Table 5.

Performance of IGF-1, alone or in a combination panel, and classical fibrosis scores in distinguishing F0-2 vs. F3-4 grades of fibrosis.

	Cutoff	AUROC (95% CI)	Sensitivity (95% CI)	Specificity (95% CI)	Accuracy (95% CI)	PPV (95% CI)	NPV (95% CI)	TP	TN	FP	FN
IGF-1	<98.83 ng/ml	0.67* (0.56–0.78)	0.70 (0.35–0.93)	0.61 (0.51–0.72)	0.63 (0.53–0.72)	0.17 (0.11–0.25)	0.95 (0.88–0.98)	7	60	37	3
APRI	>0.31	0.62 (0.43–0.81)	0.60 (0.26–0.88)	0.71 (0.61–0.80)	0.70 (0.60–0.79)	0.18 (0.11–0.28)	0.95 (0.89–0.97)	6	69	28	4
Fib-4	>0.75	0.66 (0.49–0.82)	0.90 (0.56–0.99)	0.47 (0.37–0.58)	0.51 (0.42–0.61)	0.15 (0.12–0.19)	0.98 (0.88–0.99)	9	46	51	1
NFS	>-0.96	0.74 (0.52–0.89)	0.43 (0.10–0.82)	0.88 (0.77–0.94)	0.83 (0.72–0.91)	0.28 (0.12–0.53)	0.93 (0.88–0.96)	3	56	8	4
Ferritin	>118 ng/ml	0.68* (0.49–0.87)	0.8 (0.44–0.97)	0.65 (0.55–0.74)	0.66 (0.57–0.75)	0.19 (0.13–0.26)	0.97 (0.90–0.99)	8	63	34	2
INR	>1.03	0.78* (0.64–0.93)	0.70 (0.35–0.93)	0.85 (0.76–0.91)	0.83 (0.75–0.90)	0.32 (0.20–0.46)	0.96 (0.91–0.99)	7	82	15	3
IGF-1 + ferritin + INR	-	0.81* (n.d.)	0.50 (0.19–0.81)	0.98 (0.93–0.99)	0.93 (0.87–0.97)	0.71 (0.37–0.91)	0.95 (0.91–0.97)	5	95	2	5

Applied in the validation cohort. NSF, n = 71; others, n = 107. F3-4 is considered as positive if the levels of each parameter are superior or inferior to the cutoff value as indicated. p-values corrected with Benjamini–Hochberg procedure, assuming 5% false discovery rate.

APRI, aspartate aminotransferase-to-platelet ratio; CI, confidence interval; FN, false negative; FP, false positive; IGF-1, insulin-like growth factor 1; INR, international normalized ratio; NFS, NAFLD fibrosis score; NPV, negative predictive value; PPV, positive predictive value; TN, true negative; TP, true positive; n.d., not determined due to the low number of F3-4 patients.

^*p < 0.05.