Recovery Act funding reveals disparities, helps craft new distribution models
By Erin Fults
June 8, 2011
During his most recent hospital stay, Reginald Baker received bad news from his doctor.
Recovery Act Investment: “Reducing Geographic Disparity in Transplant Access: Clinical and Economic Impact”; Krista L. Lentine; Saint Louis University; 2009: $500,000 (1RC1DK086450-01); 2010: $500,000 (5RC1DK086450-02). Funded by the NIH Office of the Director and administered by the National Institute of Diabetes and Digestive and Kidney Diseases.
Publications listing this Recovery Act Investment as providing grant support: Axelrod DA, et al. The interplay of socioeconomic status, distance to center, and interdonor service area travel on kidney transplant access and outcomes. Clinical Journal of the American Society of Nephrology, 2010; 5(12):2276–2288.
Salvalaggio PR, et al. The interaction among donor characteristics, severity of liver disease, and the cost of liver transplantation. Liver Transplantation, 2011; 17(3):233–242.
Axelrod DA, et al. The economic implications of broader sharing of liver allografts. American Journal of Transplantation, 2011;11(4):798–807.
Participating investigators include: Krista Lentine, M.D., and Mark Schnitzler, Ph.D., at Saint Louis University; Sommer Gentry, Ph.D., at the United States Naval Academy; David Axelrod, M.D., at Dartmouth College; Dorry Segev, M.D., at the Johns Hopkins University; and Paolo Salvalaggio, M.D., at the University of Washington.
Over many years, his kidneys had gradually lost their ability to function, and now he would need a transplant. Reginald’s doctor said he would be added to a transplant list, but the waiting period for a kidney could be years. Reginald would be joining the approximately 80,000 people who are awaiting a kidney, while the annual number of transplants peaks at only about 17,000.
Reginald was especially surprised to learn that one of the factors adding the most time to his wait for a new kidney wasn’t his blood type or the severity of his disease but, rather, his geographical location. The closest transplant center to where Reginald lived served the large metropolitan region of the San Francisco Bay Area. His doctor explained that the area faced a particularly severe organ shortage due to the number of residents in need of transplants. Smaller towns in the Midwest, for example, have less competition for organs and are better supplied with kidneys for transplantation.
Reginald didn’t have the resources or the health to relocate himself and his family or to travel far from his home and his hospital to try to improve his chances of getting a kidney. He would just have to wait and hope.
ARRA May Help Improve Organ Allocation
Dr. Krista Lentine, associate professor of medicine at Saint Louis University, is addressing the plight of the thousands of Americans awaiting life-saving organs, particularly kidney and liver transplantations. With support from NIH and the American Recovery and Reinvestment Act (ARRA), Lentine and her team are highlighting geographical disparities and working to develop improved systems to ensure fairness in organ allocation.
Lentine’s motivation stems from her observation that patients with similar illness severity experience different waiting times due to imbalances in geographical supply and demand. For example, the average waiting time for a blood group O kidney varies from 2.8 years in a well-supplied Midwest region to more than 6 years in a West Coast region.
Krista Lentine, M.D., associate professor of medicine at Saint Louis University
The United States currently is divided into 11 geographic organ-sharing regions that direct organ distribution. Operating within this geographical system are nationally agreed-upon rules that define priority among transplant candidates. For liver transplants, priority is determined based on illness severity using a scoring system that predicts the patient’s risk of death without a transplant. For those awaiting kidney transplants, however, priority is mostly determined by how long the patients have been waiting.
“These regions were not developed by any scientific method, but the intent was to divide the country in a way that would place organs quickly and encourage local donation,” said Lentine. “However, the current regions are heterogeneous in size and population, leading to mismatching in available organs with waiting candidates.”
Lentine and her team are using methods based on mathematical programming models to design new regional boundaries that would balance organ demand with donation rates across the country. Specifically, the goal of the project is to reduce disparities across geography in illness severity at the time of transplant for liver transplant patients and to equalize waiting time for kidney transplant patients.
To most effectively accomplish these goals, Lentine is collaborating with investigators at different institutions to tap into expertise in statistics, modeling, and health care economics, which are all necessary to achieve the objectives of her project.
ARRA funding enabled multi-institutional collaboration, and funds were used to support necessary investigators, including biostatisticians, who would not have otherwise been able to conduct the work. ARRA funds were also critical in purchasing data from the Centers for Medicare and Medicaid Services to use in economic evaluation.
Compounding Disparities
Although Lentine’s main focus is geographic disparities, she also has found disparities across socio-demographically defined subgroups in transplant access. Using this information, Lentine is investigating the impact of her team’s redistribution design for at-risk populations, including racial minorities and patients of low socioeconomic status. These disparities are often interrelated with geographic barriers. For example, kidney transplant candidates may be able to reduce their wait time if they are able to relocate to a better supplied area, but this option may only be feasible for wealthy, well-insured patients.
As part of the ARRA grant, Lentine and her team combined transplant registry and U.S. census data for kidney transplant candidates to assess the impact of socioeconomic status, distance from residence to the transplant center, and relocation to a different donation service area. Their 2010 study showed that patients could get improved access to kidney transplantation by traveling to more well-supplied regions, but that option is more available to those with greater income and with private insurance.
“We believe that more equitable sharing of organs has the potential to decrease regional disparities in waiting times. We are also working on a similar analysis among liver transplant candidates as a part of this grant.” —Dr. Krista Lentine
Looking Ahead
Lentine and her colleagues have been sharing their results through presentations and published papers during 2010 and 2011. The project has a complex agenda, and although important foundational work has been accomplished with ARRA funds, there is more to be done in order to analyze and improve organ distribution and access.
“The ARRA award provided vital initial funding, and we will work to find support to continue this important effort,” Lentine said.
Going forward, Lentine plans to conduct a full cost-benefit analysis of the final proposed redesign of the liver redistribution system and continue work on the optimization of kidney distribution.
With continued work and improved geographical distribution models, more people like Reginald may spend less time on a transplant waiting list and more time enjoying life with the organs they need.
