title: Gradual stiffness versus magnetic imaging-guided variable stiffness colonoscopes: A randomized noninferiority trial.
abstract: BACKGROUND
  Colonoscopes with gradual stiffness have recently been developed to enhance cecal intubation.
  
  
  OBJECTIVE
  We aimed to determine if the performance of gradual stiffness colonoscopes is noninferior to that of magnetic endoscopic imaging (MEI)-guided variable stiffness colonoscopes.
  
  
  METHODS
  Consecutive patients were randomized to screening colonoscopy with Fujifilm gradual stiffness or Olympus MEI-guided variable stiffness colonoscopes. The primary endpoint was cecal intubation rate (noninferiority limit 5%). Secondary endpoints included cecal intubation time. We estimated absolute risk differences with 95% confidence intervals (CIs).
  
  
  RESULTS
  We enrolled 475 patients: 222 randomized to the gradual stiffness instrument, and 253 to the MEI-guided variable stiffness instrument. Cecal intubation rate was 91.7% in the gradual stiffness group versus 95.6% in the variable stiffness group. The adjusted absolute risk for cecal intubation failure was 4.3% higher in the gradual stiffness group than in the variable stiffness group (upper CI border 8.1%). Median cecal intubation time was 13 minutes in the gradual stiffness group and 10 minutes in the variable stiffness group (p< 0.001).
  
  
  CONCLUSIONS
  The study is inconclusive with regard to noninferiority because the 95% CI for the difference in cecal intubation rate between the groups crosses the noninferiority margin. (ClinicalTrials.gov identifier: NCT01895504).
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway; Department of Transplantation Medicine, Section of Gastroenterology, Oslo University Hospital, Norway; Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway.
authors.forename: Kjetil
authors.initials: K
authors.lastname: Garborg
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway.
authors.forename: Håvard
authors.initials: H
authors.lastname: Wiig
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway.
authors.forename: Audun
authors.initials: A
authors.lastname: Hasund
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway.
authors.forename: Jon
authors.initials: J
authors.lastname: Matre
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway; Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway.
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Holme
authors.affiliation: Department of Medicine, Sorlandet Hospital, Arendal, Norway.
authors.forename: Geir
authors.initials: G
authors.lastname: Noraberg
authors.affiliation: Department of Transplantation Medicine, Section of Gastroenterology, Oslo University Hospital, Norway; Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway.
authors.forename: Magnus
authors.initials: M
authors.lastname: Løberg
authors.affiliation: Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway; Telemark Hospital, Skien, Norway.
authors.forename: Mette
authors.initials: M
authors.lastname: Kalager
authors.affiliation: Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway; Harvard T. H. Chan School of Public Health, Boston, MA, USA; Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Hans-Olov
authors.initials: HO
authors.lastname: Adami
authors.affiliation: Department of Medicine, Sorlandet Hospital, Kristiansand, Norway; Department of Transplantation Medicine, Section of Gastroenterology, Oslo University Hospital, Norway; Department of Health Economy and Health Management and KG Jebsen Center of Colorectal Cancer Research, University of Oslo, Norway.
authors.forename: Michael
authors.initials: M
authors.lastname: Bretthauer
keywords: Endoscopy; colonoscopy; innovation