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Tuesday, March 7, 2017

Global Kidney Exchange

Imagine that I need a kidney donation, and I've got a willing donor. But there's a problem: their donated kidney will not be physically compatible with me. What can be done? For Al Roth, the natural next thought is whether it's possible to find a two pairs of people who could carry out an exchange, in which my willing donor gives a kidney to you, and your willing donor gives a kidney to me. And next, you can think of multiple pairs of people, where each person who needs a kidney also brings along a willing kidney donor, and we figure out a chain of swaps where each of those who need a kidney can get one from a compatible donor.

As part of a series called "From Research to Reward," the National Academy of Sciences has produced a nice 5-minute video of this kind of kidney exchange called "The Matchmaker: An Economist Tackles Kidney Exchange." It features a couple where the husband needed a kidney and his wife was a willing donor, but her kidney was not compatible for him, so she donated to someone else and he received a donated kidney from someone else. The wife says: "This algorithm that was created by this economist, I cannot explain enough how it gives you back your life."

Now comes the idea of "global kidney exchange," put forward in "Kidney Exchange to Overcome Financial Barriers to Kidney Transplantation," American Journal of Transplantation (March 2017, pp. 782-790) by a team of authors: Michael A. Rees, Ty B. Dunn, Christian S. Kuhr, Christopher L. Marsh, Jeffrey Rogers, Susan E. Rees, Alejandra Cicero, Laurie J. Reece, Alvin E. Roth, Obi Ekwenna, David E. Fumo, Kimberly D. Krawiec, Jonathan E. Kopke, Samay Jain, Miguel Tan and Siegfredo R. Paloyo.

Basically, the notion is to involve pairs of people from low-income countries--one needing a kidney, one offering to donate a kidney--in these interlocking chains of kidney donation. For those in high-income countries, the advantage is potentially a lot more compatible kidney donors. Because getting a kidney donation saves money on dialysis, it is possible to use that saved money and provide the kidney donation for free to recipients from the low-income country. The result is healthier people, and overall cost savings. The authors explain the idea this way (footnotes omitted):

Recent worldwide estimates suggest that 2–7 million people died prematurely in 2010 because they did not have access to renal replacement therapy (RRT). In countries that provide universal citizen access to end-stage renal disease (ESRD) treatment, the cost of hemodialysis is generally more than twice the cost of renal transplantation when time horizons of >1 year are considered. This disparity provides an opportunity for payers in developed countries to pay for two kidney transplantations and still reduce their overall cost compared with keeping one of their patients on hemodialysis. ...
Organ shortage is the major limitation to kidney transplantation in the developed world. Conversely, millions of patients in the developing world with endstage renal disease die because they cannot afford renal replacement therapy—even when willing living kidney donors exist. This juxtaposition between countries with funds but no available kidneys and those with available kidneys but no funds prompts us to propose an exchange program using each nation’s unique assets. Our proposal leverages the cost savings  achieved through earlier transplantation over dialysis to fund the cost of kidney exchange between  developed-world patient–donor pairs with immunological barriers and developing-world patient–donor pairs with financial barriers. By making developed-world health care available to impoverished patients in the developing world, we replace unethical transplant tourism with global kidney exchange—a modality equally benefitting rich and poor. We report the 1-year experience of an initial Filipino pair, whose recipient was transplanted in the United States with  an American donor’s kidney at no cost to him. The Filipino donor donated to an American in the United States through a kidney exchange chain. Follow-up care and medications in the Philippines were supported by funds from the United States.
In this particular case, what seems to have happened is that the foreign donor unlocked a chain of possible other kidney donations and recipients.  The authors write:
The first GKE [global kidney exchange] was performed as a NEAD [nonsimultaneous extended altruistic donor] chain that has subsequently provided transplantations for one Filipino and 10 American ESRD patients. Six recipients had Medicare as their primary health insurance payer, and four  had commercial payers. If each of the ten health insurance payers had prospectively agreed to pay their share  of the approximately $160 000 that was provided by APD [Alliance for Paired Donation] to cover the cost of the Filipino donor and recipient’s  expenses, each payer would have paid approximately $16 000. Assuming that over the next 5 years the average savings per patient transplanted is $300 000, the reported GKE reduced the cumulative cost of health care for these payers by approximately $3 million. Critical to the scalability of GKE is recognition that if the average cost reduction is only $160 000 over 5 years (a conservative estimate), the concept is financially neutral even if performed as a simple two-way exchange.
The same issue of the journal includes a short editorial called "Financial Incompatibility and Paired Kidney Exchange: Walking a Tightrope or Blazing a Trail?" by A. C. Wiseman and J. S. Gill (pp. 597-98).  As they write, "there are numerous considerations that require equipoise ..." They point out issues that could arise in how donors in other countries are identified, whether the benefits are equitably distributed, whether consent is freely given, how this might affect providers of transplant services in low-income countries, and more. All fair enough, and I suppose only a benighted economist could bristle against their request for "sensitivity to the ethical pitfalls." I would only point out that while we are being sensitive to ethical pitfalls of global kidney exchange, 2-7 million people are dying every year without access to treatment for their kidney disease, and we should spare a little sensitivity for them, too.