Which Renal Transplant Candidates Should Accept Marginal Kidneys in Exchange for a Shorter Waiting Time on Dialysis? Jesse D. Schold* † and Herwig-Ulf Meier-Kriesche* Departments of *Medicine and † Health Services Research, Management and Policy, University of Florida, Gainesville, Florida Renal transplantation has been established as a life-saving procedure for patients with ESRD. Deceased donor kidneys convey variable life expectancies for recipients. However, limited information is available to guide patients and patient advocates concerning the appropriateness to list for expanded criteria donations (ECD). Half-lives for wait-listed transplant candidates were estimated from the time of ESRD onset on the basis of recipient age, primary diagnosis, and organ quality using survival models. In addition, we evaluated the likelihood of candidates’ receiving a transplant on the basis of age and other characteristics by duration of waiting time. Older patients (65) had longer life expectancy when they accepted an ECD within 2 yr of ESRD onset (5.6 yr) compared with waiting for a standard kidney (5.3 yr) or a living donation (5.5 yr) after 4 yr of dialysis. Conversely, younger recipients (18 to 39 yr) had longer life expectancy with a living donation (27.6 yr) or standard kidney (26.4 yr) after 4 yr on dialysis compared with an ECD after 2 yr of dialysis (17.6 yr). Increased candidate age was associated with the likelihood of not receiving a transplant during the period on the waiting list as a result of mortality and separately related to morbidity and delisting. Older and frailer transplant candidates benefit from accepting lower quality organs early after ESRD, whereas younger and healthier patients benefit from receiving higher quality organs even with longer dialysis exposure. These findings are important for transplant candidates and advocates decision-making and for potential further implementation in allocation policy. Clin J Am Soc Nephrol 1: 532–538, 2006. doi: 10.2215/CJN.01130905 R enal transplantation has been established as a life- saving procedure for patients who have ESRD and have been medically cleared for the surgical procedure (1). Furthermore, the beneficial effects of transplantation are observed among patient subgroups, including higher risk pa- tients such as those with high body mass index levels and older adults (1,2). Research suggests that even certain candidates who are older than 70 yr may be viable for the procedure and enjoy the benefits of transplantation, including extended life expectancy (3). The notion that transplantation is efficacious relative to remaining on maintenance dialysis also likely has increased the demand for placement on the waiting list. Dial- ysis promotes the development of cardiovascular disease, os- teodystrophy, and anemia among other potential long-term deleterious effects (4,5). Furthermore, the duration of dialysis has been shown to have a significant impact on outcomes after transplantation (6 –11). In addition, transplantation has been shown to halt cardiovascular insults that are attributed to di- alysis (12). This cumulative evidence may suggest that patients should be strongly motivated to acquire a transplant as early in the ESRD process as possible. However, the advantages of kidney transplantation are based on population studies, and patients may have a wide array of circumstances when con- fronted with the need for a kidney transplant. There are mul- tiple procedural, donor, and recipient factors that are potent modifiers for the average advantage of kidney transplantation. One of the strongest predictors of graft and patient survival in deceased donor renal transplantation is the quality of the donor organ (13,14). A varying constellation of factors, most notably the age of the donated organ, ultimately define the quality of a graft and convey highly variable life expectancies for the prospective transplant recipient. A patient who has ESRD onset and is eligible for transplantation is presented with therapeutic options, including seeking a living donation and, if placed on the deceased donor waiting list, whether to accept lower quality organs. The Organ Procurement and Transplan- tation Network instituted a formalized definition of marginal kidneys in 2002 with the advent of the Expanded Criteria Donor (ECD) (15,16). These deceased donor kidneys were dem- onstrated to convey a 70% or greater risk for graft loss for transplant recipients relative to an ideal donation and were characterized by a donor age older than 60 yr or older than 50 Received September 27, 2005. Accepted January 3, 2006. Published online ahead of print. Publication date available at www.cjasn.org. The interpretation and reporting of these data are the responsibility of the authors and in no way should be seen as an official policy of or interpretation by the Scientific Registry of Transplant Recipients or the US government. Institutional review board approval or exemption determination is the responsibility of the authors as well. Address correspondence to: Dr. Jesse Schold, Division of Nephrology, Hyper- tension, and Transplantation, Department of Medicine, College of Medicine, University of Florida, PO Box 100224, Gainesville, FL. Phone: 352-846-2692; Fax: 352-392-5465; E-mail: scholjd@medicine.ufl.edu Copyright © 2006 by the American Society of Nephrology ISSN: 1555-9041/103-0532