Amebic Liver Abscess Hospitalizations in the United States: A Nationwide Analysis of Trends and Severe Morbidity, 2002-2023.

AIMS: US population-based data on amebic liver abscess (ALA) are limited and predate the ICD-10-CM era. We quantified national trends, inpatient outcomes, and factors associated with severe in-hospital morbidity among adult ALA hospitalizations. METHODS AND RESULTS: We performed a retrospective cross-sectional analysis of the 2002-2023 National Inpatient Sample, excluding 2015. ALA was identified by ICD-9-CM 006.3 or ICD-10-CM A06.4 in any diagnosis position. The primary morbidity outcome was a composite of severe sepsis, acute kidney injury, liver-related decompensation, gram-negative septicemia, or unspecified septicemia. Survey-weighted analyses incorporated discharge weights, strata, and clustering. We identified 688 ALA hospitalizations, representing 3,314 weighted national hospitalizations (95% CI, 2,982-3,646). The annual proportion declined (P<0.001). ALA hospitalizations were predominantly male (77.6%), frequently Hispanic (51.7%), and concentrated in the West (45.6%). A coded drainage/aspiration procedure was present in 57.2%. The severe morbidity composite occurred in 25.1% of ALA versus 15.1% of general adult hospitalizations (P<0.001). Mean length of stay (8.64 vs 4.83 days) and mean 2023 charges ($82,964 vs $55,508) were higher (both P<0.001). Coagulopathy was the only factor retained after backward elimination (adjusted OR, 3.82; 95% CI, 1.49-9.77; P=0.006), but final-model discrimination was poor (c-statistic, 0.560). CONCLUSION: ALA remains a rare but high-morbidity coded inpatient diagnosis in the United States. Administrative variables did not yield a clinically useful individual-level risk prediction model.