Showing posts sorted by date for query priority AND Israel. Sort by relevance Show all posts
Showing posts sorted by date for query priority AND Israel. Sort by relevance Show all posts

Saturday, July 27, 2024

An Experimental Study of the Chinese Organ Allocation System

 China presently has a low rate of organ donations per million population, so there's a lot of room for growth.  Here's a study suggesting that giving priority on the waiting list to family members of donors could help (as it has done in Israel):

Li, Danyang, Luo, Jun, Ye, Hang and Zheng, Heng. "Is Family-Priority Rule the Right Path? An Experimental Study of the Chinese Organ Allocation System" The B.E. Journal of Economic Analysis & Policy, vol. 24, no. 3, 2024, pp. 929-964. https://doi-org.stanford.idm.oclc.org/10.1515/bejeap-2023-0213

Abstract: China is experiencing an organ shortage crisis. We experimentally test the effectiveness of the family-priority allocation rule on organ donation and argue that such incentive would be highly motivating in Chinese family-oriented culture. Results of our experiment show that introducing the family-priority rule can not only increase donor registration but also promote family consent. Such priority rule would be particularly effective to increase deceased organ donation in China, as it will significantly promote donor registration and meanwhile generate a consistent higher family consent rate in a more family-orientated culture.

Tuesday, March 19, 2024

The Impact of prioritization on kidney and liver allocation in Israel

   Israel's  Organ Transplantation Law grants some priority on waiting lists for transplants to candidates who are first-degree relatives of deceased organ donors (i.e. whose family has given permission for someone's deceased organ donation) or who previously registered as organ donors themselves. (There's also a tiny priority for relatives of people who signed organ donor cards...)  Here are two papers that looks at the effect of those priorities on kidney and liver transplants, and how they interact with other priorities on waiting lists for Israeli organs.  

The first paper, on kidneys, concludes that the priorities are effective in reducing waiting time to transplant, and suggests that perhaps these priorities should not be so large compared to other existing priorities (e.g. for time on dialysis), or for priorities that could be established, e.g. for highly sensitized patients (who get high priority in the U.S., for example.)

Mor, Eytan, Meitar Bloom, Ronen Ghinea, Roi Anteby, Ronit Pasvolsky-Gutman, Ron Loewenthal, Ido Nachmani, and Tammy Hod. "The Impact of the Donor Card Holder Prioritization Program on Kidney Allocation in Israel." Transplantation (2024): 10-1097.

Abstract

Background: Since 2014, as part of a priority program within the Israeli Transplant Law, additional points were given to waitlisted candidates with donor cards. We assessed the impact on deceased donor kidney allocation.

Methods: This study enrolled all patients older than 18 y who underwent deceased donor kidney transplantation (January 2016–December 2019). Data were obtained from the National HLA Tissue Laboratory registry at the Sheba Medical Center. Patients were grouped by donor card status (ADI group) (not signed, 0 points; relative signed, 0.1 points; patient signed, 2 points; and relative donated, 9 points). The primary outcome was waiting time until kidney transplantation with and without the additional score.

Results: Four hundred forty-four patients underwent kidney transplantation during the study period: 281 (63%) were donor card holders (DCH) and 163 (37%) were not DCH. DCH with extra points waited 68.0 (±47.0) mo on average, compared with 94.6 (±47.3) mo for not DCH (P < 0.001). Donor card signers had a shorter time until transplant in a multivariable model. Without extra points, 145 recipients (32.6%) would have missed organs allocated to higher-scored candidates. Allocation changes occurred in 1 patient because of an additional 0.1 points, in 103 candidates because of an additional 2 points, and in 41 candidates because of an additional 9 points.

Conclusions: Additional DCH scores improved allocation and reduced waiting time for donor card signers and those with donating relatives. To enhance fairness, consideration should be given to reducing the score weight of this social criterion and raising scores for other factors, especially dialysis duration.

