Hospitalized Patients with Oral Cavity Cancer and Ulcerative Mucositis: Implications for Key Cost Drivers and Disparities

Background: Cancer treatment-induced ulcerative mucositis (UM) is a debilitating toxicity in patients with cancers of the lip, oral cavity, and pharynx (CLOP). This study evaluated the association of chemotherapy-induced (CT-UM) and radiotherapy-induced ulcerative mucositis (RT-UM) with burden of illness (BOI), focusing on hospital length of stay (LOS) and total charges, and examined disparities in outcomes. Methods: This retrospective cohort study analyzed 2019 National Inpatient Sample (NIS) data. Adult patients (≥18 years) hospitalized with CLOP (ICD-10-CM C00–C14) undergoing inpatient surgery, chemotherapy, or radiotherapy were included. CT-UM (K12.31) and RT-UM (K12.33) were identified as secondary diagnoses. Survey-weighted generalized linear models (negative binomial for LOS; gamma for charges) adjusted for demographics, comorbidities (Elixhauser score), insurance, income, and Diagnosis-Related Groups (DRG; surgical vs. medical) were used. Results: Among 59,710 weighted CLOP hospitalizations, 820 had CT-UM and 1010 had RT-UM. Patients with UM were younger and had varying comorbidity burdens. Unadjusted analyses showed prolonged geometric mean LOS for CT-UM (5.66 vs. 3.81 days, p < 0.001) and RT-UM (4.95 vs. 3.81 days, p = 0.001), with lower total charges ($48,645 and $42,938 vs. $56,267). Multivariable analyses confirmed RT-UM was associated with increased LOS (adjusted coefficient 1.33, 95% CI 1.14–1.55) but lower charges (0.67, 95% CI 0.56–0.81). In patients >50 years, CT-UM showed stronger effects (LOS 1.80, 95% CI 1.49–2.15; charges 0.79, 95% CI 0.65–0.98). Significant disparities were observed: females, Black and Hispanic patients, and Medicaid beneficiaries experienced greater BOI (prolonged LOS and/or higher charges in subgroups). Associations persisted in DRG- and procedure-stratified sensitivity analyses, suggesting treatment interruptions as a key driver. Conclusions: Ulcerative mucositis in hospitalized CLOP patients is associated with prolonged LOS but lower charges, likely due to treatment modifications, and disproportionately affects vulnerable populations. These findings highlight the need for proactive oral care protocols, multidisciplinary integration, and equity-focused interventions to reduce the burden of this toxicity and improve cancer treatment outcomes.