Latent Class Analysis of Noninvasive Methods and Liver Biopsy in Chronic Hepatitis C: An Approach without a Gold Standard

AIMS: To evaluate the applicability of the Latent Class Analysis (LCA) and accuracy of transient elastography (TE), aspartate-to-platelet-ratio-index (APRI), enhanced liver fibrosis (ELF), and liver biopsy (LB) for liver fibrosis assessment in a model without a gold standard. METHODS: Significant fibrosis was defined as TE ≥ 7.1 kPa, APRI ≥ 1.5, ELF ≥ 9.37, or LB METAVIR F ≥ 2. Cirrhosis was defined as TE ≥ 12.5 kPa, APRI ≥ 2.0, ELF ≥ 10.31, or LB as METAVIR F = 4. RESULTS: 117 patients with chronic hepatitis C were included. In the LCA, for significant fibrosis the sensitivities and specificities (95% CI) were 0.92 (0.86–0.98) and 0.79 (0.72–0.86) for TE; 0.47 (0.40–0.54) and 0.99 (0.95–1.00) for APRI; 0.81 (0.74–0.88) and 0.78 (0.71–0.85) for ELF; and 0.86 (0.68–1.00) and 0.91 (0.79–1.00) for LB. For cirrhosis, the sensitivities and specificities were 0.92 (0.76–1.00) and 0.94 (0.91–0.97) for TE; 0.57 (0.37–0.77) and 0.97 (0.93–1.00) for APRI; 0.94 (0.84–1.00) and 0.88 (0.82–0.94) for ELF; and 0.30 (0.12–0.48) and 1.00 for LB. CONCLUSION: LCA was useful to evaluate accuracy of methods for liver fibrosis staging. Sensitivities and specificities of noninvasive methods were increased in LCA compared to the use of LB as the gold standard.