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There are many fewer liver transplants than kidney transplants, and the effect of priority is less clear:

Ashkenazi, Tamar, Avraham Stoler, and Eytan Mor. "The effect of priority given to donor card holders on the allocation of livers for transplant—evidence from 7 years of the Israeli priority program." Transplantation 106, no. 2 (2022): 299-307.

Abstract

Background. The Israeli Transplant Law grants priority in organ allocation to patients signing a donor card. Liver transplant candidates get additional 2 points on their Model for End Stage Liver Disease score for signing a donor card, 0.1 points for a relative holding a card, and 5 points if a relative donated an organ. We studied the effect of the priority program on waiting list mortality and allocation changes due to priority.

Methods. Using Israeli Transplant data of 531 adult liver transplant candidates with chronic liver disease listed between 2012 and 2018 we compared waitlist mortality and transplant rate of candidates with and without priority. Then we analyzed liver allocations resulting from additional priority points and followed outcome of patients who were skipped in line.

Results. Of the 519 candidates, 294 did not sign a donor card, 82 signed, 140 had a relative sign, and for 3, a relative donated an organ. The rates of waitlist mortality in these 4 groups were 22.4%, 0%, 21.4%, and 0%, respectively, and the transplant rates were 50%, 59.8%, 49.3%, and 100%, respectively. Of the 30 patients who were skipped because of priority, 24 subsequently underwent transplant, 2 are on the waiting list, and 4 died within 0.75, 1.75, 7, and 17 mo.

Conclusions. The 2 points added to the Model for End Stage Liver Disease score were associated with lower waitlist mortality and higher transplant rate for candidates signing a donor card without significantly affecting access to transplant during allocation. Further research and consideration of optimal policy when granting priority for candidates signing a donor card should continue.

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Earlier:

Stoler, Avraham,  Judd B. Kessler, Tamar Ashkenazi, Alvin E. Roth, Jacob Lavee, “Incentivizing Authorization for Deceased Organ Donation with Organ Allocation Priority: the First Five Years,” American Journal of Transplantation, Volume 16, Issue 9, September 2016,  2639–2645.

 Stoler, Avraham, Judd B. Kessler, Tamar Ashkenazi, Alvin E. Roth, Jacob Lavee, “Incentivizing Organ Donor Registrations with Organ Allocation Priority,”, Health Economics, April 2016 Volume: 26   Issue: 4   Pages: 500-510   APR 2017


Monday, January 23, 2023

Incentives for deceased organ donation, in Asia

 Here's a discussion, in an Asian context, of providing incentives to families to consent to deceased donation.

Introducing Incentives and Reducing Disincentives in Enhancing Deceased Organ Donation and Transplantation by Kai Ming ChowMBChB⁎ Curie AhnMD† Ian DittmerMBChB‡ Derrick Kit-SingAuLMCHK§ IanCheungMBBS║ Yuk LunChengMBChB¶ Chak SingLau MBChB Deacons Tai-KongYeungMBBS║ Philip Kam-TaoLi MD Seminars in Nephrology,  Available online 27 December 2022

*Department of Medicine and Therapeutics, Carol and Richard Yu PD Research Centre, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong

† Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, South Korea

‡Department of Renal Medicine, Auckland City Hospital, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand

§Centre for Bioethics, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong

║Cluster Services Division, Hospital Authority, Kowloon, Hong Kong

¶Department of Medicine, Alice Ho Miu Ling Nethersole Hospital, Tai Po, Hong Kong

#Department of Medicine, Queen Mary Hospital, University of Hong Kong, Pok Fu Lam, Hong Kong, China

Summary: Despite the effectiveness of solid organ transplantation, progress to close the gap between donor organs and demand remains slow. An organ shortage increases the waiting time for transplant and involves significant costs including patient morbidity and mortality. Against the background of a low deceased organ donation rate, this article discusses the option of introducing incentives and removing disincentives to deceased organ donation. Perspectives from ethics, general public opinion, and the health care profession are examined to ensure a comprehensive appraisal and illustrate different facets of opinion on this complex area. Special cultural and psychosocial considerations in Asia, including the family based consent model, are discussed.


