This study was conducted to develop a simple surrogate index comprised of routinely available laboratory tests to reflect the histological fibrosis stage. Clinical characteristics and laboratory data from 368 and 249 consecutive patients with chronic hepatitis C, a training cohort and a validation cohort, respectively, were retrospectively evaluated. Platelet (Plt) count and albumin (Alb) level contributed to the discrimination of the respective fibrosis stages. We derived the fi brosis index (FI), FI = 8.0-0.01 x Plt (10 multiply 3/microliter) - Alb (g/dl), from a multiple regression model. FI significantly correlated with the histological fibrosis stage in both the initial and validation cohort at p=0.691 and p=0.661, respectively (Spearman's rank correlation coefficient, p<0.0001). The sensitivity and positive predictive value of FI at a cutoff value < 2.10 for predicting fibrosis stage F0-1 were 66.8% and 78.8% in the initial cohort and 68.5% and 63.6% in the validation cohort, respectively. Corresponding values of FI at a cutoff value >- 3.30 for the prediction of F4 were 67.7% and 75.0% in the initial cohort and 70.8% and 81.0% in the validation cohort. The fibrosis index comprised of platelet count and albumin level reflected the histological fibrosis stage in patients with chronic hepatitis C.</p
