Table 1.

List of key terminology

Exchange	A proposed kidney transplant between a donor of one incompatible pair with a recipient of a different incompatible pair.
1-way	Synonymous with exchange. Full term would be 1-way exchange.
Cycle	A set of N exchanges in a closed loop found by the matching algorithm in which each recipient receives a kidney from a donor within the cycle.
NEAD segment	A set of N exchanges started by a nondirected donor (NDD) or bridge donor (BD) that ends either in a bridge donor or in donation to the deceased donor waiting list.
NEAD chain	The accumulation of multiple NEAD segments linked together through BD’s and initiated by a NDD.
DPD	A set of N exchanges started by an NDD that occur simultaneously and ends with donation to the deceased donor waiting list.
Offer	A NEAD segment or cycle that has been presented to transplant centers for consideration.
1-way success rate	The number of exchanges completed divided by the total number of exchanges presented in offers.
Offer success rate	The number of offers containing at least 1 successful transplant divided by the total number of offers.