title: A population-based analysis of outpatient colonoscopy in adults assisted by an anesthesiologist.
abstract: BACKGROUND
  The use of propofol to sedate patients for colonoscopy, generally administered by an anesthesiologist in North America, is increasingly popular. In the United States, regional use of anesthesiologist-assisted endoscopy appears to correlate with local payor policy. This study's objective was to identify nonpayor factors (patient, physician, institution) associated with anesthesiologist assistance at colonoscopy.
  
  
  METHODS
  The authors performed a population-based cross-sectional analysis using Ontario health administrative data, 1993-2005. All outpatient colonoscopies performed on adults were identified. Hierarchical multivariable modeling was used to identify patient (age, sex, income quintile, comorbidity), physician (specialty, colonoscopy volume), and institution (type, volume) factors associated with receipt of anesthesiologist-assisted colonoscopy.
  
  
  RESULTS
  During the study period, 1,838,879 colonoscopies were performed on 1,202,548 patients. The proportion of anesthesiologist-assisted colonoscopies rose from 8.4% in 1993 to 19.1% in 2005 (P < 0.0001). In the hierarchical model, patients in low-volume community hospitals were five times more likely to receive anesthesiologist-assisted colonoscopy than patients in high-volume community hospitals (odds ration 4.9; 95% confidence interval 4.4-5.5). Less than 1% of colonoscopies in academic hospitals were anesthesiologist-assisted. Compared to gastroenterologists, surgeons were more likely to perform anesthesiologist-associated colonoscopy (odds ratio 1.7; 95% confidence interval 1.1-2.6).
  
  
  CONCLUSIONS
  In Ontario, rates of anesthesiologist-assisted colonoscopy have risen dramatically. Institution type was most strongly associated with this practice. Further investigation is needed to determine the most appropriate criteria for the use of anesthesiology services during colonoscopy.
authors.affiliation: Department of Medicine, Division of Gastroenterology, University of Toronto, Sunnybrook Health Sciences Centre, 2075 Bayview Ave.,Toronto, Ontario, Canada.
authors.forename: Othman
authors.initials: O
authors.lastname: Alharbi
authors.forename: Linda
authors.initials: L
authors.lastname: Rabeneck
authors.forename: Lawrence F
authors.initials: LF
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: D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D015331:Cohort Studies; D003113:Colonoscopy; D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009313:National Health Programs; D009864:Ontario; D010045:Outpatients; D010820:Physicians; D011153:Population; D012189:Retrospective Studies; D012959:Socioeconomic Factors; D055815:Young Adult