Objective: To describe a natural history model for primary sclerosing cholangitis (PSC) that is based on routine clinical findings and test results and eliminates the need for liver biopsy.
Patients and methods: Using the Cox proportional hazards analysis, we created a survival model based on 405 patients with PSC from 5 clinical centers. Independent validation of the model was undertaken by applying it to 124 patients who were not included in the model creation.
Results: Based on the multivariate analysis of 405 patients, a risk score was defined by the following formula: R = 0.03 (age [y]) + 0.54 loge (bilirubin [mg/dL]) + 0.54 loge (aspartate aminotransferase [U/L]) + 1.24 (variceal bleeding [0/1]) - 0.84 (albumin [g/dL]). The risk score was used to obtain survival estimates up to 4 years of follow-up. Application of this model to an independent group of 124 patients showed good correlation between estimated and actual survival.
Conclusions: A new model to estimate patient survival in PSC includes more reproducible variables (age, bilirubin, albumin, aspartate aminotransferase, and history of variceal bleeding), has accuracy comparable to previous models, and obviates the need for a liver biopsy.