This sentence caught my eye:

"After suggestion by Economics Nobel Laureate Alvin Roth for the community to unite to remove disincentives to kidney donation, the transplant community and academia have been having more discussion and analysis. That, in part, hinges on the estimates of the economic welfare gain for the society as a whole."

...

"PERSPECTIVES OF ASIAN SOCIETY

"It is widely recognized that deceased organ donation rates in Asian countries have been significantly lower than that in Western countries.

...

"No one disputes the social and cultural beliefs in the decision to donate organs. 

...

"An example of honoring the principles of reciprocity in incentivizing organ donor registrations is the organ allocation priority policy. Israel became the first country in 2008 to enact legislation incorporating such incentives based on individuals’ willingness to donate into their organ procurement system.26,42,43 The policy provides an incentive or motivation by the reciprocal altruistic dictum that “each partner helping the other while he helps himself,”42 granting priority on organ donor waiting lists to those individuals who registered as organ donors by signing a donor card for at least 3 years. Subsequent observations in Israel, as analyzed 5 years after introduction of the new policy, included an increase in the authorization rate of next of kin of unregistered donors, as well as a two-fold higher likelihood of next-of-kin authorization for donation when the deceased relative was a registered donor.44

"How does the concept of reciprocity apply for Asian societies? Will the results from Israel be replicated in Asia? Although social exchange theory should be a universal normal applicable to all human relationships, cultural influence or patterns might differ. Previous research on reciprocity across different cultural contexts, indeed, has shown that East Asians tend to reciprocate in kind and emphasize more on equity-based theory than Americans.45 Viewed through such a lens of “to give is to take,” it is relevant to quote another similar example in Taiwan, where incentives were provided to deceased organ donors’ families. In brief, after a person has become a deceased organ donor in Taiwan, up to three of his or her blood relatives will be granted priority to receive a deceased donor organ should they be on the waiting list for transplantation.46

"At the heart of the issue is the family based consent that is unique and vital, albeit not exclusive, in Confucian tradition within Chinese societies. It is important to note that organ donation is more often a family based consent process in Chinese culture than those “from a Western cultures”. As such, family priority right provided in the Israel or Chinese model would be more likely to motivate organ donation within a family based ethical culture.47 As in any discussion of culture's influence on organ donation decision, we must be mindful that East Asians tend to favor family centered decision making.

...

"If the concept of reimbursing funeral expenses for deceased organ donors is explored further then these four tenets are suggested as a guide: Tenet 1: the overarching principle is to appreciate and recognize the altruistic behavior of organ donors, and not the next of kin. Tenet 2: the second priority of reimbursing funeral expenses is to motivate the passive-positive public to sign up for organ donation. Tenet 3: the ultimate beneficiary from an incentive system is society, with an improved deceased organ donation rate. Government and charitable organizations, but not organ recipients, should be the source of payment. Tenet 4: as a token of expressing gratitude to the deceased organ donors, funeral expenses reimbursement preferably should be offered to those who have expressed the wish to donate (donor registration); they should have been provided the option to decline the offer."

Monday, October 4, 2021

More on the UAE-Israel kidney exchange

If you're just tuning in, you can follow the story of the kidney exchange between the UAE and Israel here. The pairs who exchanged kidneys were an Israeli Arab husband and wife, a Jewish Israeli mother and daughter, and a mother and daughter who wish to be identified only as Arab residents of the United Arab Emirates.  (I joined their family at their home for a meal when I was in Abu Dhabi, but won't say more about them.)

It isn't a surprise that the donor in each pair couldn't donate to the intended recipient, because in each pair the recipient was a highly sensitized mother ( i.e. for whom it was hard to find a compatible kidney, because she had many antibodies against human proteins). During childbirth, mothers can develop such antibodies to the father's proteins that the children inherited. So the father and the daughters were incompatible donors, since the mother had antibodies against the paternal proteins (human leukocyte antigens) in their kidneys. Together with the fact that the mothers were quite hard to match, and that Israel and the UAE are both small, each with populations of around ten million, they had to look across national borders.

