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Award Detail

Awardee:NORTHWESTERN UNIVERSITY
Doing Business As Name:Northwestern University
PD/PI:
  • Sanjay Mehrotra
  • (847) 491-3155
  • mehrotra@northwestern.edu
Co-PD(s)/co-PI(s):
  • John J Friedewald
  • Daniela P Ladner
Award Date:08/13/2011
Estimated Total Award Amount: $ 315,000
Funds Obligated to Date: $ 319,800
  • FY 2013=$4,800
  • FY 2011=$315,000
Start Date:09/01/2011
End Date:08/31/2016
Transaction Type:Grant
Agency:NSF
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.041
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Addressing Geographical Disparities in Transplant Organ Accessibility Across United States
Federal Award ID Number:1131568
DUNS ID:160079455
Parent DUNS ID:005436803
Program:SERVICE ENTERPRISE SYSTEMS
Program Officer:
  • Georgia-Ann Klutke
  • (703) 292-2443
  • gaklutke@nsf.gov

Awardee Location

Street:750 N. Lake Shore Drive
City:Chicago
State:IL
ZIP:60611-4579
County:Chicago
Country:US
Awardee Cong. District:07

Primary Place of Performance

Organization Name:Northwestern University
Street:2145 Sheridan Road
City:Evanston
State:IL
ZIP:60208-3119
Country:US

Abstract at Time of Award

The objective of this research is to develop advanced mathematical models with sufficient granularity to guide the United Network of Organ Sharing decision makers in crafting an implementable policy towards reducing the geographic disparity of Kidney allocation over time. Nearly 700,000 patients currently receive kidney replacement therapy either in the form of hemodialysis or kidney transplantation, consuming $24 billion (6.4 percent) in Medicare expenditures annually. Kidney transplantation, where a patient receives a healthy kidney from either a deceased or living donor, has a significantly better five-year patient survival of 81.2 percent, an improved quality of life, and leads to significant cost-savings. However, kidney transplantation is marred by the shortage of available kidney organs. The US Department of Health and Human Services in their "Final Rule" states, "Organs and tissues ought to be distributed on the basis of objective priority criteria, and not on the basis of accidents of geography." The current national kidney allocation system is plagued by geographic disparities in the waiting time associated with kidney transplantation. The median waiting time during 2000-2009 varies from 0.93 years to 4.14 years depending on a patient's local area of listing. The model will incorporate simulation based input and output in an optimization framework that consistently considers multiple equity objectives within a planning-type framework. Such modeling is necessary to incorporate detailed patient population characteristics, transplant center behavior, the quality of available organs, acceptability of the model generated solution by key stakeholders, and the ease of implementing the suggested policy. The solution techniques and algorithms developed for this research would be potentially applicable to other distribution problems where equity needs to be achieved. The project will involve and train graduate students and research outcomes will be used to inform the transplant community through presentations at national conferences.

Publications Produced as a Result of this Research

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Davis AE, Mehrotra S, Kilambi V, Kang J, McElroy L, Lapin B, Holl J, Abecassis M, Friedewald JJ, Ladner DP "The effect of the Statewide Sharing variance on geographic disparity in kidney transplantation in the United States." Clin J Am Soc Nephrol, v.9, 2014, p.1449-60. doi:10.2215/CJN.05350513 

Ashley E Davis, Sanjay Mehrotra, Daniela P Ladner, Vikram Kilambi, and John J Friedewald "Changes in Geographic Disparity in Kidney Transplantation since the Final Rule" Transplantation, v.98, 2014, p.931-36. doi:10.1097/TP.0000000000000446 

Ashley Davis, Sanjay Mehrotra, John Friedewald, Mark Daskin, Anton Skaro, Michael Abecassis, Daniela Ladner "Improving Geographic Equity in Kidney Transplantation Using Alternative Kidney Sharing and Optimization Modeling" Journal of Medical Decision Making, v.35, 2015, p.979. doi:PMID: 25385750 

Sanjay Mehrotra, Vikram Kilambi, Richard Gilroy, Daniela P Ladner, Goran B Klintmalm, and Bruce Kaplan "Modeling the Allocation System: Principles for Robust Design before Restructuring" Transplantation, v.99, 2015, p.278. doi:10.1097/TP.0000000000000656 

Daniela P. Ladner and Sanjay Mehrotra "Methodological Challenges in Solving Geographic Disparity in Liver Allocation" JAMA Surgery, v., 2015, p.. doi:10.1001/jamasurg.2015.3937 

Ashley Davis, Sanjay Mehrotra, Daniela P Ladner, John J Friedewald, Anton Skaro, Jane Holl and Michael Abecassis "Improving Geographic Equity in Kidney Transplantation Using Alternative Sharing and Optimization Modeling" Medical Decision Making, v.35, 2015, p.979. doi:10.1177/0272989X14557696 

Ashley E Davis, Sanjay Mehrotra, Daniela P Ladner, Vikram Kilambi, and John J Friedewald "Changes in Geographic Disparity in Kidney Transplantation since the Final Rule" Transplantation, v.98, 2014, p.931. doi:10.1097/TP.0000000000000446 

Ashely E. Davis, Sanjay Mehrotra, Lisa McElroy, John J. Friedewald, Anton I. Skaro, Brittany Lapin, Raymond Kang, Jane Holl, Michael M. Abecassis, and Daniela P. Ladner "The Extent and Predictors of Geographic Disparity in Kidney Transplantation in the United States" Transplantation, v.97, 2013, p.1049-57. doi:10.1097/01.tp.0000438623.89310.dc 

