Noninvasive simple scores have been validated to assess advanced liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). We performed a systematic review with meta-analysis evaluating if NAFLD fibrosis score (NFS), AST to platelet ratio index (APRI), and Fibrosis-4 (FIB-4) score may also predict mortality. PubMed and EMBASE databases were searched until April 2018. Random-effects models were used to calculate pooled RRs of mortality for highest vs. lowest categories of exposure and to perform dose-response meta-analysis. Heterogeneity was assessed using the Q test and I² statistic. Overall, eight studies were included in the systematic review; all of the eight studies provided data for NFS, while four provided data for APRI and FIB-4. When comparing the risk estimates for high (>0.676) vs. intermediate + low NFS (≤0.676), we found a nearly fourfold increase in mortality risk, with evidence of heterogeneity (RR = 3.85, 95% CI: 2.08, 7.11; I² = 92%). At dose-response meta-analysis, compared to the midpoint of the lowest category of NFS (-2.5), the risk of mortality was about twofold higher for NFS = -0.5 (RR = 2.20, 95% CI: 1.31, 3.70) and more than fivefold higher for NFS = 1.5 (RR = 5.16, 95% CI: 2.02, 13.16). When comparing the risk estimates for high (>1.5) vs. medium + low APRI (≤1.5), we found a higher risk of mortality, without heterogeneity (RR = 3.61, 95% CI: 1.79, 7.28; I² = 0%). Comparison of the risk estimates for high (>2.67) vs. medium + low FIB-4 (≤2.67) didn't reveal a significantly higher risk of mortality, with heterogeneity (RR = 2.27, 95% CI: 0.72, 7.15; I² = 85%). Dose-response analysis for APRI and FIB-4 was not considered conclusive due to the low number of studies. Based on the results of our meta-analysis, the measurement of NFS can be considered an accurate tool for the stratification of the risk of death in patients with NAFLD.
Keywords: APRI; FIB-4; NAFLD fibrosis score; mortality.