Lewis Score

Because of concerns that adding the scores from each tertile in a case of mild disease could provide a total number greater than one tertile of severe disease, it was chosen to calculate the score based on the most severe tertile plus the stenosis score. Thus, a total score was created as follows:

Maximum tertile score {[(Villous parameter × extent × descriptor) + (Ulcer parameter × extent × size)] for tertile 1 or [(Villous parameter × extent × descriptor) + (Ulcer parameter × extent × size)] for tertile 2 or [(Villous parameter × extent × descriptor) + (Ulcer parameter × extent × size)] for tertile 3} + (Stenosis number × ulcerated × traversed).