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An Exploration of the Cost of Liver Transplantation Using the OrganOx Normothermic Machine Perfusion in Comparison to Static Cold Storage in the Canadian Setting
- Author / Creator
- Webb, Alexandria
Liver transplantation is life-saving but costly for the health care system, the patient and their caregivers. Over the last decade there has been a decrease in the available liver grafts leading to an increased use of extended criteria donors and an increase in the waitlist mortality rate. The development and use of machine perfusion have been an ongoing focus in liver transplantation research. The OrganOx machine allows for normothermic machine perfusion (NMP) of liver grafts at physiologic temperature, oxygenation, and blood pressure and flow. It allows for assessment of synthetic and metabolic function prior to transplantation. Clinical research has proven safety and feasibility of the OrganOx machine for use immediately post-procurement, after a period of static cold storage (SCS), and for rescuing liver grafts that have been deemed unsuitable for transplantation. The OrganOx machine increases liver quality, lowers transaminase injury, and increases the number of grafts available by decreasing the discard rate and rescuing grafts. The cost of the OrganOx machine must be considered in relation to the cost of transplantation. The liver transplantation process is made up of three phases: pre-transplantation, transplantation admission, and post-transplantation. The cost of each of these range widely with driving factors. Patient frailty, severity of liver disease, and overall severity of illness are key driving factors for cost.
The cost of the liver transplantation operation and cost per run of the OrganOx machine were calculated from 106 in-province procurements, 237 out-of-province procurements, and 343 liver transplantations. The total cost for in-province procurement and transplantation ranged from $30,770 to $35,659 ($CAD 2019), when considering physician billing modifiers. The total cost for out-of-province procurement and in-province transplantation ranged from $44,636 to $48,076. The cost per run of the OrganOx machine ranged from $18,593 to $20,241, when considering the variability of the exchange rate from Great British pounds sterling to Canadian dollars.
The cost of the transplantation admission was calculated from a retrospective cohort study of 59 OrganOx patients propensity score-matched to 176 SCS patients from date and time of transplant to date and time of hospital discharge. A multiple linear regression adjusting for matching, model for end-stage liver disease sodium (MELDNa) at transplant, age at transplant, and acute or chronic liver failure was completed. The mean total cost of the transplantation admission for OrganOx patients was $155,318 ($CAD 2020) compared to $119,424 for SCS patients. The mean adjusted difference was significantly higher at $32,221 (p=0.023), with the majority from the cost of the OrganOx machine during the transplantation operation ($21,673, p<0.001). The subgroup analyses support the current literature that higher costs are driven by increased severity of liver disease, severity of overall illness, and by those who died in hospital post-transplantation.
A cost-utility analysis calculated the cumulative costs, mean costs, and incremental effectiveness of a liver transplant program using SCS and the OrganOx machine (NMP) compared to a liver transplant program using SCS alone (control). A Markov model compared these two approaches with a 1-year cycle over a 5-year time horizon from the public health care payer perspective. Primary cost data and transition probabilities from a single center and health utility values from the literature were applied. Scenario analysis and probabilistic sensitivity analysis (PSA) were completed. The NMP approach is both cost-saving and cost-effective, dominating the control approach. The results remained robust in the scenario analysis. The PSA showed NMP was cost-effective 63% of the time at the conventional willingness-to-pay threshold of $50,000. The addition of NMP to a liver transplant program is both cost-savings and cost-effective with an increase in quality adjusted life years gained from the public health care payer perspective.
Overall, this thesis has shown that the addition of the OrganOx machine to a Canadian liver transplant program is cost-saving and cost-effective when compared to SCS alone. Additionally, it reduces burnout in the clinical operating room team, which will impact the societal cost of the OrganOx machine. The increased costs for implementation of this technology are substantial but an increase in the number of transplantations leads to a decrease in the number of people awaiting transplant and waitlist mortality rate. The addition of the OrganOx machine will help address the issues of supply and demand mismatch that Canadian transplantation programs are currently facing.
- Graduation date
- Fall 2021
- Type of Item
- Master of Science
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.