Impact of Income-to-Poverty Ratio on Long-Term Mortality of Persons with Chronic Liver Disease in the USA, 1999–2018

INTRODUCTION: Chronic liver disease (CLD) is associated with increased morbidity and mortality. Understanding health disparities can inform appropriate interventions. We aimed to study mortality outcomes of those with CLD by the income level (income-to-poverty ratio <5 as lower income and ≥5 as higher income). METHODS: In this retrospective cohort study, we analyzed data of adults from the National Health and Nutrition Examination Survey, 1999-2018. CLD included viral hepatitis, nonalcoholic fatty liver disease (NAFLD), and alcohol-associated liver disease (ALD). RESULTS: We analyzed 59,204 adults: 47,224 without CLD and 11,980 with CLD. The CLD group was older, more likely male, racial/ethnic minority groups or foreign-born, and had lower educational and income levels (p < 0.001). Most (80.02%) CLD participants did not have college degrees and had lower income (79.18%). Among CLD participants, similar differences were observed between lower and higher income groups. Lower income participants with CLD had significantly higher 10-year cumulative mortality compared to higher income CLD participants (15.26 vs. 8.00%, p < 0.001), with consistent findings in viral hepatitis and NAFLD subgroups (p < 0.001) but not ALD (p = 0.71). Adjusting for age, sex, race, birthplace, lower income CLD participants were 2.01 (hazard ratio [HR]: 2.01; 95% CI: 1.79-2.26) times more likely to die overall and in viral hepatitis (HR: 2.05; 95% CI: 1.31-3.24) and NAFLD subgroups (HR: 2.32; 95% CI: 1.69-3.18) but not ALD (HR: 1.17; 95% CI: 0.55-2.51). CONCLUSION: Lower income, foreign-born, and racial/ethnic minority groups were disproportionately represented among those with CLD, with lower income and CLD individuals having double the mortality risk compared to their higher income counterparts. Interventions should be culturally appropriate and address socioeconomic barriers.