Inpatient outcomes by socioeconomic characteristics among younger adults hospitalized with gastrointestinal malignancies in the United States, 2018–2022.

e23168 Background: Early-onset gastrointestinal (GI) cancers are increasingly recognized, yet national data describing inpatient outcomes and socioeconomic differences among younger adults remain limited. Methods: A serial cross-sectional, survey-weighted analysis was conducted using the 2018–2022 Healthcare Cost and Utilization Project National Inpatient Sample. Adult hospitalizations among younger adults (age < 50 years) with a principal diagnosis of GI malignancy were identified. Socioeconomic exposures included primary payer and neighborhood income quartile. Outcomes included in-hospital mortality (primary), length of stay (LOS), hospitalization cost estimated using cost-to-charge ratios, and discharge to facility. National estimates accounted for survey weighting, clustering, and stratification. Multivariable survey-weighted logistic and linear regression models adjusted for age, sex, race, cancer subtype, calendar year, elective admission status, APR-DRG severity, hospital teaching status, geographic region, payer, and income quartile. Results: The cohort included 21,775 unweighted admissions, representing an estimated 108,875 hospitalizations nationally. Overall in-hospital mortality was 2.19%. After adjustment, Medicare coverage was associated with higher in-hospital mortality compared with private insurance (odds ratio [OR] 5.38, 95% CI 1.67–17.34), while elective admission was associated with lower mortality (OR 0.59, 95% CI 0.35–0.99). Illness severity demonstrated the strongest association with outcomes; each one-unit increase in APR-DRG severity was associated with higher mortality (OR 5.20), longer LOS (+3.18 days), and higher hospitalization cost (+$9,293). Complicated hospitalizations were associated with longer LOS (+5.10 days) and higher costs (+$38,211). Hospitalization costs increased significantly in 2020 compared with 2018 and remained elevated through 2022. Conclusions: Among younger adults hospitalized with GI malignancies, inpatient outcomes were most strongly associated with illness severity and payer status rather than neighborhood income. These nationally representative findings provide benchmarking data on socioeconomic patterns in inpatient outcomes for early-onset GI cancer hospitalizations.