OBJECTIVES: This study aims to evaluate risk factors associated with increased initial hospital length of stay (LOS) and 30-day readmissions among patients with relapsed/refractory large B-cell lymphoma (R/R LBCL) treated with chimeric antigen receptor T-cell (CAR T-cell) therapy.

METHODS: A retrospective review of the medical records for patients with R/R LBCL who received CAR T-cell therapy (Jan 2016 – Jun 2022) at the University of California of San Diego (UCSD) was conducted. Between group differences were assessed by t-test and chi-square test as appropriate. Negative binomial modeling and logistic regression with backward elimination and AIC minimization methods were performed to evaluate risk factors and their impact on LOS and 30-day readmission. The analyses were adjusted for age, gender, and other demographics and clinical variables.

RESULTS: A total of 66 patients (median age, 59.5 yr; range, 23–81; axicabtagene ciloleucel [89%] and tisagenlecleucel [11%]) with mean LOS 16.74 days (SD, 12.43) were identified. 92% of patients had a known response status (complete response, 53%; partial response, 13%; refractory, 26%) while 8% had an unknown response (cutoff date Apr 15, 2023). 19 patients (29%) had an ICU admission during initial hospitalization for CAR T-cell therapy.

Significant risk factors for increased LOS (n=66) on multivariate analysis included age-adjusted HCT-CI score (IRR 1.08; 95% CI, 1.01 to 1.15; p=0.0207), thrombocytopenia grade 3-4 (IRR 1.32; 95% CI, 1.03 to 1.69; p=0.0227), and ICU admission (IRR 1.81; 95% CI, 1.39 to 2.36; p< 0.0001). For 30-day readmissions, univariate analysis revealed thrombocytopenia grade 3-4 and infection grade 3-4 as significant predictors but not in multiple logistic regression.

CONCLUSIONS: This study identified key risk factors contributing to prolonged hospital stays and 30-day readmissions in R/R LBCL patients treated with CAR T-cell therapy regardless of response status. Such findings may help healthcare providers better develop strategies to optimize patient care and resource utilization.