title: Factors associated with colonoscopy performed in nonhospital settings.
abstract: BACKGROUND
  Colonoscopy is being increasingly performed in facilities outside of hospitals. Regulation of these facilities is variable, and concerns regarding the quality of procedures in nonhospital (NH) settings have been raised. Further study is needed to better understand endoscopic practice in these facilities.
  
  
  OBJECTIVE
  To describe NH-based colonoscopy practice in Ontario from 1993 to 2005, and to identify patient (age, sex, income quintile and comorbidity) and physician (specialty and colonoscopy volume) factors associated with this practice.
  
  
  METHODS
  The present study was a population-based, cross-sectional analysis using health administrative data from Ontario adults who underwent at least one outpatient colonoscopy between 1993 and 2005. A total of 1,240,781 patients underwent 1,917,714 colonoscopies. The main outcome measure was the receipt of colonoscopy in an NH facility.
  
  
  RESULTS
  An increase in NH-based colonoscopy from 10.0% in 1993 to 15.1% in 2005 (P<0.0001) was found. In the multivariate model, younger, healthier men living in higher income areas were significantly more likely to undergo NH-based colonoscopy. Surgeons and other practitioners (eg, nongastroenterologists and noninternists) were significantly more likely to practice in NH settings. Physicians in the highest colonoscopy volume quintile were 25 times more likely to practice in NH settings than those in the lowest volume quintile (P<0.0001).
  
  
  CONCLUSIONS
  Rates of NH-based colonoscopy are rising in Ontario. High-volume endoscopists and surgeons are most likely to practice in NH settings. Given its increasing use, further study of the practice and the regulation of NH colonoscopy is warranted.
authors.affiliation: Department of Medicine, Division of Gastroenterology, Sunnybrook Health Services Centre, Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Othman
authors.initials: O
authors.lastname: Alharbi
authors.forename: Linda
authors.initials: L
authors.lastname: Rabeneck
authors.forename: Lawrence
authors.initials: L
authors.lastname: Paszat
authors.forename: Duminda N
authors.initials: DN
authors.lastname: Wijeysundera
authors.forename: Rinku
authors.initials: R
authors.lastname: Sutradhar
authors.forename: Lingsong
authors.initials: L
authors.lastname: Yun
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Vinden
authors.forename: Jill
authors.initials: J
authors.lastname: Tinmouth
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000554:Ambulatory Care Facilities / Q000706:statistics & numerical data*; D016009:Chi-Square Distribution; D003113:Colonoscopy / Q000706:statistics & numerical data*; D015897:Comorbidity; D003430:Cross-Sectional Studies; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007182:Income; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008511:Medicine / Q000706:statistics & numerical data; D008875:Middle Aged; D009864:Ontario; D010818:Practice Patterns, Physicians' / Q000706:statistics & numerical data