ADAPTATION OF THE MAYO PRIMARY BILLARY CIRRHOSIS MODEL FOR MINIMUM LISTING CRITERIA FOR LIVER TRANSPLANT CADIDATES.

Abstract

199 The Mayo natural history model for primary biliary cirrhosis (PBC) has been developed and validated to estimate survival of patients with PBC in the absence of effective treatment. The AIM of this work is to simplify the mathematical computation of the Mayo PBC model so that it may be used as convenient minimum listing criteria. METHODS: The data set with which the Mayo model was developed included 418 patients with PBC. The original Cox model consisted of patient's age, serum levels of bilirubin and albumin, prothrombin time and peripheral edema. Based on regression coefficients of the model and the magnitude of influence of each variable on the risk score, a table was created in which a score up to 3 was assigned for each variable. The cut-off criteria for assigning these scores were selected in such a manner that the sum of the scores will approximate the original risk score.RESULTS: The table shows the adapted model. There was an excellent correlation between the new and original scores(r=0.9, p<0.01). The figure illustrates patient survival without OLT using the new scoring system.CONCLUSIONS: The Mayo model for PBC has been adapted so that an approximate risk score may be obtained without the use of a calculator. A total score of 7 or more may be used as minimum listing criteria for patients with PBC.