Underuse and Overuse of Colonoscopy for Repeat Screening and Surveillance in the Veterans Health Administration

Background & Aims: Regular screening with colonoscopy lowers colorectal cancer incidence and mortality. We aimed to determine patterns of repeat and surveillance colonoscopy and identify factors associated with overuse and underuse of colonoscopy. Methods: We analyzed data from participants in a previous Veterans Health Administration (VHA) study who underwent outpatient colonoscopy at 25 VHA facilities between October 2007 and September 2008 (n = 1455). The proportion of patients who received a follow-up colonoscopy was calculated for 3 risk groups, which were defined on the basis of the index colonoscopy: no adenoma, low-risk adenoma, or high-risk adenoma. Results: Colonoscopy was overused (used more frequently than intervals recommended by guidelines) by 16% of patients with no adenomas, 26% with low-risk adenomas, and 29% with high-risk adenomas. Most patients with high-risk adenomas (54%) underwent colonoscopy after the recommended interval or did not undergo colonoscopy. Patients who received a follow-up recommendation that was discordant with guidelines were more likely to undergo colonoscopy too early (no adenoma odds ratio [OR], 3.80; 95% confidence interval [CI], 2.31-6.25 and low-risk adenoma OR, 5.28; 95% CI, 1.88-14.83). Receipt of colonoscopy at nonacademic facilities was associated with overuse among patients without adenomas (OR, 5.26; 95% CI, 1.96-14.29) or with low-risk adenomas (OR, 3.45; 95% CI, 1.52-7.69). Performance of colonoscopies by general surgeons vs gastroenterologists (OR, 2.08; 95% CI, 1.02-4.23) and female sex of the patient (OR, 3.28; 95% CI, 1.06-10.16) were associated with overuse of colonoscopy for patients with low-risk adenomas. No factors examined were associated with underuse of colonoscopy among patients with high-risk adenomas. Conclusions: In an analysis of patients in the VHA system, more than one fourth of patients with low-risk adenomas received follow-up colonoscopies too early, whereas more than one half of those with high-risk adenomas did not undergo surveillance colonoscopy as recommended. Our findings highlight the need for system-level improvements to facilitate the appropriate delivery of colonoscopy that is based on individual risk.