Diagnostic performance of FibroTest-ActiTest, transient elastography, and the fibrosis-4 index in patients with autoimmune hepatitis using histological reference

Table 4 Comparison of the diagnostic performance of biopsy, ActiTest, and alanine aminotransferase for advanced activity (A2 and A3) with the gold standard model and Bayesian latent class model

Parameters and cutoffs	Biopsy assumed as perfect reference	Bayesian LCM	Gold standard model vs LCM
Number of patients	103	103	Difference (Z-test P-value)
Prevalence advanced activity	61.2 (51.0-70.5)	47.8 (37.7-58.3)	13.4% decrease (0.07)
Biopsy stage METAVIR ≥ A2
Sensitivity	100	95.8 (87.5-99.6)	4.2% decrease (NA)
Specificity	100	70.9 (57.4-82.3)	29.1% decrease (NA)
Positive predictive value	100	75.1 (62.7-85.6)	24.9% decrease (NA)
Negative predictive value	100	94.8 (84.5-99.5)	5.2% decrease (NA)
ActiTest with cutoff of > 0.52
Sensitivity	73.0 (60.1-83.1)	97.3 (85.8-100)	24.3% increase (0.006)
Specificity	95.0 (81.8-99.1)	99.4 (93.4-100)	4.4% increase (0.59)
Positive predictive value	95.8 (84.6-99.3)	99.3 (92.6-100)	3.5% increase (0.60)
Negative predictive value	69.1 (55.0-80.5)	97.7 (86.6-100)	28.6% increase (0.002)
ALT with cutoff of ≥ 50
Sensitivity	81.0 (68.7-89.4)	99.5 (95.0-100)	18.5% increase (0.006)
Specificity	70.0 (53.3-82.9)	74.3 (61.6-85.7)	4.2% increase (0.69)
Positive predictive value	81.0 (68.7-89.4)	78.0 (65.8-88.4)	3.0% decrease (0.73)
Negative predictive value	70.0 (53.3-82.9)	99.4 (94.0-100)	29.4% increase (0.006)

LCM: Latent class model; METAVIR: Meta-analysis of Histological Data in Viral Hepatitis; ALT: Alanine aminotransferase; NA: Not applicable.