Erin C. Hall

Association of Race and Age With Survival Among Patients Undergoing Dialysis

CONTEXT Many studies have reported that black individuals undergoing dialysis survive longer than those who are white. This observation is paradoxical given racial disparities in access to and quality of care, and is inconsistent with observed lower survival among black patients with chronic kidney disease. We hypothesized that age and the competing risk of transplantation modify survival differences by race. OBJECTIVE To estimate death among dialysis patients by race, accounting for age as an effect modifier and kidney transplantation as a competing risk. DESIGN, SETTING, AND PARTICIPANTS An observational cohort study of 1,330,007 incident end-stage renal disease patients as captured in the United States Renal Data System between January 1, 1995, and September 28, 2009 (median potential follow-up time, 6.7 years; range, 1 day-14.8 years). Multivariate age-stratified Cox proportional hazards and competing risk models were constructed to examine death in patients who receive dialysis. MAIN OUTCOME MEASURES Death in black vs white patients who receive dialysis. RESULTS Similar to previous studies, black patients undergoing dialysis had a lower death rate compared with white patients (232,361 deaths [57.1% mortality] vs 585,792 deaths [63.5% mortality], respectively; adjusted hazard ratio [aHR], 0.84; 95% confidence interval [CI], 0.83-0.84; P <.001). However, when stratifying by age and treating kidney transplantation as a competing risk, black patients had significantly higher mortality than their white counterparts at ages 18 to 30 years (27.6% mortality vs 14.2%; aHR, 1.93; 95% CI, 1.84-2.03), 31 to 40 years (37.4% mortality vs 26.8%; aHR, 1.46; 95% CI, 1.41-1.50), and 41 to 50 years (44.8% mortality vs 38.0%; aHR, 1.12; 95% CI, 1.10-1.14; P <.001 for interaction terms between race and each aforementioned age category), as opposed to patients aged 51 to 60 years (51.5% vs 50.9%; aHR, 0.93; 95% CI, 0.92-0.94), 61 to 70 years (64.9% vs 67.2%; aHR, 0.87; 95% CI, 0.86-0.88), 71 to 80 years (76.1% vs 79.7%; aHR, 0.85; 95% CI, 0.84-0.86), and older than 80 years (82.4% vs 83.6%; aHR, 0.87; 95% CI, 0.85-0.88). CONCLUSIONS Overall, among dialysis patients in the United States, there was a lower risk of death for black patients compared with their white counterparts. However, the commonly cited survival advantage for black dialysis patients applies only to older adults, and those younger than 50 years have a higher risk of death.

Frailty and delayed graft function in kidney transplant recipients

The ability to predict outcomes following a kidney transplant is limited by the complex physiologic decline of kidney failure, a latent factor that is difficult to capture using conventional comorbidity assessment. The frailty phenotype is a recently described inflammatory state of increased vulnerability to stressors resulting from decreased physiologic reserve and dysregulation of multiple physiologic systems. We hypothesized that frailty would be associated with delayed graft function, based on putative associations between inflammatory cytokines and graft dysfunction. We prospectively measured frailty in 183 kidney transplant recipients between December 2008 and April 2010. Independent associations between frailty and delayed graft function were analyzed using modified Poisson regression. Preoperative frailty was independently associated with a 1.94-fold increased risk for delayed graft function (95% CI, 1.13-3.36; P = .02). The assessment of frailty may provide further insights into the pathophysiology of allograft dysfunction and may improve our ability to preoperatively risk-stratify kidney transplant recipients.

Cumulative Incidence of Cancer After Solid Organ Transplantation

Solid organ transplantation recipients have elevated cancer incidence. Estimates of absolute cancer risk after transplantation can inform prevention and screening.

Living Kidney Donors Ages 70 and Older: Recipient and Donor Outcomes

BACKGROUND AND OBJECTIVES The profound organ shortage has resulted in longer waiting times and increased mortality for those awaiting kidney transplantation. Consequently, patients are turning to older living donors. It is unclear if an upper age limit for donation should exist, both in terms of recipient and donor outcomes. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS In the United States, 219 healthy adults aged ≥70 have donated kidneys at 80 of 279 transplant centers. Competing risks models with matched controls were used to study the independent association between older donor age and allograft survival, accounting for the competing risk of recipient mortality as well as other transplant factors. RESULTS Among recipients of older live donor allografts, graft loss was significantly higher than matched 50-to 59-year-old live donor allografts (subhazard ratio [SHR] 1.62, 95% confidence interval [CI] 1.16 to 2.28, P = 0.005) but similar to matched nonextended criteria 50-to 59-year-old deceased donor allografts (SHR 1.19, 95% CI 0.87 to 1.63, P = 0.3). Mortality among living kidney donors aged ≥70 was no higher than healthy matched controls drawn from the NHANES-III cohort; in fact, mortality was lower, probably reflecting higher selectivity among older live donors than could be captured in National Health and Nutrition Examination Survey III (NHANES-III; HR 0.37, 95% CI 0.21 to 0.65, P < 0.001). CONCLUSIONS These findings support living donation among older adults but highlight the advantages of finding a younger donor, particularly for younger recipients.

