title: Endoscopist specialty is associated with incident colorectal cancer after a negative colonoscopy.
abstract: OBJECTIVE
  The incidence of colorectal cancer (CRC) is reduced for at least 10 years after a negative colonoscopy, compared with the general population. However, CRCs do occur in individuals after a negative colonoscopy. We investigated whether the colonoscopy volume and specialty of the endoscopists who perform the exam are associated with CRC after a negative complete colonoscopy.
  
  
  METHODS
  A cohort of Ontario residents, 50-80 years old, who had a negative complete colonoscopy between January 1, 1992, and December 31, 1997, was identified by using linked administrative databases. Cohort members had no history of CRC or inflammatory bowel disease or a recent colonic resection. Each individual was followed through December 31, 2006, and those with a new diagnosis of CRC were identified. Multivariable analysis was used to evaluate the association of patient, endoscopist, and procedure setting characteristics with incident CRC.
  
  
  RESULTS
  A cohort of 110,402 individuals with a negative complete colonoscopy was identified; the majority (86%) had their procedures performed in hospitals. During the 15-year follow-up period, 1596 (14.5%) developed CRC. There was no association between endoscopist colonoscopy volume and incident CRC. Among persons who had their colonoscopies at a hospital, those who had their procedures performed by a non-gastroenterologist were at significantly increased risk for developing subsequent CRC.
  
  
  CONCLUSIONS
  Endoscopist specialty is an important determinant of the effectiveness of colonoscopy in usual clinical practice. After a negative colonoscopy, those who have had their procedures performed by a gastroenterologist are less likely to develop CRC.
authors.affiliation: Department of Medicine, University of Toronto, Toronto, Ontario, Canada. linda.rabeneck@sunnybrook.ca
authors.forename: Linda
authors.initials: L
authors.lastname: Rabeneck
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Paszat
authors.forename: Refik
authors.initials: R
authors.lastname: Saskin
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology*; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology; D011361:Professional Competence / Q000706:statistics & numerical data