the natural history of colorectal polyps from biologic and health care services standpoints is critical in determining optimal treatment. METHODS Using computerized data from a large Midwestern health maintenance organization, we identified patients 50 years or older who underwent a polypectomy (index polypectomy) between January 1, 1989, and December 31, 1999. We followed up patients to identify subsequent polypectomies through September 1, 2001. RESULTS Our final study sample consisted of 8865 individuals with an index polypectomy. Overall, 2704 patients (30.5%) were diagnosed as having recurrent polyps. Kaplan-Meier projections estimate that 50% of patients will have a recurrence within 7.6 years (95% confidence interval [CI], 7.2-8.1 years). Among patients who underwent colon screening at least 9 months after the index polypectomy (52% of original cohort), Kaplan-Meier projections estimate that 50% will have a recurrent polyp within 3.9 years (95% CI, 3.8-4.1 years). CONCLUSIONS The results demonstrate that, even when screening and treatment are received by those who need it, the risk of colon polyp recurrence is high and many patients do not undergo additional screening. Efforts to increase and monitor ongoing screening of postpolypectomy patients are warranted. In addition, further research is needed to better identify patients at risk for recurrence so that continued screening and other interventions can be targeted at these groups.