Web-based system for training and dissemination of a magnification chromoendoscopy classification

Abstract

Aim: To evaluate the use of web-based technologies to assess the learning curve and reassess reproducibility of a simplified version of a classification for gastric magnification chromoendoscopy (MC).

Methods: As part of a multicenter trial, a hybrid approach was taken using a CD-ROM, with 20 films of MC lasting 5 s each and an "autorun" file triggering a local HTML frameset referenced to a remote questionnaire through an Internet connection. Three endoscopists were asked to prospectively and independently classify 10 of these films randomly selected with at least 3 d apart. The answers were centrally stored and returned to participants together with adequate feedback with the right answer.

Results: For classification in 3 groups, both intra- [Cohen's kappa (kappa) = 0.79-1.00 to 0.89-1.00] and inter-observer agreement increased from 1st (moderate) to 6th observation (kappa = 0.94). Also, agreement with reference increased in the last observations (0.90, 1.00 and 1.00, for observers A, B and C, respectively). Validity of 100% was obtained by all observers at their 4th observation. When a 4th (sub)group was considered, inter-observer agreement was almost perfect (kappa = 0.92) at 6th observation. The relation with reference clearly improved into kappa (0.93-1.00) and sensitivity (75%-100%) at their 6th observations.

Conclusion: This MC classification seems to be easily explainable and learnable as shown by excellent intra- and inter-observer agreement, and improved agreement with reference. A web system such as the one used in this study may be useful for endoscopic or other image based diagnostic procedures with respect to definition, education and dissemination.

Figure 1

Graphical user interface for movie classification. The right frame is used to play a video clip loaded from the distributed CD; the left frame shows the patterns at the top and a form to retrieve user classifications.

Figure 2

Variation of agreement with reference (Kappa) and inter-observer agreement (Black) (top graphic) and validity (bottom graphic) along sequential observations (1st to 6th) for the classification in subgroups [dashed line marks for 0.80 as the cutoff for almost perfect agreement (top graphic) and validity (bottom graphic)].