Composition and influencing factors of malnutrition management costs among gastrointestinal cancer patients with chronic comorbidities.

OBJECTIVE: Malnutrition is highly prevalent among patients with gastrointestinal (GI) malignancies and is further aggravated by comorbid chronic conditions, substantially increasing healthcare expenditures. However, few studies have dissected the cost composition of malnutrition management or identified its determinants in this comorbid population. This study aimed to characterize the composition of malnutrition management costs and explore their influencing factors among GI cancer patients with comorbidities. METHODS: A retrospective cohort study was conducted at a tertiary hospital in Yinchuan, China. A total of 418 GI cancer inpatients with at least one chronic comorbidity, diagnosed with malnutrition between October 2024 and October 2025, were enrolled. Data on demographic characteristics, disease profiles, nutritional treatment modalities, and itemized hospitalization costs were extracted from the Hospital Information System (HIS). Malnutrition management costs were categorized into seven domains. Multivariable generalized linear models (Gamma distribution, log link) were fitted to identify independent cost determinants. RESULTS: The median total malnutrition management cost was USD 833.61 (IQR: 386.21-1,391.72). Pharmaceutical cost constituted the largest share (57.35%), followed by laboratory cost (18.32%). Generalized linear model analysis showed that length of hospital stay was significantly positively associated with total cost: patients hospitalized for 10-19 days and ≥20 days incurred 2.06-fold (β = 0.722, P < 0.001) and 3.35-fold (β = 1.210, P < 0.001) higher costs, respectively. Surgery (β = 0.263, P = 0.005), combined parenteral and enteral nutrition (β = 0.945, P < 0.001), and total parenteral nutrition (β = 0.929, P < 0.001) were also significantly positively associated with total costs. Comorbidity burden (≥3 chronic diseases: β = 0.247, P = 0.003; endocrine and metabolic diseases: β = 0.235, P = 0.001) and moderate malnutrition (β = 0.211, P = 0.010) showed significant positive associations. Conversely, radiotherapy (β = -0.593, P < 0.001) and respiratory comorbidities (β = -0.295, P < 0.001) were significantly negatively associated with total costs. CONCLUSION: Pharmaceutical cost dominates malnutrition management costs in GI cancer patients with comorbidities. Hospital stay duration, nutritional intervention intensity, and comorbidity burden were independently associated with cost variability. These findings may inform clinicians and health policymakers in efforts to optimize resource allocation.