In the United States, three people pass away on average every day while awaiting a liver transplant, costing about 1,200 lives in 2021. Over the past ten years, there have been significant changes to liver allocation policy. Researchers recently looked into these policies and discovered that despite the modifications, geographic inequality still exists. The authors suggest distributing livers in a more effective and fair manner.
In the transplant community, more organ sharing is thought to reduce geographic disparities in availability to organs (such as inter-geographical variation in transplant rates, patient survival rates, waiting times, and offers). In order to assess allocation rules that differ from the present and proposed policies, researchers created a model based on roughly 40 medical parameters of patients and donors. This allowed them to decide whether there was a better alternative.
The model correctly predicts how a change in policy would affect a patient’s likelihood of accepting an organ offer. They used information from the Scientific Registry of Transplant Recipients, which contains data on all donors, applicants on the waiting list, and transplant recipients in the United States.
In order to organize a national transplant network and maximize the use of scarce donor organs for transplants, the U.S. government established the Organ Procurement and Transplantation Network (OPTN) in 1984. Since 1986, OPTN’s operations have been under the management of the United Network for Organ Sharing, a nonprofit private organization. The Final Rule, which was enacted in 1998 by the U.S. Department of Health and Human Services and specifies that policies shall not be based on the candidate’s location of residency, is a crucial regulatory framework governing organ transplantation. Disparities in organ access, however, have been a significant problem for more than 20 years. The board of OPTN established a strategy plan in 2012 that called for minimizing geographic inequities in transplant access.
For the purposes of organ allocation, the United States is divided into 11 geographic regions, consisting of 58 Donation Service Areas (DSAs). A DSA-based allocation policy was in place for 30 years, from 1989 to February 2020, when it was replaced by the Acuity Circles policy, which provides a one-size-fits-all variant of broader sharing.
In the transplant community, broader organ sharing is believed to mitigate geographic inequity (e.g., inter-geographical variation in the transplant rates, patient survival rates, waiting times, offers) when considering access to organs. In this study, researchers developed a model based on about 40 medical characteristics of patients and donors to analyze allocation policies that differ from current and proposed policies, and to determine whether a better alternative exists.
The model accurately predicts the change in a patient’s organ-offer acceptance probability due to a change in policy. They used data from the Scientific Registry of Transplant Recipients, which includes information on all donors, wait-listed candidates as well as U.S. transplant recipients.
Based on their model’s predictions, the researchers conclude that broader sharing in its current form (i.e., as part of Acuity Circles) may not be the best strategy to balance geographic equity and efficiency. Instead, they suggest that a policy that equalizes the ratio of deceased donors to waiting list patients across geographic regions would work better in achieving geographic equity at the lowest tradeoff in efficiency.
“Recent policies are moving toward broader sharing in principle, but the current Acuity Circles policy leads to even lower efficiency,” explains S. Raghavan, Professor of Management Science and Operations Management at UMD, who coauthored the study. “A customized approach involving equalizing the supply-to-demand ratios across the geographic regions of the country is a better option.”
“Our model can be used to provide more accurate policy evaluations to decision makers,” says Liye Ma, Associate Professor of Marketing at UMD, who coauthored the study.