Cross border kidney exchange requires some diplomacy, particularly when the countries involved are getting together for the first time (and don't necessarily have a long history of cooperation). The key medical diplomats were Dr. Tamar Ashkenazi* the director of Israel Transplant and Dr Ali Abdulkareem Al Obaidli, Chairman of the UAE National Transplant Committee.  (Other key collaborators in the complicated logistics were Itai Ashlagi at Stanford and Atul Agnihotri and Mike Rees of the Alliance for Paired Kidney Donation.)  


So this was the plan:


And here's a picture of the Abu Dhabi kidney packed for shipping (masked in the picture are Sue and Mike Rees, who have a lot of experience with packing and shipping kidneys, another nurse whose name I don't know, and Dr. Muhammad Badar Zaman the UAE transplant surgeon who transplanted the  kidney that was on the way.


The little box taped to the top of the shipping container allows the kidney to be tracked in transit, via an app that gives you a picture of where it is at it travels:


And here's the swap of the two kidneys in shipping containers in the airport in Abu Dhabi (Tamar Ashkenazi and Dr. Ali are in the center, Atul and Mike are at the two ends...). Dr Ashkenazi was on both legs of the flight above--she flew in with the Israeli kidney and flew out with the UAE kidney.



On my last night in Abu Dhabi I had dinner with a lot of the docs. Across from me in the picture below are the two surgeons most actively involved in this exchange on the UAE side, transplant surgeon Dr. Zaman and the nephrectomy surgeon Dr. Hamid Reza Toussi.  Next to me is the nephrologist Dr. Mohamed Yahya Seiari.





Below is that whole dinner party. If you've been following these posts up til now, you've met all of them except the gentleman second from the left, Dr. Gehad ElGhazali, who is the head of the HLA lab, which is responsible for the data that allows the matching algorithm to predict which kidneys are compatible, and is responsible for the final 'crossmatch' tests that verify compatibility. Like all the other docs I encountered, he has a multi-international background. This reflects the UAE's very international population, which is why it seems a natural global hub for kidney exchange.




I only met the Israel participants in the exchange later, by Zoom: Shani Markowitz is the donor from the Jewish pair, and Walaa Azaiza is the recipient from the Israeli Arab pair.






The Israeli transplant surgeons are Dr Tony Karam at Rambam Hospital and Dr. Eitan Mor at Sheba Medical Center.
^^^^^^^^^^^^^^^^^^^

*As it happens, I've twice had the privilege of  being Dr. Ashkenazi's coauthor (concerning deceased organ donation):
1. Stoler, Avraham,  Judd B. Kessler, Tamar Ashkenazi, Alvin E. Roth, Jacob Lavee, “Incentivizing Authorization for Deceased Organ Donation with Organ Allocation Priority: the First Five Years,” American Journal of Transplantation, Volume 16, Issue 9, September 2016,  2639–2645. http://onlinelibrary.wiley.com/doi/10.1111/ajt.13802/full 

2. Stoler, Avraham, Judd B. Kessler, Tamar Ashkenazi, Alvin E. Roth, Jacob Lavee, “Incentivizing Organ Donor Registrations with Organ Allocation Priority,”, Health Economics, April 2016 online http://onlinelibrary.wiley.com/doi/10.1002/hec.3328/full ; doi: 10.1002/hec.3328. In print: Volume: 26   Issue: 4   Pages: 500-510   APR 2017



Thursday, January 7, 2021

Vouchers for organ donation, by Kim, Li, and Xu in JET

There are now a number of ways in which an organ donation (or registration as an organ donor) can turn into a future priority for receiving an organ.  Here's a paper from the January JET that looks at an overlapping generation model in which priority vouchers can be inherited by family members. The paper considers how, while this increases the incentive for the patriarch (or matriarch) of a family to register as a deceased donor, inheriting the voucher might reduce the incentive for descendants to donate, since they already have some priority on the deceased donor waiting list.  The paper models how this can be avoided by giving inherited vouchers increased priority when the current recipient registers.


