Geographic variation in outcomes and resource utilization among U.S. hospitalizations for tumor lysis syndrome.

e13718 Background: Tumor lysis syndrome (TLS) is a life threatening oncologic emergency. Geographic differences in U.S. hospital systems may influence patient outcomes and cost, but national comparisons remain limited. Methods: We analyzed 73,975 weighted TLS hospitalizations in the Nationwide Inpatient Sample, stratified by hospital region (Northeast, Midwest, South, West). Categorical outcomes were compared using Pearson chi square tests, and continuous variables were evaluated with Welch ANOVA and Games–Howell post hoc testing. Results: In-hospital mortality was highest in the Northeast at 26.1% compared with 21.5% in the Midwest, 21.5% in the South, and 20.2% in the West (p < 0.001). Congestive heart failure was most common in the Northeast and Midwest (19.0% and 19.3%, respectively) and lowest in the West (13.7%, p < 0.001). Acute kidney injury was frequent in all regions but peaked in the Northeast and Midwest (68.4% and 69.1%) and was lowest in the West (61.3%, p < 0.001). Sepsis occurred in roughly one quarter of admissions with slightly higher rates in the Northeast and West (p = 0.001), and organ failure was most common in the Midwest (78.8%) and least common in the West (72.9%, p < 0.001). Mechanical ventilation ranged from 15.9% in the Northeast to 13.9% in the West (p < 0.001), and vasopressor use ranged from 6.9% in the Northeast to 4.2% in the West (p < 0.001). Electrolyte derangements showed consistent geographic gradients: hyperkalemia (31.3% Midwest vs. 25.3% West), hypocalcemia (12.9% Midwest vs. 9.7% Northeast), hyperphosphatemia (25.3% Midwest vs. 20.6% Northeast), and hyperuricemia (16.5% Midwest vs. 10.3% Northeast) all peaked in the Midwest (all p < 0.001). Frailty or malnutrition/sarcopenia was highest in the Midwest (24.5%) and lowest in the South (20.4%, p < 0.001). Mean age was greatest in the Northeast (61.6 years) and lowest in the West (55.7 years, p < 0.001). Length of stay was longest in the Northeast (15.4 days) and shortest in the Midwest (13.2 days, p < 0.001). Total hospital charges were highest in the West (mean $295,043) despite this region having the youngest patients and the lowest comorbidity burden, and lowest in the Midwest ($188,425, p < 0.001). The Charlson Comorbidity Index was highest in the Midwest (6.99) and lowest in the West (6.32, p < 0.001). Conclusions: The Northeast experiences the highest mortality, longest hospital stays, and heavy critical care utilization, while the Midwest carries the greatest burden of chronic kidney disease, metabolic complications, and frailty but the lowest costs. The West, despite younger and less comorbid patients, incurs the highest charges. These findings highlight the need to investigate regional practice patterns and system factors that may underlie these disparities and to target quality improvement efforts accordingly.