Use of surveillance colonoscopy in medicare patients with inflammatory bowel disease prior to colorectal cancer diagnosis

Background: Patients with longstanding inflammatory bowel disease (IBD) involving large intestine proximal to rectum are considered to be at increased risk for colorectal cancer (CRC). One prior study showed low utilization of surveillance colonoscopy in patients with ≥8 years of ulcerative colitis (UC) in the USA. Aims: To study use of surveillance colonoscopy among Medicare beneficiaries with IBD in the 2-year period prior to CRC diagnosis. Data and Methods: Our study sample included Medicare beneficiaries in the SEER-Medicare-linked database who were diagnosed with CRC during 2001-2005 and had ≥3 physician visits with ICD-9 diagnosis code for IBD prior to CRC diagnosis. Medicare beneficiaries aged >85 years without Part B coverage or enrolled in HMOs were excluded. Colonoscopy performed within 6-30 months prior to CRC diagnosis was defined as surveillance colonoscopy. The χ² test and multivariate logistic regression were used in statistical analysis. Results: Of 241 Medicare beneficiaries with IBD and diagnosed with CRC, 92 (38%) patients underwent ≥1 surveillance colonoscopy in the 2 years prior to cancer diagnosis. The use of surveillance colonoscopy was similar between Crohn's disease (28/86, 33%) and UC (64/155, 41%). In multivariate logistic regression, older age (odds ratio (OR) 0.97, 95% confidence interval (CI) 0.94-0.99) was negative associated with surveillance colonoscopy use and personal history of colon polyp (OR 2.73, 95% CI 1.09-6.87) was positively associated with surveillance colonoscopy use. Conclusions: Use of surveillance colonoscopy was low among Medicare beneficiaries with IBD in the 2 years prior to CRC diagnosis.