Background: Ongoing efforts to increase colorectal cancer (CRC) screening rates have raised concerns that these exams may be overused, thereby subjecting patients to unnecessary risks and wasting healthcare resources.
Objective: Our aim was to measure overuse of screening and surveillance colonoscopies among average-risk adults, and to identify correlates of overuse.
Design, setting, and participants: Our approach was a retrospective cohort study using electronic health record data for patients 50-65 years old with no personal history of CRC or colorectal adenomas with an incident CRC screening colonoscopy from 2001 to 2010 within a multispecialty physician group practice.
Main outcome measures: We measured time to next screening or surveillance colonoscopy and predictors of overuse (exam performed more than one year earlier than guideline recommended intervals) of colonoscopies.
Key results: We identified 1,429 adults who had an incident colonoscopy between 2001 and 2010, and they underwent an additional 871 screening or surveillance colonoscopies during a median follow-up of 6 years. Most follow-up screening colonoscopies (88%) and many surveillance colonoscopies (49%) repeated during the study represented overuse. Time to next colonoscopy after incident screening varied by exam findings (no polyp: median 6.9 years, interquartile range [IQR]: 5.1-10.0; hyperplastic polyp: 5.7 years, IQR: 4.9-9.7; low-risk adenoma: 5.1 years, IQR: 3.3-6.3; high-risk adenoma: 2.9 years, IQR: 2.0-3.4, p < 0.001). In logistic regression models of colonoscopy overuse, an endoscopist recommendation for early follow-up was strongly associated with overuse of screening colonoscopy (OR 6.27, 95% CI: 3.15-12.50) and surveillance colonoscopy (OR 13.47, 95% CI 6.61-27.46). In a multilevel logistic regression model, variation in the overuse of screening colonoscopy was significantly associated with the endoscopist performing the previous exam.
Conclusions: Overuse of screening and surveillance exams are common and should be monitored by healthcare systems. Variations in endoscopist recommendations represent targets for interventions to reduce overuse.