Estimating the Potential Pool of HIV‐Infected Deceased Organ Donors in the United States

Human immunodeficiency virus (HIV) is no longer a contraindication to transplantation. For HIV‐infected patients, HIV‐infected deceased donors (HIVDD) could attenuate the organ shortage and waitlist mortality. However, this practice would violate United States federal law. The goal of this study was to estimate the potential impact of legalizing transplantation of HIV‐infected organs by quantifying the potential pool of HIVDD. Using Nationwide Inpatient Sample (NIS) data, HIV‐infected deaths compatible with donation were enumerated. Using HIV Research Network (HIVRN) data, CD4 count, plasma HIV‐1 RNA level, AIDS‐defining illnesses and causes of death were examined in potential HIVDD. Using UNOS data, evaluated donors who later demonstrated unanticipated HIV infections were studied. From NIS, a yearly average of 534 (range: 481–652) potential HIVDD were identified, with 63 (range: 39–90) kidney‐only, 221 (range: 182–255) liver‐only and 250 (range: 182–342) multiorgan donors. From HIVRN, a yearly average of 494 (range: 441–533) potential HIVDD were identified. Additionally, a yearly average of 20 (range: 11–34) donors with unanticipated HIV infection were identified from UNOS. Deceased HIV‐infected patients represent a potential of approximately 500–600 donors per year for HIV‐infected transplant candidates. In the current era of HIV management, a legal ban on the use of these organs seems unwarranted and likely harmful.

Live Donor Champion: Finding Live Kidney Donors by Separating the Advocate from the Patient

Background Lack of education and reluctance to initiate a conversation about live donor kidney transplantation is a common barrier to finding a donor. Although transplant candidates are often hesitant to discuss their illness, friends or family members are often eager to spread awareness and are empowered by advocating for the candidates. We hypothesized that separating the advocate from the patient is important in identifying live donors. Methods We developed an intervention to train a live donor champion (LDC; a friend, family member, or community member willing to advocate for the candidate) for this advocacy role. We compared outcomes of 15 adult kidney transplant candidates who had no prospective donors and underwent the LDC intervention with 15 matched controls from our waiting list. Results Comfort in initiating a conversation about transplantation increased over time for LDCs. Twenty-five potential donors contacted our center on behalf of LDC participants; four participants achieved live donor kidney transplantation and three additional participants have donors in evaluation, compared with zero among matched controls (P < 0.001). Conclusions Transplant candidates are ill equipped to seek live donors; by separating the advocate from the patient, understandable concerns about initiating conversations are reduced.

Center-Level Factors and Racial Disparities in Living Donor Kidney Transplantation

BACKGROUND On average, African Americans attain living donor kidney transplantation (LDKT) at decreased rates compared with their non-African American counterparts. However, center-level variations in this disparity or the role of center-level factors is unknown. STUDY DESIGN Observational cohort study. SETTING & PARTICIPANTS 247,707 adults registered for first-time kidney transplants from 1995-2007 as reported by the Scientific Registry of Transplant Recipients. PREDICTORS Patient-level factors (age, sex, body mass index, insurance status, education, blood type, and panel-reactive antibody level) were adjusted for in all models. The association of center-level characteristics (number of candidates, transplant volume, LDKT volume, median time to transplant, percentage of African American candidates, percentage of prelisted candidates, and percentage of LDKT) and degree of racial disparity in LDKT was quantified. OUTCOMES Hierarchical multivariate logistic regression models were used to derive center-specific estimates of LDKT attainment in African American versus non-African American candidates. RESULTS Racial parity was not seen at any of the 275 transplant centers in the United States. At centers with the least racial disparity, African Americans had 35% lower odds of receiving LDKT; at centers with the most disparity, African Americans had 76% lower odds. Higher percentages of African American candidates (interaction term, 0.86; P = 0.03) and prelisted candidates (interaction term, 0.80; P = 0.001) at a given center were associated with increased racial disparity at that center. Higher rates of LDKT (interaction term, 1.25; P < 0.001) were associated with less racial disparity. LIMITATIONS Some patient-level factors are not captured, including a given patients pool of potential donors. Geographic disparities in deceased donor availability might affect LDKT rates. Center-level policies and practices are not captured. CONCLUSIONS Racial disparity in attainment of LDKT exists at every transplant center in the country. Centers with higher rates of LDKT attainment for all races had less disparity; these high-performing centers might provide insights into policies that might help address this disparity.