Organ donation with vouchers by Jaehong Kim, Mengling Li, and Menghan Xu,  Journal of Economic Theory, Volume 191, January 2021, https://doi.org/10.1016/j.jet.2020.105159 

Abstract: The ever-increasing shortage of organs for transplantation has motivated many innovative policies to promote the supply of organs. This paper proposes and analyzes a general class of deceased organ allocation policies that assign priority on organ waiting lists to voucher holders to promote deceased donor registration. Priority vouchers can be obtained by self-registering for donation or through family inheritance. In an overlapping generations framework, we find that extending the donor priority benefits to future generations can improve the aggregate donation rate and social welfare. In particular, giving higher priority to voucher inheritors who register for donation is always beneficial regardless of the levels of population growth and care for future generations. By contrast, the efficacy of granting priority to nondonors with inherited vouchers depends on these two sociodemographic factors because of potential free-riding incentives.

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Related post:

Monday, September 26, 2016

Thursday, April 20, 2017

Match Up 2017: April 20-21 at Microsoft Research New England

MATCH-UP 2017, the fourth workshop in the series of interdisciplinary and international workshops on matching under preferences, will take place April 20-21, 2017.
Venue:Microsoft Research New England Cambridge, MA 02142

DAY 1

8:00 A.M.Breakfast
8.45 A.M.Invited Talk 1 —Estelle Cantillon, Université libre de Bruxelles

The efficiency – stability tradeoff in school choice: Lessons for market design

Abstract: A well-known result for the school choice problem is that ex-post efficiency and stability may not be compatible. In the field, that trade-off is sometimes small, sometimes big.  This talk will summarize existing and new results on the drivers of this trade-off and derive the implications for the design of priorities and tie-breaking rules.
9.30 A.M.Session 1
10.30 A.M.Break
10.50 A.M.Session 2
12.30 P.M.Lunch
1:00 P.M.Outlook Talk 1 – Al Roth, Stanford

Frontiers of Kidney Exchange

Abstract: Kidney exchange is different from many market design efforts I’ve been involved in, because it affects the everyday conduct of transplant centers, so we’re constantly adapting to their big strategy sets…(in contrast to e.g. annual labor markets or school choice which don’t affect the daily conduct of residency programs and schools …)The early design challenges in kidney exchange mostly involved dealing with congestion (and the solutions involved long chains, standard acquisition charges, and attempts to better elicit surgeons’ preferences over kidneys).The current challenges to kidney exchange involve creating more thickness in the markets, and I’ll touch on several new initiatives:




  • 1. Frequent flier programs to encourage transplant centers to enroll more of their easy to match pairs;
  • 2. Global kidney exchange;
  • 3. Information deserts: populations of Americans who don’t get transplants;
  • 4. Deceased donor initiated chains ;

  • a. Increasing deceased donation: military share, priority in Israel
    2:00 P.M.Session 3
    3.40 P.M.Break
    4:00 P.M.Session 4
    5:00 P.M.Invited Talk 2 – Aaron Roth, UPENN

    Approximately Stable, School Optimal, and Student-Truthful Many-to-One Matchings (via Differential Privacy)

    Abstract: In this talk, we will walk through a case study of how techniques developed to design “stable” algorithms can be brought to bear to design asymptotically dominant strategy truthful mechanisms in large markets, without the need to make any assumptions about the structure of individual preferences. Specifically, we will consider the many-to-one matching problem, and see a mechanism for computing school optimal stable matchings, that makes truthful reporting an approximately dominant strategy for the student side of the market. The approximation parameter becomes perfect at a polynomial rate as the number of students grows large, and the analysis holds even for worst-case preferences for both students and schools.
    Joint work with: Sampath Kannan, Jamie Morgenstern, and Zhiwei Steven Wu.
    5.45 P.M.Break
    6:00 P.M.Poster Lightning Talks
    6.30 P.M.Reception and Poster Session
    8:00 P.M.END

