Adaptation of the Mayo primary biliary cirrhosis natural history model forapplication in liver transplant candidates

The Mayo natural history model has been used widely as a tool to estimate p rognosis in patients with primary biliary cirrhosis (PBC), particularly liv er transplant candidates, We present an abbreviated model in which a tabula r method is used to approximate the risk score, which may be incorporated i n the minimal listing criteria for liver transplant candidates. Data used i n the development and validation of the original Mayo model were derived fr om 418 patients with well-characterized PBC, To construct an abbreviated ri sk score in a format similar to that of Child-Turcotte-Pugh score, 1 to 3 c ut-off criteria mete determined for each variable, namely age (0 point for <38, 1 for 38 to 62 and 2 for greater than or equal to 63 years), bilirubin (0 point for <1, 1 for 1 to 1.7, 2 for 1.7 to 6.4, and 3 for >6.4 mg/dL), albumin (0 point for >4.1, 1 for 2.8 to 4.1, and 2 for <2.8 g/dL), prothrom bin time (1 point for normal and 2 for prolonged) and edema (0 point for ab sent and 1 for present). The intervals between these criteria were chosen i n a may to enable a meaningful classification of patients according to thei r risk for death. This score is highly correlated with the original risk sc ore (r = 0.93; P <.01). The Kaplan-Meier estimate at 1 year was 90.6% in pa tients with a score of 6. The abbreviated risk score is a convenient method to quickly estimate the risk score in patients with PBC, An abbreviated sc ore of 6 may be consistent with the current minimal listing criteria in liv er transplant candidates.