Development and validation of the SIMPLE endoscopic classification of diminutive and small colorectal polyps

SIMPLE classification investigator team, Marietta Iacucci, Cristina Trovato, Marco Daperno, Oluseyi Akinola, David Greenwald, Seth A Gross, Arthur Hoffman, Jeffrey Lee, Brendan C Lethebe, Mark Lowerison, Jennifer Nayor, Helmut Neumann, Timo Rath, Silvia Sanduleanu, Prateek Sharma, Ralf Kiesslich, Subrata Ghosh, John R Saltzman

Research output: Contribution to journalArticlepeer-review

11 Citations (Scopus)
349 Downloads (Pure)


BACKGROUND: Prediction of histology of small polyps facilitates colonoscopic treatment. The aims of this study were: 1) to develop a simplified polyp classification, 2) to evaluate its performance in predicting polyp histology, and 3) to evaluate the reproducibility of the classification by trainees using multiplatform endoscopic systems.

METHODS: In phase 1, a new simplified endoscopic classification for polyps - Simplified Identification Method for Polyp Labeling during Endoscopy (SIMPLE) - was created, using the new I-SCAN OE system (Pentax, Tokyo, Japan), by eight international experts. In phase 2, the accuracy, level of confidence, and interobserver agreement to predict polyp histology before and after training, and univariable/multivariable analysis of the endoscopic features, were performed. In phase 3, the reproducibility of SIMPLE by trainees using different endoscopy platforms was evaluated.

RESULTS: Using the SIMPLE classification, the accuracy of experts in predicting polyps was 83 % (95 % confidence interval [CI] 77 % - 88 %) before and 94 % (95 %CI 89 % - 97 %) after training (P  = 0.002). The sensitivity, specificity, positive predictive value, and negative predictive value after training were 97 %, 88 %, 95 %, and 91 %. The interobserver agreement of polyp diagnosis improved from 0.46 (95 %CI 0.30 - 0.64) before to 0.66 (95 %CI 0.48 - 0.82) after training. The trainees demonstrated that the SIMPLE classification is applicable across endoscopy platforms, with similar post-training accuracies for narrow-band imaging NBI classification (0.69; 95 %CI 0.64 - 0.73) and SIMPLE (0.71; 95 %CI 0.67 - 0.75).

CONCLUSIONS: Using the I-SCAN OE system, the new SIMPLE classification demonstrated a high degree of accuracy for adenoma diagnosis, meeting the ASGE PIVI recommendations. We demonstrated that SIMPLE may be used with either I-SCAN OE or NBI.

Original languageEnglish
Pages (from-to)779-789
Number of pages11
Issue number8
Early online date23 Mar 2018
Publication statusPublished - Aug 2018

Bibliographical note

Title of output changed between acceptance and publication. Original working title: 'Development and validation of the SIMPLE endoscopic classification of diminutive and colorectal small polyps'


  • virtual chromoendoscopy
  • colonic polyps
  • optical diagnosis


Dive into the research topics of 'Development and validation of the SIMPLE endoscopic classification of diminutive and small colorectal polyps'. Together they form a unique fingerprint.

Cite this