Knowledge of the presence of cirrhosis is important for the management of patients with chronic Hepatitis C.
Most models for predicting cirrhosis were derived from small numbers of patients and included subjective variables or laboratory tests that are not readily available.
Dr Anna Lok and colleagues developed a predictive model of cirrhosis in patients with chronic Hepatitis C based on standard laboratory tests.
The investigative team analyzed data from 1141 chronic Hepatitis C patients including 429 with cirrhosis.
All biopsies were read by a panel of pathologists, who were blinded to clinical features, and fibrosis stage was determined by consensus.
| A cutoff greater than 0.5 to confirm cirrhosis will misclassify 15% of patients without cirrhosis|
The team divided the cohort into a training set including 783 patients and a validation set, which included 358 patients.
Variables that were significantly different between patients with and without cirrhosis in univariate analysis were entered into logistic regression models.
The investigative team compared the performance of each model.
The final model comprised of platelet count, the alanine aminotranferease/aspartate aminotransferase ratio, and the international normalized ratio for blood coagulation.
The investigators found that the area under the receiver-operating characteristic curve of the final model in the training set was 0.78 vs 0.81 in the validation set.
The team noted that a cutoff of less than 0.2 to exclude cirrhosis would misclassify only 8% of patients with cirrhosis.
However, a cutoff of greater than 0.5 to confirm cirrhosis would misclassify 15% of patients without cirrhosis.
The investigators observed that the model performed equally well in fragmented and nonfragmented biopsies and in biopsies of varying lengths.
The team noted that use of this model might obviate the requirement for a liver biopsy in 50% of patients with chronic Hepatitis C.
Dr Lok's team concludes, ďA model based on standard laboratory test results can be used to predict histological cirrhosis with a high degree of accuracy in 50% of patients with chronic Hepatitis C.