title: Overuse of colonoscopy for colorectal cancer screening and surveillance.
abstract: 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.
  
  
  METHODS
  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.
  
  
  METHODS
  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.
  
  
  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.
authors.affiliation: Division of General Internal Medicine, Massachusetts General Hospital, Boston, MA, USA, gkruse@mgh.harvard.edu.
authors.forename: Gina R
authors.initials: GR
authors.lastname: Kruse
authors.forename: Sami M
authors.initials: SM
authors.lastname: Khan
authors.forename: Alan M
authors.initials: AM
authors.lastname: Zaslavsky
authors.forename: John Z
authors.initials: JZ
authors.lastname: Ayanian
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Sequist
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003111:Colonic Polyps / Q000175:diagnosis / Q000453:epidemiology; D003113:Colonoscopy / Q000592:standards / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology; D055088:Early Detection of Cancer / Q000592:standards / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance / Q000379:methods; D012189:Retrospective Studies; D019564:Unnecessary Procedures / Q000592:standards / Q000706:statistics & numerical data*