Objective: To create a simple diagnostic index I for noninvasive distinguish between mild and significant liver fibrosis (stages 0-2 versus 3-6 according to Ishak's criteria) among patients with chronic hepatitis C (CHC).
Patients and methods: Consecutive interferon-naive 572 CHC patients (F/M: 246/326; median age: 43 years). The I index was created on the data from training group (341 patients diagnosed in 1995-2000 years) and its discriminative value was then assessed separately in training group, validation group (231 patients diagnosed in 2001-2003 years) and entire group using among other things the AUROC measure.
Results: The I index is based on information about patient's age, alcohol abuse, AST activity and platelet counts. The AUROC measures were 0.875 [95% CI (0.833-0.916)], 0.926 [95% CI (0.889-0.962)] and 0.890 [95% CI(0.860-0.921)] for training, validation and entire group, respectively. The I values corresponding to at least 95% of sensitivity (observed in about 40% of all patients) could excluded the stage 0-2 with accuracy close to 100%. Based on I values corresponding to at least 95% of specificity (observed in about 17% of all patients) the presence of stage 3-6 could be confirmed with accuracy of about 70%. The I index possesses the statistically significant ability to distinguish between mild and significant fibrosis and seems to be useful in monitoring of non-treated patient with mild fibrosis.