Risk Factors for 30-Day and 90-Day Readmission in Patients with Tumor Lysis Syndrome: A Nationwide Analysis
Authors: Musleh Ud Din Saba , Park Kyeeun , Jones Can 
Published: December 2024

Background:
Tumor lysis syndrome (TLS) is a critical oncological emergency predominantly associated with hematological malignancies. Despite advancements in TLS management, patients frequently experience high readmission rates, underscoring the need to identify and address risk factors contributing to these readmissions.
Methods:
We conducted a retrospective analysis of the 2018-2019 Nationwide Readmission Database to evaluate 30 and 90-day readmission rates along with associated risk factors in adult patients (&gt;18 years) after an initial index admission with TLS. Patients were identified using ICD-10-CM codes. National estimates were calculated using discharge weights, and categorical variables were compared using the chi-square test. Univariate and multivariable hierarchical regression models were employed to determine odds ratios (ORs) for readmission risk factors.
Results:
During the study period, a total of 30,437 patients with TLS were admitted. The mean age was 60.8 years, and 37.2% were female. Comorbidities included diabetes (22.7%, n=6,920), hypertension (55.2%, n=16,804), and chronic kidney disease (23.0%, n=7,002). Admission diagnoses were acute kidney injury (AKI) (66.7%, n=23,312), acute respiratory failure (29.3%, n=8,923), and sepsis (16.5%, n=5,022). 11% (n=3,379) of the admitted patients required mechanical ventilation.
Hematological cancers (65.0%, n=19,793) were the predominant malignancies associated with TLS, particularly non-Hodgkin lymphoma (29.4%, n=8,950), acute myeloid leukemia (AML) (18.4%, n=5,602), acute lymphoblastic leukemia (11.5%, n=3,498), and multiple myeloma (6.8%, n=2,070). Solid tumors were less frequently associated (10.6%, n=3,211), with lung cancer being the most common (5.2%, 1,585), followed by colorectal (1.5%, n=457) and breast (1.4%, n=426).
23.3% (n=7,092) of admitted patients died during the index admission. Among those patients who were discharged, readmission rates were notably high, with 28.8% (n=6,727) of patients readmitted within 30 days and 38.9% (n=9,072) within 90 days. Leading causes for 30-day readmission included sepsis (15.1%, n=1,016), neutropenia (5.1%, n=343), repeat TLS (3.4%, n=229), AKI (3.3%, n=222), and chemotherapy-induced pancytopenia (3.2%, n=215). After adjusting for demographics, AML and multiple myeloma increased the risk of 30-day readmission indicated by AML (OR 1.13; 95% CI 1.01-1.22; p=0.0001) and multiple myeloma (OR 1.16; 95% CI 1.04-1.28; p=0.007). Other types of cancers did not affect the risk of admission significantly. AKI during the index admission was also associated with higher 30-day readmission rates (OR 1.1; 95% CI 1.02-1.15; p=0.007), while mechanical ventilation was not (p=0.27).
Conclusion:
Patients with TLS exhibit substantial readmission rates, particularly those with AML and multiple myeloma. AKI during the index admission was a significant risk factor for 30-day readmission. These findings highlight the need for improved management strategies and follow-up care to reduce readmissions and improve patient outcomes in this high-risk group. Future studies should focus on targeted interventions to mitigate these risks and enhance the quality of care for TLS patients.