Collaborative Intelligence: Mason Professors and Inova to Study Transplant Organ Allocation
by Jocelyn Rappaport
When School of Public Policy Professor Naoru Koizumi read about the complex disparities of organ transplantation, she called on her colleagues at Mason and Inova Health System to develop a proposal to study the problem in depth. The team's primary interest is to learn how an optimal organ allocation system 
developed using systems science technologies can achieve more equitable and efficient organ allocation.
The team recently received a National Institute of Health (NIH) grant for its Geographic Information System (GIS)/Simulation Liver Allocation Project.
"This is a great team, and I am proud that NIH found the significance of this project to be very high," says Koizumi, principal investigator of the research. This is not the first time an NIH grant has allowed her to pursue research involving health care and optimization techniques. Not long ago, Koizumi conducted a study of Delaware mental health facilities that was aimed at reducing congestion in hospitals.
Koizumi knew that choosing the perfect experts for the team was essential to obtain the grant that would allow the research. One such expert is Chun-Hung Chen, whose extensive knowledge of efficient simulation prompted Koizumi to ask him to join the effort.
"It is exciting to join such an extraordinary research team," says Chen, professor of systems engineering and operations research with Mason's Volgenau School of Information Technology and Engineering. "It is also an honor and a rare occurrence for a team to receive a competitive NIH grant on the first submission."
Simulation will allow the team to analyze the effect of changes in allocation rules. The team will use a new technique, Optimal Computing Budget Allocation, which was invented by Professor Chen, to dramatically enhance simulation efficiency. Chen says that as a result, more allocation rules can be simulated and a better decision can be determined in a shorter time.
"We also needed someone knowledgeable about clinical research, liver disease, and liver transplantation, as well as being connected to the health care system and information," adds Koizumi. She credits Roger Stough, Mason vice president for research and economic development, and Jim Olds, director of Mason's Krasnow Institute for Advanced Study, for introducing her to Dr. Zobair Younossi, vice president of research with Inova Health System and executive director of the Center for Liver Diseases at Inova Fairfax Hospital. Younossi received a BA in biology from Mason in 1984.
"Over the past decade, Mason and Inova have had superb collaborative research projects," says Younossi. These successes led to a formal partnership between Mason and Inova, and in 2009, Inova provided Mason $1 million to establish the Mason–Inova Health System Life Sciences Research Collaboration Fund.
Even before being awarded the NIH grant, Koizumi had found that organs for transplantation are scarce worldwide. According to the United Network for Organ Sharing, more than 107,000 people in the United States alone are waiting for organ transplants.
She has learned that many factors contribute to the scarcity, but one of the most significant reasons likely has to do with where a transplant candidate resides. This factor may be in part due to how close a candidate lives to a transplantation center. The study of a transplant candidate's location in relation to allocation is where Nigel Waters, professor with Mason's Department of Geography and Geoinformation Science and director of Mason's Center of Excellence for
Geographic Information Science, will be valuable, says Koizumi.
"I met Professor Waters at a GIS Environmental Systems Research Institute annual conference a few years ago," recalls Koizumi. "His specialty in transportation networks and medical GIS is perfect for this project."
Waters notes, "Geographers are fond of telling others that ‘Geography Matters.' Put simply, this means that when seeking medical treatment where you live matters." He says with this research he wants the location of liver transplant candidates to have as little influence as possible on the treatment they receive.
According to Koizumi's research, more than 80 percent of organ transplants are of livers and kidneys. Disparities in organ allocations may be an important issue, irrespective of the type of organ. Nevertheless, the issue is most disputed in liver transplants. Current studies of the organ transplantation system suggest disparities in terms of race, socioeconomic status, insurance type, and the location of a candidate's residency. While these disparities tend to coexist, disparity associated with candidates' locations or "geographical disparity" is the most prevalent according to existing research.
The proposed study by the collaborative team seeks to assess the potential source of these disparities.
"This is a multi-objective optimization problem in which two or more policy goals could exhibit trade-off relationships," says Koizumi. The team will develop an analytical framework for optimizing organ allocation and boundary creation by applying innovative techniques involving discrete event simulation and GIS-based mapping.
Koizumi explains that in the current system, livers from deceased donors are allocated in accordance with a complex algorithm involving factors such as a candidate's urgency level, human leukocyte antigen, time on the waiting list, and location of residence. In addition, candidate residency is important in the current algorithm because a candidate living within the United Network for Organ Sharing region or the "allocation boundary" in which the liver is harvested receives priority.
"We are interested in investigating the role this allocation boundary plays in receiving a transplant and whether geographical disparity disappears if these boundaries change or disappear," says Koizumi.
As a final product of the research, the team intends to provide policymakers with an interactive GIS-based open simulation web page for visualizing geographical boundaries of organ distribution areas, including important consequences of employing such an allocation and boundary system.
Initial data and research will focus on adult liver transplants, although Koizumi says that appropriate modifications could be made to establish an equivalent framework for pediatric transplants.