Is testing of aspartate aminotransferase necessary along with every alanine aminotransferase for health check in elderly individuals?

Objective: This study is to evaluate whether Aspartate Aminotransferase (AST) is necessary to screen for liver function in apparently healthy elderly individuals. Methods: We derived the proportions of elevated ASTs that would not be measured based on 2018-year of paired Chinese elderly (Age >= 65 years old) check-up. Defined as AST > 40U/L is elevated. The relationship between alanine aminotransferase (ALT) and AST was analyzed by using Pearson's approach. Receiver operating characteristics curve analysis was used to evaluate the predictive accuracy of ALT for abnormal AST. Results: 52,857 pairs of ALT and AST were analyzed. Serum AST was found to be positively correlated with serum ALT, r = 0.81, p < 0.01 for the entire cohort. The receiver operating characteristics (ROC) curve of ALT for predicting positive AST is 0.918. The optimal threshold for ALT is 28 U/L with the sensitivity of 82.6%, and specificity of 86.8%. At the threshold, below 0.7% of subjects with positive AST were missed, but approximately 83% of the AST tests were eliminated. Conclusion: Our study showed that tests of AST were not necessary along with every ALT test for health check in elderly individuals. An estimated 84.5% of subjects were not needed for AST tests which could have saved about CN(sic) 815 million (USD$115 million or EURO$100 million) every year.