Cohort Identification and Outcomes
A cohort of patients aged 1-25 years, with ALL who received CAR-T therapy between Oct 2016 and Dec 2021 in the United States was identified. CAR-T product administration was confirmed with use of ICD-10 codes for non-specific or specific CAR-T products: XW033C3, XW033C7, XW033J7, XW043C3, XW043C7, XW043J7; or the CPT code for the administration itself: 0540T. ALL diagnosis was confirmed based on ICD-10 diagnostic codes: C91.00, C91.01, C91.02. To be included, individuals were required to have had continuous insurance coverage for 30 days prior to and 60 days after CAR-T product administration, unless patient death occurred during this time period. This time frame was chosen to include the majority of therapy-related complications while avoiding variation from pre-leukapheresis salvage therapies and potential post-infusion relapse therapies.
Outcomes of interest included both cost and utilization of care. Here, cost is defined as total reimbursement paid by the commercial payer. Inpatient cost corresponds to claims with a place of service at an inpatient hospital, and outpatient cost correspond to a place of service at an office or hospital-based outpatient clinic. Utilization was summarized as inpatient days, inpatient encounters, and outpatient encounters. An inpatient encounter corresponded to claims with an inpatient place of service with distinct start and end dates, and an outpatient encounter was defined as a unique physician claim with the place of service either being an office or hospital-based outpatient clinic.