Hospital Length of Stay and Associated Factors in Patients with Oral Cavity Cancer in Germany: A Retrospective...

Oral cavity cancer is a clinically relevant subgroup of head and neck malignancies and is associated with substantial treatment burden and healthcare utilization. Hospital length of stay (LOS) is an important indicator of inpatient resource use and complexity of care, yet large multicenter data from Germany are limited.

This retrospective multicenter analysis used anonymized inpatient administrative data from 49 German hospitals; eligible oral cavity cancer hospitalizations were contributed by 34 of these hospitals. Adult inpatient hospitalizations (≥18 years) with malignant neoplasms of the oral cavity, defined using ICD-10-GM codes C00-C06, recorded between January 1 2019 and 31 December 2024 were included. The primary outcome was hospital LOS in days. Multimorbidity was quantified using the van Walraven-weighted Elixhauser Comorbidity Score. Prolonged hospitalization was defined as LOS ≥ 7 days and LOS ≥ 14 days. Associations between demographic, clinical, and treatment-related variables and LOS were examined using multivariable Poisson regression models. Because overdispersion was present, a negative binomial mixed model was additionally fitted as a sensitivity analysis. To account for inter-hospital variability, hospital was included as a random intercept in all multivariable models. Associations with prolonged LOS were analyzed using multivariable logistic regression models. All analyses were performed at the hospitalization level.

A total of 3957 inpatient hospitalizations for oral cavity cancer were included. Mean age was 65.6 years, and 66.2% of hospitalizations involved male patients. The median LOS was 6 days (interquartile range [IQR] 3-13; mean 10.2 days, standard deviation 11.8). Overall, 49.4% of hospitalizations had an LOS ≥ 7 days and 23.5% had an LOS ≥ 14 days. Older age, particularly >80 years, and higher comorbidity burden were associated with longer LOS (adjusted Poisson rate ratio [RR] for age > 80 years 1.17, 95% CI 1.13-1.21; high comorbidity burden RR 1.58, 95% CI 1.54-1.63). Several treatment-related variables, including surgical procedures in the oral and facial region, lymphatic system operations, blood transfusions, and complex intensive care treatment, were associated with prolonged hospitalization (e.g., blood transfusion RR 1.80, 95% CI 1.76-1.85; complex intensive care RR 1.70, 95% CI 1.65-1.75). Chemotherapy-related hospitalizations were associated with shorter LOS.

LOS varied substantially across inpatient hospitalizations for oral cavity cancer in Germany. Older age, higher comorbidity burden, and markers of more complex inpatient treatment were associated with extended hospital stay. These findings may help identify hospitalizations at increased risk of prolonged LOS and inform inpatient planning and resource allocation.