Geographic Determinants of Access to Pediatric Deceased Donor Kidney Transplantation

Children receive priority in the allocation of deceased donor kidneys for transplantation in the United States, but because allocation begins locally, geographic differences in population and organ supply may enable variation in pediatric access to transplantation. We assembled a cohort of 3764 individual listings for pediatric kidney transplantation in 2005–2010. For each donor service area, we assigned a category of short (<180 days), medium (181–270 days), or long (>270 days) median waiting time and calculated the ratio of pediatric-quality kidneys to pediatric candidates and the percentage of these kidneys locally diverted to adults. We used multivariable Cox regression analyses to examine the association between donor service area characteristics and time to deceased donor kidney transplantation. The Kaplan–Meier estimate of median waiting time to transplantation was 284 days (95% confidence interval, 263 to 300 days) and varied from 14 to 1313 days across donor service areas. Overall, 29% of pediatric-quality kidneys were locally diverted to adults. Compared with areas with short waiting times, areas with long waiting times had a lower ratio of pediatric-quality kidneys to candidates (3.1 versus 5.9; P<0.001) and more diversions to adults (31% versus 27%; P<0.001). In multivariable regression, a lower kidney to candidate ratio remained associated with longer waiting time (hazard ratio, 0.56 for areas with <2:1 versus reference areas with ≥5:1 kidneys/candidates; P<0.01). Large geographic variation in waiting time for pediatric deceased donor kidney transplantation exists and is highly associated with local supply and demand factors. Future organ allocation policy should address this geographic inequity.Compared with dialysis, kidney transplantation confers significant survival and quality of life benefits for children with ESRD, while offering time-sensitive opportunities for growth and psychosocial development.¹ In the United States, the Organ Procurement and Transplantation Network (OPTN) has responsibility for allocating deceased donor organs for transplantation. Recognizing the unique benefits of transplantation for children, the OPTN implemented the “Share 35” policy in 2005. This policy gives a high priority to pediatric candidates (aged<18 years at listing) when allocating kidneys from local deceased donors aged<35 years.² However, two features of the allocation system create substantial potential for geographic variation in pediatric waiting time for a deceased donor kidney transplant (DDKT). First, certain categories of adult candidates receive even higher priority than children. Second, kidneys are usually allocated to children and adults locally before being offered to children in other areas.²Federal law and guidelines direct the OPTN to allocate organs in a way that is efficient and equitable. The National Organ Transplant Act also acknowledges the unique benefits of transplantation for pediatric patients.^3,4 Despite this acknowledgment, at least three categories of adults may divert a high-quality kidney from pediatric candidates.² An adult candidate for multiorgan transplantation (MOT) can get maximum priority for a kidney if that candidate has been designated to receive another organ from the same donor. Because of a lack of widely accepted clinical criteria for MOT, rates of MOT (e.g., liver-kidney transplantation) vary widely between centers.⁵ Second, an adult with antibodies against human leukocyte antigens (HLAs) can receive higher priority for a biologically compatible kidney allograft than pediatric candidates. Lastly, an adult who is a zero antigen mismatch with a donated kidney can take priority over a pediatric candidate.²Although federal regulations stipulate that organ allocation should not depend on a candidate’s location, kidney allocation usually begins locally.⁴ The OPTN created a system of organ procurement organizations (OPOs) to work with transplant centers and local communities in performing deceased donor organ recovery.³ Each OPO serves a geographically defined donor service area (DSA). DSAs vary widely in size, population characteristics, and in the volume of donated organs.⁶ A kidney is usually offered first to transplant candidates in the DSA where it was procured before being offered to candidates elsewhere.The aim of this study was to examine whether geographic variation in patient-level and DSA-level factors influences pediatric waiting time for DDKT. At the DSA level, we hypothesized that longer waiting time for DDKT would be associated with (1) lower ratios of high-quality kidneys to pediatric candidates and (2) higher rates of diversions of high-quality kidneys to adult candidates.