Use of colonoscopy for polyp surveillance in Medicare beneficiaries

Abstract

Background: Professional society guidelines recommend follow-up colonoscopy for patients with resected colonic adenomas. However, adherence to guideline recommendations in routine clinical practice has not been well characterized.

Methods: The authors used a population-based sample of Medicare beneficiaries to identify all patients aged ≥70 years who had a claim for colonoscopy with polypectomy or hot biopsy during the period from 2001 to 2004. Medicare claims through 2009 identified colonoscopy within the following 5 years as well as fecal occult blood testing, sigmoidoscopy, and barium enema.

Results: In total, 12,771 patients were included. At 5 years, 45.7% of patients underwent another colonoscopy, and 32.3% of procedures included a polypectomy. The rates of fecal occult blood testing, flexible sigmoidoscopy, and barium enema at 5 years were 54%, 3.8%, and 2.9%, respectively. There was a marked decrease in repeat colonoscopy at 1 year, 3 years, and 5 years with more recent years of index procedures. Other predictors of undergoing repeat colonoscopy were younger age, African American race, and a colonoscopy before the index examination. There was no association with physician specialty. The decreasing use of colonoscopy with time was maintained in a multivariable analysis.

Conclusions: In a sample of elderly Medicare beneficiaries, there was under use of follow-up colonoscopy at 5 years after polypectomy, and <50% of patients received a repeat examination. In particular, the use of this procedure decreased over the 4-year study period. Coupled with other data indicating the overuse of follow-up colonoscopy in patients without polyps, there appeared to be significant discordance between guidelines and actual practice.

Figure 1

Kaplan-Meier curve showing the proportion of patients with previous polypectomy undergoing repeat colonoscopy in follow up stratified by the presence or absence of previous risk factors for neoplasia (prior polyp, family history of colon cancer). There was a significantly greater use of colonoscopy in patients with risk factors (p<0.0001).

Figure 2

Kaplan-Meier curves of the receipt of repeat colonoscopy following polypectomy stratified by year of index polypectomy. The frequency decreased with later years of the index colonoscopy (p<0.0001).