Table 3.
Cut-off values to predict the presence of NASH and fibrosis.
| Cut-Off Value | Sens | Spec | PPV | NPV | |
|---|---|---|---|---|---|
| NASH | 0.2575 | 72.60% | 71.60% | 75.30% | 68.70% |
| Def NASH | 0.2575 | 87.60% | 61.80% | 38.10% | 92.50% |
| Sign F | 13.25 | 73.60% | 51.40% | 36.50% | 83.70% |
| Adv F | 10.1 | 63.50% | 69.90% | 30.00% | 90.50% |
| Cirrhosis | 5.05 | 51.50% | 95.30% | 52.80% | 96.00% |
| NASH | >1.1210 | 82.90% | |||
| No NASH | <−0.6185 | 80.00% | |||
| Def NASH | >1.1346 | 64.10% | |||
| No def NASH | <0.0120 | 93.30% | |||
| Sign F | <7.05 | 53.70% | |||
| No sign F | >17.45 | 86.50% | |||
| Adv F | <7.05 | 46.30% | |||
| No adv F | >18.25 | 90.70% | |||
| Cirrhosis | <6.55 | 30.50% | |||
| No cirrhosis | >19.45 | 94.70% |
Cut-off values to predict the presence of NASH in patients without significant fibrosis; and to predict fibrosis in the whole population with sensitivity, specificity, positive predictive value and negative predictive value. One and two cut-off models were created for each parameter. Using 1 cut-off, the PPV for definite NASH was low (78/162, 38.1%), but of those misclassified as definite NASH, 52% had borderline NASH. Using 2 cut-offs, the PPV for definite NASH was better (41/64, 64.1%), and with 61% of those misclassified having borderline NASH. Using two cut-off values can lead to patients with an indeterminate value. This “indeterminate” classification was present in 54%, 36%, 65%, 68% and 74% of cases for NASH, definite NASH, significant fibrosis, advanced fibrosis and cirrhosis, respectively. Def, definite NASH; Sign F, significant fibrosis; Adv F, advanced fibrosis; Sens, sensitivity; Spec, specificity; PPV, positive predictive value; NPV, negative predictive value.