    DAY 2

    8:00 A.M.Breakfast
    8.45 A.M.Invited Talk 3 — Michael Ostrovsky, Stanford

    Matching under preferences: beyond the two-sided case

    Abstract: I will present an overview of several recent papers showing that most of the key results of matching theory generalize naturally to a much richer setting: trading networks. These networks do not need to be two-sided, and agents do not have to be grouped into classes (“firms”, “workers”, and so on). What is essential for the generalization is that the bilateral contracts representing relationships in the network have a direction (e.g., one agent is the seller and the other is the buyer), and that agents’ preferences satisfy a suitably adapted substitutability notion. For this setting, for the cases of discrete and continuous sets of possible contracts, I will discuss the existence of stable outcomes, the lattice structure of the sets of stable outcomes, the relationship between various solution concepts (stability, core, competitive equilibrium, etc.), and other results familiar from the literature on two-sided markets.
    9.30 A.M.Session 5
    10.30 A.M.Break
    10.50 A.M.Session 6
    12.30 P.M.Lunch
    1:00 P.M.Lunch w/Outlook Talk 2 — David Manlove, University of Glasgow

    Selected Algorithmic Open Problems in Matching Under Preferences

    Abstract: The research community working on matching problems involving preferences has grown in recent years, but even so, plenty of interesting open problems still exist, many with large-scale practical applications.  In this talk I will outline some of these open problems that are of an algorithmic flavour, thus giving an outlook on some of the research challenges in matching under preferences that the computer science community might seek to tackle over the next decade.
    2:00 P.M.Session 7

    Making it Safe to Use Centralized Markets: Epsilon - Dominant Individual Rationality and Applications to Market Design

    SpeakersBen Roth and Ran Shorrer
    Abstract: A critical, yet under-appreciated feature of market design is that centralized markets operate within a broader context; often market designers cannot force participants to join a centralized market. Well-designed centralized markets must induce participants to join voluntarily, in spite of pre-existing decentralized institutions they may already be using. We take the view that centralizing a market is akin to designing a mechanism to which people may voluntarily sign away their decision rights. We study the ways in which market designers can provide robust incentives that guarantee agents will participate in a centralized market. Our first result is negative and derives from adverse selection concerns. Near any game with at least one pure strategy equilibrium, we prove there is another game in which no mechanism can eliminate the equilibrium of the original game.
    In light of this result we offer a new desideratum for mechanism and market design, which we term epsilon-dominant individual rationality. After noting its robustness, we establish two positive results about centralizing large markets. The first offers a novel justification for stable matching mechanisms and an insight to guide their design to achieve epsilon-dominant individual rationality. Our second result demonstrates that in large games, any mechanism with the property that every player wants to use it conditional on sufficiently many others using it as well can be modified to satisfy epsilon-dominant individual rationality while preserving its behavior conditional on sufficient participation. The modification relies on a class of mechanisms we refer to as random threshold mechanisms and resembles insights from the differential privacy literature.
    3.40 P.M.Break
    4:00 P.M.Session 8
    5.20 P.M.Break
    5.30 P.M.Invited Talk 4 — Marek Pycia, UCLA

    Invariance and Matching Market Outcomes

    Abstract: The empirical studies of school choice provide evidence that standard measures of admission outcomes are the same for many Pareto efficient mechanisms that determine the market allocation based on ordinal rankings of individual outcomes. The paper shows that two factors drive this intriguing puzzle: market size and the invariance properties of the measures for which the regularity has been documented. In addition, the talk will explore the consequences of these findings: the usefulness of non-invariant outcome measures and of mechanisms that elicit preference intensities.
    6.15 P.M.Closing Remarks
    6.30 P.M.END