Abstract
BACKGROUND: To enhance early liver disease detection, a clinical pathway integrating reflex AST testing and automated AAR reporting was implemented. We aim to evaluate the long-term effectiveness of introducing reflex AST testing by assessing its impact after implementation in 2 regions of Wales. METHODS: We applied a quasi-experimental, Difference-in-Difference approach to evaluate the introduction of the reflex AST:ALT pathway in Wales (January 2010 to December 2023). Outcomes were the monthly incidence rate of (1) chronic liver disease (including cirrhosis) and (2) cirrhosis in the 2 intervention regions versus the control regions. RESULTS: In total, 78,917 individuals with liver disease were included in the study. A significant increase in cirrhosis diagnoses was observed in both regions (first region: incidence rate ratio=1.24, 95% CI: 1.15-1.34, p<0.001; second region: incidence rate ratio=1.16, 95% CI: 1.02-1.33, p=0.028). The incidence of composite chronic liver disease (including cirrhosis) increased transiently in the second region only (incidence rate ratio=1.35, 95% CI: 1.16-1.56, p<0.001). CONCLUSIONS: In this long-term, population-level evaluation, reflex AST:ALT testing increased cirrhosis detection in both regions and produced a short-term rise in chronic liver disease (including cirrhosis) diagnoses one region, strengthening the evidence of the pathway's effect on cirrhosis detection. Further study is warranted to understand regional variation.