Distinct age-dependent phenotypes of abnormal liver function tests derived from national Emergency Department data.

BackgroundAbnormal liver function tests (LFTs) are frequently performed in Emergency Departments (EDs); however, the systematic characterization of age-dependent clinical phenotypes and pathogen associations remains limited.PurposeHere we aimed to identify the distinct clinical presentations and pathogen-specific associations of pediatric and adult ED visits for abnormal LFTs.MethodsThis retrospective cohort study analyzed 26,874 ED visits for abnormal LFTs in South Korea's National Emergency Department Information System (2019-2023). Patients were stratified into pediatric (0-18 years) and adult (19-64 years) groups. We characterized the clinical presentations, concurrent diagnoses, temporal correlations with infectious pathogens, and metabolic comorbidity patterns.ResultsThe ED visits included 3,152 pediatric (11.7%) and 23,722 adult patients (88.3%). Pediatric presentations demonstrated fever-predominant profiles (47.3%), respiratory symptoms (6.4%), and infectious disease diagnoses (39.8%) as well as temporal correlations with respiratory viruses (rhinovirus, r=0.30; adenovirus, r=0.28; P