Limitations of liver biopsy and non-invasive diagnostic tests for the diagnosis of nonalcoholic fatty liver disease/nonalcoholic steatohepatitis

Table 3 Scoring systems for picking up nonalcoholic steatohepatitis or severe fibrosis in nonalcoholic fatty liver disease

Index	NAFIC score		NAFLDfibrosis score		FIB4 index
Object	Predicting NASH		Excluding severe fibrosis (stage 3-4)
Formula	Ferritin > 200 (female), 300 (male) ng/mL (= 1 point) Fasting insulin > 10 μU/mL (= 1 point) Type 4 collagen 7S > 5.0 ng/mL (= 2 points) Total: 0-4 points		-1.675 + 0.037 × age (yr) + 0.094 × BMI (kg/m2) + 1.13 × impaired fasting glycemia /DM (yes = 1, no = 0) + 0.99 × AAR – 0.013 × PLT (× 109/L) - 0.66 × Alb (g/dL)		Age (yr) × AST (IU/L)/(PLT (109/L) ×√ALT (IU/L)
Cut-off values	1	2	-1.455	0.676	1.30	2.67
Sensitivity	94%1	66%1	82%1	51%1	74%	33%
	88%2	60%2	77%2	43%2
Specificity	48%1	91%1	77%1	98%1	71%	98%
	43%2	87%2	71%2	96%2
Positive predictive value	31%1	90%1	56%1	90%1	43%	80%
	66%2	85%2	52%2	82%2
Negative predictive value	86%1	67%1	93%1	85%1	90%	83%
	75%2	64%2	88%2	80%2

¹Estimation group;

²Validation group. AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; AAR: AST/ALT ratio; BMI: Body mass index; DM: Diabetes mellitus; PLT: Platelets; NASH: Nonalcoholic steatohepatitis; NAFLD: Nonalcoholic fatty liver disease.