High Healthcare Resource Utilization and Cost for PTLD Patients Following Kidney Transplants
Authors: Hart A , Ahn Y S , Watson C , Skeans M , Barlev A , Thompson B , Dharnidharka VR 
Published: February 2021

Background: Post-transplant lymphoproliferative disease (PTLD) is a rare and aggressive disease with high mortality rates, and may have substantial healthcare resource utilization (HRU) and cost.

Objectives: To describe the HRU and Medicare paid amounts up to 3 years after kidney transplants for PTLD patients and for all kidney transplant patients.

Methods: The United States Renal Data System (USRDS) is a national data system that collects, analyzes and distributes information about chronic kidney disease (CKD) and end-stage renal disease (ESRD) in the United States. It is a claim dataset that provides Medicare paid amounts and HRU for these patients, including their kidney transplants. Patients are Medicare-eligible for 3 years after a successful kidney transplant.

The Scientific Registry of Transplant Recipients (SRTR) is a national data system that reports data from transplant centers on all solid organ transplants in the US, including data on malignancies after transplants, including PTLD.

The USRDS data was used to identify Medicare-covered kidney transplant recipients from 2007 until 2016. SRTR malignancy data were used to obtain patients with a PTLD diagnosis, which was linked to the USRDS. Patients had to have a USRDS claim on the date of transplantation. Only patients enrolled in Medicare Part A and Part B fee-for-service were included. Solitary kidney re-transplants were included but not multi-organ transplants, due to a potential difference in HRU and cost in the latter. Medicare Part A (inpatient, outpatient, home health, hospice, skilled nursing) and B HRU and paid amounts were tabulated for up to 3 years' post-transplant. The year post-transplant was calculated using 365.25 days per year following the kidney transplant. For example, recipients with a PTLD diagnosis any time within 365.25 days following their kidney transplant were considered a PTLD patients within 1-year post-transplant. A per person-year (PPY) was computed to standardize costs. Patients were censored at loss of Medicare eligibility or death or at the end of 3-year post-transplant.

Results: A total of 83,818 Medicare-covered kidney transplants were included in this study with a mean age of 51.55 (SD: 15.11) at transplant and 60.77% male. Average paid amount from transplant to 1-year post-transplant was $83,546 PPY, with approximately two-thirds of the cost coming from inpatient hospitalization. For year 2 and 3 post-transplant, the average paid amount was $26,148 PPY and $25,326 PPY, respectively, with similar cost coming from inpatient and Part B (~39% each). Among these kidney transplant recipients, 281 transplant recipients had PTLD while Medicare-eligible with an average age of 53.98 (SD: 19.19) years at transplant and 67.97% male. Median time from transplant to PTLD diagnosis was 1.02 years (IQR: 0.60-1.93 years).

For patients who were diagnosed with PTLD within the first year after transplant (n=139), average paid amount from date of the first PTLD diagnosis to 1-year post-transplant was $222,336 PPY, with approximately two-thirds of the cost from inpatient hospitalization. Of these patients who survived or were eligible in year 2 (n=94) and 3 (n=64), the average cost was $60,981 PPY and $36,118 PPY, respectively. For patients who were diagnosed with PTLD in the second year after transplant (n=81), average paid amount in year 2 post-transplant was $203,374 PPY with approximately 60% coming from inpatient hospitalization. Year 3 post-transplant cost for these PTLD patients who survived or were eligible (n=59) was $58,879 PPY. For patients who were diagnosed with PTLD in the third year after transplant (n=61), average paid

amount in year 3 post-transplant was $211,941 PPY with 68% coming from inpatient hospitalization.

Conclusions: PTLD is associated with substantial HRU and cost (&gt;$200k PPY in the year diagnosed), regardless of the year diagnosed post-transplant, while patients without PTLD and patients who haven't developed PTLD yet had a cost of ~$83k PPY in year 1, and ~$26k PPY for year 2 and 3 post-transplant.

Disclosures

Ahn: Medtronic: Current equity holder in publicly-traded company; Bristol-Myers Squibb: Research Funding. Watson:Atara Biotherapeutics: Current Employment, Current equity holder in publicly-traded company. Skeans:Bristol-Myers Squibb: Research Funding; Astellas: Research Funding; Atara Biotherapeutics: Research Funding. Barlev:Atara Biotherapeutics: Current Employment, Current equity holder in publicly-traded company. Thompson:Atara Biotherapeutics: Research Funding; Bristol-Myers Squibb: Research Funding. Dharnidharka:Atara Biotherapeutics: Consultancy, Honoraria, Research Funding; CareDx: Honoraria, Research Funding, Speakers Bureau.