Inpatient mortality across gastrointestinal malignancies by hospital structural characteristics in the United States, 2018–2022.

e16353 Background: Inpatient mortality among gastrointestinal (GI) cancer hospitalizations is often attributed to tumor biology and disease severity. National data describing the relative contribution of hospital structural characteristics to acute inpatient outcomes across GI malignancies remain limited. Methods: A serial cross-sectional analysis was conducted using the 2018–2022 Healthcare Cost and Utilization Project National Inpatient Sample. Adult hospitalizations with a principal diagnosis of esophageal, gastric, colorectal, hepatocellular, or pancreatic cancer were identified. Outcomes included in-hospital mortality (primary), length of stay (LOS), and hospitalization cost estimated using cost-to-charge ratios. Hospital structural characteristics examined included teaching status, bed size, geographic region, and urban–rural classification. National estimates accounted for survey weighting, clustering, and stratification. Survey-weighted multivariable logistic regression identified factors independently associated with in-hospital mortality, adjusting for cancer subtype, demographics, payer, neighborhood income quartile, hospital characteristics, and calendar year. Results: From 2018–2022, 214,740 unweighted GI cancer hospitalizations represented an estimated 1,073,700 hospitalizations nationally. Overall weighted in-hospital mortality was 4.03%. After adjustment, admission to a teaching hospital was associated with lower odds of in-hospital death compared with non-teaching hospitals (adjusted odds ratio [aOR] 0.56, 95% CI 0.51–0.63). Large hospitals also demonstrated lower mortality compared with small hospitals, while no significant difference was observed for medium hospitals. Geographic variation persisted, with lower adjusted mortality in the Midwest and South compared with the Northeast. By comparison, adjusted mortality differences across major GI cancer subtypes were smaller than those observed across hospital structural characteristics. Teaching hospitals demonstrated longer LOS but lower mortality following acute complications, consistent with differences in rescue capacity rather than complication incidence. Conclusions: Among GI cancer hospitalizations, inpatient mortality varied more by hospital structural characteristics than by cancer subtype. Teaching status, hospital size, region, and urban–rural context were associated with differences in survival independent of tumor site. These nationally representative findings provide benchmarking data on the institutional context of inpatient mortality in gastrointestinal oncology.