title: Is forceps more useful than visualization for measurement of colon polyp size?
abstract: OBJECTIVE
  To identify whether the forceps estimation is more useful than visual estimation in the measurement of colon polyp size.
  
  
  METHODS
  We recorded colonoscopy video clips that included scenes visualizing the polyp and scenes using open biopsy forceps in association with the polyp, which were used for an exam. A total of 40 endoscopists from the Busan Ulsan Gyeongnam Intestinal Study Group Society (BIGS) participated in this study. Participants watched 40 pairs of video clips of the scenes for visual estimation and forceps estimation, and wrote down the estimated polyp size on the exam paper. When analyzing the results of the exam, we assessed inter-observer differences, diagnostic accuracy, and error range in the measurement of the polyp size.
  
  
  RESULTS
  The overall intra-class correlation coefficients (ICC) of inter-observer agreement for forceps estimation and visual estimation were 0.804 (95%CI: 0.731-0.873, P < 0.001) and 0.743 (95%CI: 0.656-0.828, P < 0.001), respectively. The ICCs of each group for forceps estimation were higher than those for visual estimation (Beginner group, 0.761 vs 0.693; Expert group, 0.887 vs 0.840, respectively). The overall diagnostic accuracy for visual estimation was 0.639 and for forceps estimation was 0.754 (P < 0.001). In the beginner group and the expert group, the diagnostic accuracy for the forceps estimation was significantly higher than that of the visual estimation (Beginner group, 0.734 vs 0.613, P < 0.001; Expert group, 0.784 vs 0.680, P < 0.001, respectively). The overall error range for visual estimation and forceps estimation were 1.48 ± 1.18 and 1.20 ± 1.10, respectively (P < 0.001). The error ranges of each group for forceps estimation were significantly smaller than those for visual estimation (Beginner group, 1.38 ± 1.08 vs 1.68 ± 1.30, P < 0.001; Expert group, 1.12 ± 1.11 vs 1.42 ± 1.11, P < 0.001, respectively).
  
  
  CONCLUSIONS
  Application of the open biopsy forceps method when measuring colon polyp size could help reduce inter-observer differences and error rates.
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Seun Ja
authors.initials: SJ
authors.lastname: Park
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Jong Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Tae Oh
authors.initials: TO
authors.lastname: Kim
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Hyung Wook
authors.initials: HW
authors.lastname: Kim
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Sang Heon
authors.initials: SH
authors.lastname: Lee
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Baek
authors.affiliation: Jae Hyun Kim, Seun Ja Park, Department of Gastroenterology, Kosin University College of Medicine, Busan 602-702, South Korea.
authors.forename: Busan Ulsan Gyeongnam Intestinal Study Group Society
authors.initials: BU
authors.lastname: Bigs
mesh_terms: D018256:Adenomatous Polyps / Q000473:pathology*; D001706:Biopsy; D002983:Clinical Competence; D003111:Colonic Polyps / Q000473:pathology*; D003113:Colonoscopy / Q000295:instrumentation*; D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D007600:Judgment; D015588:Observer Variation; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013525:Surgical Instruments; D014741:Video Recording; D014796:Visual Perception
keywords: Colon polyp; Colonoscopy; Endoscopy; Measurement