Factors Associated with Increased Healthcare Utilization Within 30 and 90 Days Post-Discharge of CAR-T Cell Therapy in Patients with R/R LBCL.

Background/Objectives: CAR T-cell therapy is a highly efficacious therapy option for relapsed/refractory (R/R) large B-cell lymphoma (LBCL), but its widespread use is currently limited by safety concerns and high healthcare costs. Methods: We evaluated 66 patients with R/R LBCL treated with tisagenlecleucel or axicabtagene ciloleucel between 2016 and 2022 at a single institution to identify factors associated with increased healthcare utilization. Results: The median age of our cohort was 59.5 years, with 22.7% over the age of 70. The median length of stay (LOS) during the initial hospitalization was 12 days (range, 7-62 days). Longer initial hospital LOS was linked to higher age-adjusted HCT-CI score (IRR 1.08; 95% CI, 1.01 to 1.15; p = 0.0203), thrombocytopenia grade 3-4 (IRR 1.32; 95% CI, 1.07 to 1.63; p = 0.0091), and first ICU admission (IRR 1.81; 95% CI, 1.37 to 2.38; p < 0.00001). Thirty- and 90-day readmission rates post-discharge after receiving CAR T-cell therapy were 21.2% and 28.8%, respectively. Multiple readmissions within 90 days after initial hospital discharge were observed in 15% of patients. Longer 30-day readmission LOS was linked to initial hospital LOS (IRR 1.23; 95% CI, 1.11 to 1.35; p < 0.0001) but outpatient follow-up was associated with shorter 30-day readmission LOS (IRR 0.43; 95% CI, 0.26-0.69; p = 0.0005). Factors associated with longer 90-day readmission LOS included a greater number of ER visits within 60 days of CAR T-cell therapy (IRR 3.10; 95% CI, 2.15-4.46), prior 30-day readmission LOS (IRR 1.35; 95% CI, 1.14-1.60), and SUVmax at Day 30 (IRR 1.06; 95% CI, 1.03-1.09) (all p-values < 0.0001). Conclusions: Our findings identify key clinical and utilization variables associated with initial and repeat hospitalizations post-CAR T-cell therapy, emphasizing the need for targeted interventions to reduce readmissions and optimize post-discharge care.