Source: Lindor, K.D. et al. 1994. Ursodeoxycholic acid in the treatment of primary biliary cirrhosis.  Gastroenterology 106: 1284-1290.
Event type: 1 = death; 2 = liver transplant; 3 = histologic progression; 4 = appearance of esophogeal varices
Event type: 5 = ascites; 6 = encephalopathy; 7 = doubling of bilirubin; 8 = worsening of symptom score by 2