title: Population-Based Colonoscopy Screening for Colorectal Cancer: A Randomized Clinical Trial.
abstract: Although some countries have implemented widespread colonoscopy screening, most European countries have not introduced it because of uncertainty regarding participation rates, procedure-related pain and discomfort, endoscopist performance, and effectiveness. To our knowledge, no randomized trials on colonoscopy screening currently exist.
  
  
  
  To investigate participation rate, adenoma yield, performance, and adverse events of population-based colonoscopy screening in several European countries.
  
  
  
  A population-based randomized clinical trial was conducted among 94 959 men and women aged 55 to 64 years of average risk for colon cancer in Poland, Norway, the Netherlands, and Sweden from June 8, 2009, to June 23, 2014.
  
  
  
  Colonoscopy screening or no screening.
  
  
  
  Participation in colonoscopy screening, cancer and adenoma yield, and participant experience. Study outcomes were compared by country and endoscopist.
  
  
  
  Of 31 420 eligible participants randomized to the colonoscopy group, 12 574 (40.0%) underwent screening. Participation rates were 60.7% in Norway (5354 of 8816), 39.8% in Sweden (486 of 1222), 33.0% in Poland (6004 of 18 188), and 22.9% in the Netherlands (730 of 3194) (P < .001). The cecum intubation rate was 97.2% (12 217 of 12 574), with 9726 participants (77.4%) not receiving sedation. Of the 12 574 participants undergoing colonoscopy screening, we observed 1 perforation (0.01%), 2 postpolypectomy serosal burns (0.02%), and 18 cases of bleeding owing to polypectomy (0.14%). Sixty-two individuals (0.5%) were diagnosed with colorectal cancer and 3861 (30.7%) had adenomas, of which 1304 (10.4%) were high-risk adenomas. Detection rates were similar in the proximal and distal colon. Performance differed significantly between endoscopists; recommended benchmarks for cecal intubation (95%) and adenoma detection (25%) were not met by 6 (17.1%) and 10 of 35 endoscopists (28.6%), respectively. Moderate or severe abdominal pain after colonoscopy was reported by 601 of 3611 participants (16.7%) examined with standard air insufflation vs 214 of 5144 participants (4.2%) examined with carbon dioxide (CO2) insufflation (P < .001).
  
  
  
  Colonoscopy screening entails high detection rates in the proximal and distal colon. Participation rates and endoscopist performance vary significantly. Postprocedure abdominal pain is common with standard air insufflation and can be significantly reduced by using CO2.
  
  
  
  clinicaltrials.gov Identifier: NCT00883792.
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway2Department of Transplantation Medicine and KG Jebsen Center for Colorectal Cancer Research, Oslo University Hospital, Oslo, Norway 3Department of Epidemiology, Harvard T.
authors.forename: Michael
authors.initials: M
authors.lastname: Bretthauer
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway4Department of Gastroenterological Oncology, The Maria Sklodowska Curie Memorial Cancer Center and Institute of Oncology and Medical Center for Postgraduate Education, War.
authors.forename: Michal F
authors.initials: MF
authors.lastname: Kaminski
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway2Department of Transplantation Medicine and KG Jebsen Center for Colorectal Cancer Research, Oslo University Hospital, Oslo, Norway.
authors.forename: Magnus
authors.initials: M
authors.lastname: Løberg
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan Kettering Cancer Center, New York, NY.
authors.forename: Ann G
authors.initials: AG
authors.lastname: Zauber
authors.affiliation: Department of Gastroenterological Oncology, The Maria Sklodowska Curie Memorial Cancer Center and Institute of Oncology and Medical Center for Postgraduate Education, Warsaw, Poland.
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Regula
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Kuipers
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA7Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA8Division of Health Sciences and Technology, Harvard-Massachusetts Institute of Technology.
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Hernán
authors.affiliation: Frontier Science Scotland, Kincraig, UK.
authors.forename: Eleanor
authors.initials: E
authors.lastname: McFadden
authors.affiliation: Frontier Science Scotland, Kincraig, UK.
authors.forename: Annike
authors.initials: A
authors.lastname: Sunde
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway2Department of Transplantation Medicine and KG Jebsen Center for Colorectal Cancer Research, Oslo University Hospital, Oslo, Norway 3Department of Epidemiology, Harvard T.
authors.forename: Mette
authors.initials: M
authors.lastname: Kalager
authors.affiliation: Department of Gastroenterology and Hepatology, Academic Medical Centre, Amsterdam, the Netherlands.
authors.forename: Evelien
authors.initials: E
authors.lastname: Dekker
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Iris
authors.initials: I
authors.lastname: Lansdorp-Vogelaar
authors.affiliation: Department of Transplantation Medicine and KG Jebsen Center for Colorectal Cancer Research, Oslo University Hospital, Oslo, Norway.
authors.forename: Kjetil
authors.initials: K
authors.lastname: Garborg
authors.affiliation: Department of Gastroenterological Oncology, The Maria Sklodowska Curie Memorial Cancer Center and Institute of Oncology and Medical Center for Postgraduate Education, Warsaw, Poland.
authors.forename: Maciej
authors.initials: M
authors.lastname: Rupinski
authors.affiliation: Department of Gastroenterology and Hepatology, Erasmus Medical Centre, Rotterdam, the Netherlands.
authors.forename: Manon C W
authors.initials: MC
authors.lastname: Spaander
authors.affiliation: Department of Gastroenterological Oncology, The Maria Sklodowska Curie Memorial Cancer Center and Institute of Oncology and Medical Center for Postgraduate Education, Warsaw, Poland.
authors.forename: Marek
authors.initials: M
authors.lastname: Bugajski
authors.affiliation: Department of Medicine, Sørlandet Hospital, Arendal, Norway.
authors.forename: Ole
authors.initials: O
authors.lastname: Høie
authors.affiliation: Department of Surgery, The National University Hospital of Iceland, Reykjavik, Iceland.
authors.forename: Tryggvi
authors.initials: T
authors.lastname: Stefansson
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway13Department of Research and Development, Telemark Hospital, Skien, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Hoff
authors.affiliation: Department of Health Management and Health Economy, University of Oslo, Oslo, Norway2Department of Transplantation Medicine and KG Jebsen Center for Colorectal Cancer Research, Oslo University Hospital, Oslo, Norway 3Department of Epidemiology, Harvard T.
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
mesh_terms: D015746:Abdominal Pain / Q000453:epidemiology / Q000209:etiology; D000236:Adenoma / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D002245:Carbon Dioxide / Q000494:pharmacology; D003113:Colonoscopy / Q000009:adverse effects / Q000379:methods; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007327:Insufflation / Q000009:adverse effects / Q000379:methods; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000706:statistics & numerical data; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D009664:Norway / Q000453:epidemiology; D010043:Outcome and Process Assessment, Health Care; D010358:Patient Participation / Q000706:statistics & numerical data; D011044:Poland / Q000453:epidemiology; D018570:Risk Assessment / Q000379:methods / Q000706:statistics & numerical data; D013548:Sweden / Q000453:epidemiology
chemical_list: D002245:Carbon Dioxide