Ashley E Davis, Sanjay Mehrotra, Vikram Kilambi, Joseph Kang, Lisa McElroy, Brittany Lapin, Jane Holl, Michael Abecassis, John J Friedewald, Daniela P Ladner "The Effect of the Statewide Sharing Variance on Geographic Disparity in Kidney Transplantation in the US" Clinical Journal of American Society of Nephrology, v.9, 2014, p.931. doi:10.2215/CJN.05350513 

Ashley Davis, Sanjay Mehrotra, John Friedewald, and Daniela Ladner "CHARACTERISTICS OF A SIMULATION MODEL OF THE NATIONAL KIDNEY TRANSPLANTATION SYSTEM" Proceedings of the Winter Simulation Conference, v., 2013, p.. doi:978-1-4799-3950-3 

Sanjay Mehrotra, Vikram Kilambi, Richard Gilroy, Daniela P Ladner, Goran B Klintmalm, and Bruce Kaplan "Modeling the Allocation System: Principles for Robust Design before Restructuring" Transplantation, v.99, 2015, p.279. doi:10.1097/TP.0000000000000656. 

Davis AE, Mehrotra S, McElroy LM, Friedewald JJ, Skaro A, Lapin B, Kang R, Holl JL, Abecassis MM, Ladner DP. "The extent and predictors of waiting time geographic disparity in kidney transplantation in the United States" Transplantation, v.97, 2014, p.1049-57. doi:10.1097/01.tp.0000438623.89310.dc 


Project Outcomes Report

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The current national organ allocation system is plagued by geographic disparities in the waiting time associated with transplantation.  For example, the median waiting time for kidney transplant during 2000-2009 varied from 0.93 years to 4.14 years depending on a patient’s local area of listing. A similar disparity exists in liver transplant. The major goal of the proposed research was to study the properties of the current kidney and liver allocation systems, and develop advanced mathematical models with sufficient granularity to guide the United Network of Organ Sharing (UNOS) decision makers in crafting an implementable policy towards reducing the geographic disparity. 

Outcomes:

Societal Impact:
Results show that more than 500 lives can be saved yearly through an improved allocation system. National policy makers in liver transplantation were informed through several invited presentation to United Network of Organ Sharing (UNOS) liver and intestine committee. Presentations were also made at the national liver forum. The neighborhoods framework for organ allocation developed in this research is being discussed as an alternative to the redistricting solution in liver allocation. This research also resulted in several invited keynote presentations at national conferences in the areas of Operations Research and Management Sciences, as well as invited workshops and panels in the areas of transplantation. The UNOS leadership has been engaged in these presentations.

Scientific Outcomes:
Our analysis showed that on important metrics geographic disparity has continued to worsen since the final rule. We found that in DSAs with longer waiting times, there were significantly more patients suffering from end-stage renal disease and more patients listed for kidney transplant, lower kidney procurement rates, and higher transplant center competition. Patients were more likely black, sensitized, with lower educational attainment and less likely to waitlist outside of their DSA of residence. Donor organs used in DSAs with long waiting times were more likely hepatitis C positive and had a higher kidney donor profile index. Graft and patient survival at 5 years was worse for deceased donor kidney transplant, but rates for living donor kidney transplant were higher. Our analysis also showed that a statewide sharing variance to the national kidney allocation policy given to Tennessee and Florida resulted in significant reduction in geographic disparity in these states in deceased-donor kidney transplant rates, waiting time to transplantation, cumulative dialysis time at transplantation, 5-year graft survival, and cold ischemia time. We found that it would be possible to significantly alleviate geographic disparity by making limited changes to the current system, as compared to a sweeping nationwide change. Such changes can be made in the context of statewide sharing and creating regional sharing partners.

In the context of liver allocation we introduced a new notion of an OPO's neighborhood - a collection of DSAs surrounding the OPO that act as the OPO's region in the current local-regional-national framework. The concept of neighborhoods incorporates previously studied concepts of districts and concentric circles as special cases. We developed a stochastic optimization model following Rawls principle of justice. Compared to the current allocation, simulation results showed that neighborhoods reduce the DSA-average MELD standard deviation by 29% and save about 65 lives annually. Compared to a redistricting solution that is part of a current national debate, the neighborhoods had a smaller average transport distances that were more uniform across DSAs, saved more lives, and achieved greater reduction in disparity. The neighborhood framework allows the possibility of generating a set of solutions that provide alternatives which can be used to trade-off reduction in disparity with cost and lives saved.

Training and Human Resource Development:
Two PhD students were trained. These student were intimately involved with research and its documentation and presentation for the entire duration. They also developed simulation software for organ allocation systems based on the proposed research. Nine research papers were published or accepted for publication based on the research results. The PI was invited to make a presentation in 2015 at the National Liver Forum on organ allocation to inform changes in national live allocation policy. He was also invited to make several presentations to the United Network of Organ Sharing (UNOS) liver and intestine committee. He was also invited to organize a symposium at 2014 "Advancing Science and Serving Society" summit.  The participants in the symposium included the 2012 Nobel Laureate, and leading ethics and policy professionals working in the area of transplantation.  The symposium followed by a news media coverage.  He was also invited to give presentations on this topic at several academic institutions and conferences. The research outcomes were also included in a plenary talk given by the PI at Institute for Operations Research and Management Science (INFORMS) 2015 national meeting, and at Euro-INFORMS 2013 meeting. PI was moderate a panel at the 2016 American Society of Transplant Surgeon meeting and a panel at 2016 Institute for Operations Research and Management Science meeting.

 


Last Modified: 12/20/2016
Modified by: Sanjay Mehrotra

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