Age-Based Preferences in Paired Kidney Exchange

We consider a model of Paired Kidney Exchange (PKE) with feasibility constraints on the number of patient-donor pairs involved in exchanges. Patients' preferences are restricted so that patients prefer kidneys from compatible younger donors to kidneys from older donors. In this framework, patients with compatible donors may enroll on PKE programs to receive an organ with higher expected graft survival than that of their intended donor. PKE rules that satisfy individual rationality, eciency, and strategy-proofness necessarily select pairwise exchanges. Such rules maximize the number of transplantations among pairs with the youngest donors, and sequentially among pairs with donors of dierent age group

Kidney Exchange

Most transplanted kidneys are from cadavers, but there are also substantial numbers of transplants from live donors. Recently, there have started to be kidney exchanges involving two donor-patient pairs such that each donor cannot give a kidney to the intended recipient because of immunological incompatibility, but each patient can receive a kidney from the other donor. Exchanges are also made in which a donor-patient pair makes a donation to someone on the queue for a cadaver kidney, in return for the patient in the pair receiving the highest priority for a compatible cadaver kidney when one becomes available. We explore how such exchanges can be arranged efficiently and incentive compatibly. The problem resembles some of the housing' problems studied in the mechanism design literature for indivisible goods, with the novel feature that while live donor kidneys can be assigned simultaneously, the cadaver kidneys must be transplanted immediately upon becoming available. In addition to studying the theoretical properties of the design we propose for a kidney exchange, we present simulation results suggesting that the welfare gains would be substantial, both in increased number of feasible live donation transplants, and in improved match quality of transplanted kidneys.

'A Better Way to Measure Choices' Discrete Choice Experiment and Conjoint Analysis Studies in Nephrology: A Literature Review

Discrete choice experiments (DCE) and conjoint analysis (CA) are increasingly used to address health policy issues. This is because the DCE and CA approaches have theoretical foundations in the characteristics theory of demand, which assumes goods, services, or healthcare provision, can be valued in terms of their characteristics (or attributes). As a result, such analysis is grounded in economic theory, lending theoretical validity to this approach. With DCEs, respondents are also assumed to act in a utility-maximising manner and make choices contingent upon the levels of attributes in DCE scenarios. Therefore, choice data can be analysed using econometric methods compatible with random utility theory (RUT) or random regret minimisation (RRM) theory. This means they have additional foundations in economic theory. In contrast, analyses described as CAs are sometimes compatible with RUT or RRM, but by definition they do not have to be. In this paper we review the CA/DCE evidence relating to nephrology. The CA/DCE approach is then compared with other approaches used to provide either quality of life information or preference information relating to nephrology. We conclude by providing an assessment of the value of undertaking CA or DCE analysis in nephrology, comparing the application of CA/DCEs in nephrology with other methodological approaches.</p

Feasibility Constraints and Protective Behavior in Efficient Kidney Exchange

We propose a model of Kidney-Exchange that incorporates the main European institutional features. We assume that patients do not consider all compatible kidneys homogeneous and patients are endowed with reservation values over the minimal quality of the kidney they may receive. Under feasibility constraints, patients' truthful revelation of reservation values is incompatible with constrained efficiency. In the light of this result, we introduce an alternative behavioral assumption on patients' incentives. Patients choose their revelation strategies as to “protect” themselves from bad outcomes and use a lexicographic refinement of maximin strategies. In this environment, if exchanges are pairwise, then priority rules or rules that maximize a fixed ordering provide incentives for the patients to report their true reservation values. The positive result vanishes if larger exchanges are admitted.Kidney, Matching, Protective Behavior

Nonsimultaneous Chains and Dominos in Kidney- Paired Donation—Revisited

Since 2008, kidney exchange in America has grown in part from the incorporation of nondirected donors in transplant chains rather than simple exchanges. It is controversial whether these chains should be performed simultaneously ‘domino-paired donation’, (DPD) or nonsimultaneously ‘nonsimultaneous extended altruistic donor, chains (NEAD). NEAD chains create ‘bridge donors’ whose incompatible recipients receive kidneys before the bridge donor donates, and so risk reneging by bridge donors, but offer the opportunity to create more transplants by overcoming logistical barriers inherent in simultaneous chains. Gentry et al. simulated whether DPD or NEAD chains would produce more transplants when chain segment length was limited to three transplants, and reported that DPD performed at least as well as NEAD chains. As this finding contrasts with the experience of several groups involved in kidney-paired donation, we performed simulations that allowed for longer chain segments and used actual patient data from the Alliance for Paired Donation. When chain segments of 4–6 transplants are allowed in the simulations, NEAD chains produce more transplants than DPD. Our simulations showed not only more transplants as chain length increased, but also that NEAD chains produced more transplants for highly sensitized and blood type O recipients.Alliance for Paired DonationNovartis (Firm)Genzyme CorporationF. Hoffmann-La Roche & Co.Pfizer Inc.Astellas Pharma USNational Science Foundation (U.S.) (Grant No. 0616733 to the National Bureau of Economic Research)Life Connection of OhioUniversity of Toled