Potential limitations of presumed consent legislation.

A causal link has been proposed between presumed consent (PC) and increased donation; we hypothesized that too much heterogeneity exists in transplantation systems to support this inference. We explored variations in PC implementation and other potential factors affecting donation rates. In-depth interviews were performed with senior transplant physicians from 13 European PC countries. Donation was always discussed with family and would not proceed against objections. Country-specific, nonconsent factors were identified that could explain differences in donation rates. Because the process of donation in PC countries does not differ dramatically from the process in non-PC countries, it seems unlikely that PC alone increases donation rates.

The aggressive phenotype: center-level patterns in the utilization of suboptimal kidneys.

Despite the fact that suboptimal kidneys have worse outcomes, differences in waiting times and wait‐list mortality have led to variations in the use of these kidneys. It is unknown whether aggressive center‐level use of one type of suboptimal graft clusters with aggressive use of other types of suboptimal grafts, and what center characteristics are associated with an overall aggressive phenotype. United Network for Organ Sharing (UNOS) data from 2005 to 2009 for adult kidney transplant recipients was aggregated to the center level. An aggressiveness score was assigned to each center based on usage of suboptimal grafts. Deceased‐donor transplant volume correlated with aggressiveness in lower volume, but not higher volume centers. Aggressive centers were mostly found in regions 2 and 9. Aggressiveness was associated with wait‐list size (RR 1.69, 95% CI 1.20–2.34, p = 0.002), organ shortage (RR 2.30, 95% CI 1.57–3.37, p < 0.001) and waiting times (RR 1.75, 95% CI 1.20–2.57, p = 0.004). No centers in single‐center OPOs were classified as aggressive. In cluster analysis, the most aggressive centers were aggressive in all metrics and vice versa; however, centers with intermediate aggressiveness had phenotypic patterns in their usage of suboptimal kidneys. In conclusion, wait‐list size, waiting times, geographic region and OPO competition seem to be driving factors in center‐level aggressiveness.

Effect of Eliminating Priority Points for HLA-B Matching on Racial Disparities in Kidney Transplant Rates

BACKGROUND African Americans have lower rates of obtaining a deceased donor kidney transplant (DDKT) compared with their white counterparts. One proposed mechanism is differential HLA distributions between African Americans and whites. In May 2003, the United Network for Organ Sharing/Organ Procurement and Transplantation Network changed kidney allocation policy to eliminate priority based on HLA-B matching in an effort to address this disparity. The objective of this study was to quantify the effect of the change in policy regarding priority points for HLA-B matching. STUDY DESIGN Observational cohort study. SETTING & PARTICIPANTS A cohort of 178,902 patients registered for a DDKT between January 2000 and August 2009. FACTORS African Americans versus whites before and after the policy change. Cox models were adjusted for age, sex, diabetes, dialysis type, insurance status, education, panel-reactive antibody level, and blood type. OUTCOMES Adjusted relative rates (aRRs) of deceased donor kidney transplant for African Americans compared with whites. MEASUREMENTS Time from initial active wait listing to DDKT, censored for living donor kidney transplant and death. RESULTS Before the policy change, African Americans had 37% lower rates of DDKT (aRR, 0.63; 95% CI, 0.60-0.65; P < 0.001). After the policy change, African Americans had 23% lower rates of DDKT (aRR, 0.77; 95% CI, 0.76-0.79; P < 0.001). There was a 23% reduction in the disparity between African Americans and whites after the policy change (interaction aRR, 1.23; 95% CI, 1.18-1.29; P < 0.001). LIMITATIONS As an observational study, findings could have been affected by residual confounding or other changes in practice patterns. CONCLUSIONS Racial disparity in rates of DDKT was decreased by the HLA-B policy change, but parity was not achieved. There are unaddressed factors in kidney allocation that lead to continued disparity on the kidney transplant waiting list.