title: Longer Withdrawal Time Is Associated With a Reduced Incidence of Interval Cancer After Screening Colonoscopy.
abstract: OBJECTIVE
  Withdrawal times and adenoma detection rates are widely used quality indicators for screening colonoscopy. More rapid withdrawal times have been associated with undetected adenomas, which can increase risk for interval colorectal cancer.
  
  
  METHODS
  We analyzed records of 76,810 screening colonoscopies performed between 2004 and 2009, by 51 gastroenterologists practicing in Minneapolis and St Paul, MN. Colonoscopy records were linked electronically to the state cancer registry (Minnesota Cancer Surveillance System) to identify incident interval cancers that were diagnosed within 5.5 years after the screening examination.
  
  
  RESULTS
  The physicians' mean ± SD withdrawal time was 8.6 ± 1.7 minutes and adenoma detection rates were 25% ± 9%. Longer mean withdrawal times were associated with higher adenoma detection rates (3.6% per minute; 95% confidence interval: 2.4% to 4.8%; P < .0001). We identified 78 cancers during 410,687 person-years of follow-up, for an annual rate of 0.19/1000 person-years. Physicians' mean annual withdrawal times were inversely associated with cancer incidence (P < .0001). Compared with withdrawal times ≥6 minutes, the adjusted incidence rate ratio for withdrawal times of <6 minutes was 2.3 (95% confidence interval: 1.5-3.4; P < .0001).
  
  
  CONCLUSIONS
  Shorter mean annual withdrawal times during screening colonoscopies were independently associated with lower adenoma detection rates and increased risk of interval colorectal cancer.
authors.affiliation: Division of Gastroenterology, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota; Department of Medicine, University of Minnesota School of Medicine, Minneapolis, Minnesota; Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota. Electronic address: Shaukat@umn.edu.
authors.forename: Aasma
authors.initials: A
authors.lastname: Shaukat
authors.affiliation: Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Rector
authors.affiliation: Division of Environmental Health Sciences, School of Public Health, University of Minnesota, Minneapolis, Minnesota.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Church
authors.affiliation: Center for Chronic Disease Outcomes Research, Minneapolis Veterans Affairs Health Care System, Minneapolis, Minnesota.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Lederle
authors.affiliation: Minnesota Gastroenterology P.A., St. Paul, Minnesota.
authors.forename: Adam S
authors.initials: AS
authors.lastname: Kim
authors.affiliation: Minnesota Gastroenterology P.A., St. Paul, Minnesota.
authors.forename: Jeffery M
authors.initials: JM
authors.lastname: Rank
authors.affiliation: Department of Medicine, Yale University School of Medicine, New Haven, Connecticut.
authors.forename: John I
authors.initials: JI
authors.lastname: Allen
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D000368:Aged; D002983:Clinical Competence; D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology / Q000517:prevention & control*; D003113:Colonoscopy / Q000379:methods* / Q000592:standards; D003153:Community Health Services; D055088:Early Detection of Cancer / Q000379:methods* / Q000592:standards; D005260:Female; D006801:Humans; D015994:Incidence; D016018:Least-Squares Analysis; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D016017:Odds Ratio; D010818:Practice Patterns, Physicians'; D011237:Predictive Value of Tests; D065840:Protective Factors; D019984:Quality Indicators, Health Care; D012042:Registries; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
keywords: CRC; Colon Cancer; Early Detection; IRR