Practices and barriers in long-term living kidney donor follow-up: a survey of U.S. transplant centers

Living donor practices in the United States

Living kidney donation is a common procedure in the United States. Substantial variation exists between transplant centers in their protocols and exclusion criteria for potential living donors. In the absence of clinical trial data to guide decisions about exclusion criteria, knowledge of current practices is an important first step in guiding the formulation of donor protocols and future studies. Certain trends in living donation practices have become apparent from surveys of transplant programs over the past few decades. Over the past 25 years, opposition to living unrelated donation in the United States has gone from strong to essentially nonexistent. With respect to donor age, programs have become less strict regarding upper age limits but stricter regarding younger donor candidates. Protocols regarding kidney function, blood pressure, and diabetes screening also continue to evolve. Although donor follow-up is mandated by the Organ Procurement and Transplantation Network for 2 years after donation, a majority of donors are lost to follow-up by 1 year. The most commonly cited barriers to donor follow-up include donor inconvenience, cost issues including reimbursement to care providers, and direct and indirect costs to donors. In this article, we review the current knowledge about living donor practices in the United States.

Risks and outcomes of living donation

Living donors supply approximately 40% of renal allografts in the United States. Based on current data, perioperative mortality after donor nephrectomy is approximately 3 per 10,000 cases, and major and minor perioperative complications affect approximately 3% to 6% and 22% of donors, respectively. Donor nephrectomy does not appear to increase long-term mortality compared with controls, nor does it appear to increase ESRD risk among white donors. Within the donor population, the likelihood of postdonation chronic renal failure and medical comorbidities such as hypertension and diabetes appears to be relatively higher among some donor subgroups, such as African Americans and obese donors, but the impact of uninephrectomy on the lifetime risks of adverse events expected without nephrectomy in these subgroups has not yet been defined. As national follow-up of living donors in the United States is limited in scope, duration, and completeness, additional methods for quantifying risk among diverse living donors are needed. In addition to improved national collection of follow-up data, possible sources of information on donor outcomes may include focused studies with carefully defined control groups, and database integration projects that link national donor registration records to other data sources. Given the growth and evolving characteristics of the living donor population, as well as changes in surgical techniques, tracking of short- and long-term risks after living kidney donation is vital to support truly informed consent and to maintain public trust in living donation. The transplant community must persist in their efforts to accurately assess risk across demographically diverse living kidney donors.

The living kidney donor evaluation: focus on renal issues

Living kidney donor evaluations and follow-up have previously been addressed mostly by transplant physicians and surgeons. However, this area is significantly informed by basic principles of renal physiology and is of increasing clinical interest to general nephrologists. The general nephrology community is increasingly involved in evaluating the suitability of potential donors and in following them after donation when questions are raised about low GFR, hypertension, and other renal concerns. This article focuses on some of the most central and common issues that arise in evaluating potential donors and attempts to provide guidance on the basis of our review of the living donor literature, extrapolations from the general nephrology literature, and our own clinical experience.

When good intentions are not enough: obtaining follow-up data in living kidney donors

The Organ Procurement Transplant Network/United Network for Organ Sharing (OPTN/UNOS) has increased the amount of data collected before and after donation and increased the duration of donor follow-up to 2 years, yet there is evidence that reporting is incomplete. We examined the frequency of missing data in the OPTN/UNOS donor follow-up registry and found that reporting rates were low, particularly for donors who may have limited access to health care. We argue that a national donor follow-up registry is essential to ensure transparency in ascertaining long-term health outcomes among all living donors and in providing assessments of quality assurance within transplant programs. We have suggested approaches to strengthen the donor follow-up registry system. These include setting clear and high standards for follow-up reporting, a system of incentives and penalties that would motivate transplant centers to comply with these standards and would encourage donors to follow-up and lifelong follow-up reporting by primary care providers. We argue that the US government must provide funding to support a donor follow-up registry that can allow for meaningful and valid conclusions, in recognition of donors' public service and to maintain trust in the system of living organ donation.

Living kidney donor follow-up: state-of-the-art and future directions, conference summary and recommendations

In light of continued uncertainty regarding postkidney donation medical, psychosocial and socioeconomic outcomes for traditional living donors and especially for donors meeting more relaxed acceptance criteria, a meeting was held in September 2010 to (1) review limitations of existing data on outcomes of living kidney donors; (2) assess and define the need for long-term follow-up of living kidney donors; (3) identify the potential system requirements, infrastructure and costs of long-term follow-up for living kidney donor outcomes in the United States and (4) explore practical options for future development and funding of United States living kidney donor data collection, metrics and endpoints. Conference participants included prior kidney donors, physicians, surgeons, medical ethicists, social scientists, donor coordinators, social workers, independent donor advocates and representatives of payer organizations and the federal government. The findings and recommendations generated at this meeting are presented.

Racial variation in medical outcomes among living kidney donors

BACKGROUND

Data regarding health outcomes among living kidney donors are lacking, especially among nonwhite persons.

METHODS

We linked identifiers from the Organ Procurement and Transplantation Network (OPTN) with administrative data of a private U.S. health insurer and performed a retrospective study of 4650 persons who had been living kidney donors from October 1987 through July 2007 and who had post-donation nephrectomy benefits with this insurer at some point from 2000 through 2007. We ascertained post-nephrectomy medical diagnoses and conditions requiring medical treatment from billing claims. Cox regression analyses with left and right censoring to account for observed periods of insurance benefits were used to estimate absolute prevalence and prevalence ratios for diagnoses after nephrectomy. We then compared prevalence patterns with those in the 2005-2006 National Health and Nutrition Examination Survey (NHANES) for the general population.

RESULTS

Among the donors, 76.3% were white, 13.1% black, 8.2% Hispanic, and 2.4% another race or ethnic group. The median time from donation to the end of insurance benefits was 7.7 years. After kidney donation, black donors, as compared with white donors, had an increased risk of hypertension (adjusted hazard ratio, 1.52; 95% confidence interval [CI], 1.23 to 1.88), diabetes mellitus requiring drug therapy (adjusted hazard ratio, 2.31; 95% CI, 1.33 to 3.98), and chronic kidney disease (adjusted hazard ratio, 2.32; 95% CI, 1.48 to 3.62); findings were similar for Hispanic donors. The absolute prevalence of diabetes among all donors did not exceed that in the general population, but the prevalence of hypertension exceeded NHANES estimates in some subgroups. End-stage renal disease was identified in less than 1% of donors but was more common among black donors than among white donors.

CONCLUSIONS

As in the general U.S. population, racial disparities in medical conditions occur among living kidney donors. Increased attention to health outcomes among demographically diverse kidney donors is needed. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others.)