Validation of Dynamic Aspartate‐to–Alanine Aminotransferase Ratio for Predicting Liver Disease Mortality

The dynamic aspartate‐to–alanine aminotransferase ratio (dAAR) was developed recently to predict the risk of incident chronic liver disease among the Nordic adult population; however, the dAAR has not been externally validated in other ethnic cohorts. Therefore, we aimed to examine the predictive ability of dAAR for liver disease mortality in the South Korean adult population. As a population‐based cohort study, we used the National Health Screening Cohort database, which included adult individuals who underwent standardized medical examinations between 2002 and 2003 in South Korea. The primary endpoint was liver disease mortality, defined as death due to liver disease. Liver disease mortality was evaluated between 2004 and 2015 (12 years). Analysis of data from 512,749 adults showed that 4,052 (0.8%) individuals died due to liver disease. On receiver operating characteristic (ROC) analyses, the area under curve for alanine aminotransferase (ALT), aspartate‐to‐ALT ratio (AAR), and dAAR for liver disease mortality were 0.74, 0.55, and 0.81, respectively. The cutoff point of dAAR was determined to be 0.72 on ROC analysis, using the Youden index method. On competing risk analysis using the Fine and Gray model, the dAAR > 0.72 group demonstrated a 4.43‐fold higher rate of liver disease mortality (subdistribution hazard ratio: 4.43, 95% confidence interval: 4.11, 4.77; P < 0.001) after adjustment for covariates. Conclusion: The performance of dAAR in predicting liver disease mortality was better than that of AAR or ALT in South Korea. Our study suggests that dAAR scores can potentially be used for screening and predicting liver disease mortality among the general Korean population.