Beyond Preventable Admissions: Rethinking Unplanned Hospitalization as a Patient-Centered Quality Indicator in Modern Oncology

Background: Unplanned hospitalization during systemic anticancer therapy is increasingly used to measure treatment safety, healthcare utilization, and oncology service quality. However, hospital admission is a heterogeneous clinical outcome that may reflect potentially preventable deterioration, unavoidable complications, or appropriate escalation of care. Treating these circumstances as equivalent may lead to misleading assessments of clinical performance and inappropriate quality-improvement priorities. Objective: To critically examine the determinants, preventability, and interpretation of unplanned hospitalization among adults receiving systemic anticancer therapy and propose a patient-centered approach to its evaluation. Evidence synthesis: This critical narrative review draws on observational studies, systematic reviews, randomized clinical trials, professional guidelines, and research on supportive care delivery. Available evidence identifies treatment toxicity, disease-related complications, functional vulnerability, comorbidity, symptom burden, and healthcare accessibility as interacting determinants of acute care use. Estimates vary considerably across populations and study designs. Electronic patient-reported outcome monitoring and geriatric assessment-guided interventions improve selected clinical outcomes, but reductions in hospitalization are not consistently demonstrated. Administrative definitions of preventability may also misclassify urgent or clinically necessary encounters. Alternative outpatient and home-based models offer opportunities to reduce conventional hospital utilization, although effectiveness depends on patient selection, service capacity, and implementation context. Conclusions: Hospitalization frequency alone is an insufficient measure of cancer care quality. A more clinically meaningful approach should distinguish preventable deterioration from necessary admission and incorporate clinical severity, symptom trajectories, modifiable risk factors, healthcare accessibility, and patient preferences. Future research should prioritize standardized outcome definitions, longitudinal risk assessment, and pragmatic evaluation of interventions that improve patient-centered outcomes without compromising timely acute care.