Automatic and unbiased assessment of competence in colonoscopy: exploring validity of the Colonoscopy Progression Score (CoPS)

Background and aims: Colonoscopy is a difficult procedure to master. Increasing demands for colonoscopy, due to screening and surveillance programs, have highlighted the need for competent performers. Valid methods for assessing technical skills are pivotal for training and assessment. This study is the first clinical descriptive report of a novel colonoscopy assessment tool based on Magnetic Endoscopic Imaging (MEI) data and the aim was to gather validity evidence based on the data collected using the “Colonoscopy Progression Score” (CoPS). Methods: We recorded 137 colonoscopy procedures performed by 31 endoscopists at three university hospitals. The participants performed more than two procedures each (range 2 – 12) and had an experience of 0 – 10 000 colonoscopies. The CoPS was calculated for each recording and validity was explored using a widely accepted contemporary framework. The following sources of validity evidence were explored: response process (data collection), internal structure (reliability), relationship to other variables (i. e. operator experience), and consequences of testing (pass/fail). Results: Identical set-ups at all three locations ensured uniform data collection. The Generalizability coefficient (G-coefficient) was 0.80, and a Decision-study (D-study) revealed that four recordings were sufficient to ensure a G-coefficient above 0.80. We showed a positive correlation between CoPS and experience with Pearson’s r of 0.61 (P < 0.001). A pass/fail standard of 107 points was established using the contrasting group method to explore the consequences of testing. Conclusion: This study provides evidence supporting the validity of the CoPS for use in assessing technical colonoscopy performance in the clinical setting. Study registration: NCT01997177.