Nutritional anemia and risk of critical illness among hospitalized patients with head and neck cancer.

e18131 Background: Patients with head and neck cancer frequently experience nutritional compromise related to tumor location, disease burden, and treatment effects, including dysphagia, mucositis, and decreased oral intake. These factors often coexist with systemic inflammation and chronic illness, contributing to impaired physiologic reserve during hospitalization. Nutritional anemia may capture this vulnerability, yet its relationship with inpatient clinical outcomes has not been well described in nationally representative data. Methods: We performed a retrospective cohort study using the National Inpatient Sample from 2016 to 2022. We reviewed adult hospitalizations with a principal diagnosis of head and neck cancer and coexisting nutritional anemia were identified using ICD-10 codes. The primary outcome was in-hospital mortality. Secondary outcomes included mechanical ventilation, length of stay, and total hospital charges adjusted to 2022 US dollars. Multivariable regression models adjusted for demographic factors, insurance status, neighborhood income quartile, comorbidity burden, and hospital characteristics. Acute in-hospital complications were not included in primary models given their likely role as intermediates along the causal pathway. Survey weights were applied to generate national estimates. Results: An estimated 189,320 hospitalizations for head and neck cancer were identified, of which 1.2 percent involved nutritional anemia. In unadjusted analyses, nutritional anemia was associated with higher in-hospital mortality. After adjustment for demographic, socioeconomic, comorbidity, and hospital characteristics, nutritional anemia was no longer independently associated with mortality. Nutritional anemia did, however, remain associated with higher odds of mechanical ventilation, longer hospital stays, and increased hospital charges. The attenuation of the mortality association after adjustment suggests that excess risk may be mediated through downstream clinical deterioration. Conclusions: Among adults hospitalized with head and neck cancer, nutritional anemia identifies patients with greater illness complexity and higher inpatient resource use. Although it was not independently associated with mortality after multivariable adjustment, nutritional anemia was associated with markers of critical illness and prolonged hospitalization. These findings support the role of nutritional anemia as a clinically meaningful marker of vulnerability and highlight the importance of early nutritional evaluation and supportive care during hospitalization.