Predictors of mechanical ventilation in metastatic cancer hospitalizations: A National Inpatient Sample study.

11044 Background: Invasive mechanical ventilation (MV) represents a major escalation of supportive care in metastatic cancer and is consistently associated with high short-term mortality in prior observational cohorts. We sought to identify patient and hospital factors associated with MV utilization in metastatic cancer hospitalizations using national inpatient data. Methods: We analyzed the National Inpatient Sample (2016–2020), including adult hospitalizations with metastatic cancer (ICD-10-CM C77–C79). MV was identified using ICD procedure codes. Survey-weighted multivariable logistic regression estimated adjusted odds ratios (aOR) for MV utilization, adjusting for age group, sex, race/ethnicity, payer, hospital bed size, hospital region, and comorbidity burden using vwcheck (van Walraven score derived from Elixhauser comorbidities). Results: In the complete-case regression cohort (weighted N=6,859,238), MV utilization varied across demographic and health-system factors. MV was less likely with older age (≥65 vs 18–44: aOR 0.80, 95% CI 0.75–0.87) and in females (aOR 0.96, 95% CI 0.93–0.99). Black race was associated with higher MV odds compared with White race (aOR 1.18, 95% CI 1.13–1.23). Compared with Medicare, Medicaid (aOR 1.08, 95% CI 1.01–1.14) and self-pay (aOR 1.17, 95% CI 1.05–1.30) had higher MV odds. MV was more likely in medium vs small hospitals (aOR 1.08, 95% CI 1.03–1.14) and large vs small hospitals (aOR 1.08, 95% CI 1.03–1.13). Regional variation persisted (South vs Northeast: aOR 1.11, 95% CI 1.06–1.17; West vs Northeast: aOR 1.07, 95% CI 1.01–1.13). Higher vwcheck was strongly associated with MV (aOR 1.07 per unit). Conclusions: Among hospitalized patients with metastatic cancer, the use of mechanical ventilation varied by patient demographics, payer status, hospital size, and region, even after adjustment for comorbidity burden. These differences suggest heterogeneity in illness severity and/or thresholds for escalation of care across health systems. Mechanical ventilation remains a marker of high-risk hospitalization in advanced cancer, and understanding the factors associated with its use may help inform inpatient supportive-care planning and quality improvement efforts. Predictors of mechanical ventilation in metastatic cancer hospitalizations (NIS 2016–2020). Predictor Adjusted OR (95% CI) p-value Age ≥65 vs 18–44 0.80 (0.75–0.87) <0.001 Female vs male 0.96 (0.93–0.99) 0.01 Black vs White 1.18 (1.13–1.23) <0.001 Medicaid vs Medicare 1.08 (1.01–1.14) 0.02 Self-pay vs Medicare 1.17 (1.05–1.30) 0.004 Medium vs small hospital 1.08 (1.03–1.14) 0.002 Large vs small hospital 1.08 (1.03–1.13) 0.001 South vs Northeast 1.11 (1.06–1.17) <0.001 West vs Northeast 1.07 (1.01–1.13) 0.01 van Walraven score (per unit) 1.07 (1.06–1.08) <0.001