Increasing the pool of deceased donor organs for kidney transplantation

Impact of Membrane Voltage on Formation and Stability of Human Renal Proximal Tubules in Vitro

More than 15% of adults in the United States suffer from some form of chronic kidney disease (CKD). Current strategies for CKD consist of dialysis or kidney transplant, which, however, can take several years. In this light, tissue engineering and regenerative medicine approaches are the key to improving people's living conditions by advancing previous tissue engineering approaches and seeking new targets as intervention methods for kidney repair or replacement. The membrane voltage (V_m) dynamics of a cell have been associated with cell migration, cell cycle progression, differentiation, and pattern formation. Furthermore, bioelectrical stimuli have been used as a means in the treatment of diseases and wound healing. Here, we investigated the role of V_m as a novel target to guide and manipulate in vitro renal tissue models. Human-immortalized renal proximal tubule epithelial cells (RPTECs-TERT1) were cultured on Matrigel to support the formation of 3D proximal tubular-like structures with the incorporation of a voltage-sensitive dye indicator─bis-(1,3-dibutylbarbituric acid)timethine oxonol (DiBAC). The results demonstrated a correlation between the depolarization and the reorganization of human renal proximal tubule cells, indicating V_m as a candidate variable to control these events. Accordingly, V_m was pharmacologically manipulated using glibenclamide and pinacidil, K_ATP channel modulators, and proximal tubule formation and tubule stability over 21 days were assessed. Chronic manipulation of K_ATP channels induced changes in the tubular network topology without affecting lumen formation. Thus, a relationship was found between the preluminal tubulogenesis phase and K_ATP channels. This relationship may provide future options as a control point during kidney tissue development, treatment, and regeneration goals.

Predicting Kidney Graft Survival Using Machine Learning Methods: Prediction Model Development and Feature Significance Analysis Study

BACKGROUND

Kidney transplantation is the optimal treatment for patients with end-stage renal disease. Short- and long-term kidney graft survival is influenced by a number of donor and recipient factors. Predicting the success of kidney transplantation is important for optimizing kidney allocation.

OBJECTIVE

The aim of this study was to predict the risk of kidney graft failure across three temporal cohorts (within 1 year, within 5 years, and after 5 years following a transplant) based on donor and recipient characteristics. We analyzed a large data set comprising over 50,000 kidney transplants covering an approximate 20-year period.

METHODS

We applied machine learning-based classification algorithms to develop prediction models for the risk of graft failure for three different temporal cohorts. Deep learning-based autoencoders were applied for data dimensionality reduction, which improved the prediction performance. The influence of features on graft survival for each cohort was studied by investigating a new nonoverlapping patient stratification approach.

RESULTS

Our models predicted graft survival with area under the curve scores of 82% within 1 year, 69% within 5 years, and 81% within 17 years. The feature importance analysis elucidated the varying influence of clinical features on graft survival across the three different temporal cohorts.

CONCLUSIONS

In this study, we applied machine learning to develop risk prediction models for graft failure that demonstrated a high level of prediction performance. Acknowledging that these models performed better than those reported in the literature for existing risk prediction tools, future studies will focus on how best to incorporate these prediction models into clinical care algorithms to optimize the long-term health of kidney recipients.

The impact of country reimbursement programmes on living kidney donations

INTRODUCTION

Living-donor kidney transplantation is the gold standard treatment for patients with end-stage kidney disease. However, potential donors ubiquitously face financial as well as logistical barriers. To remove these disincentives from living kidney donations, the governments of 23 countries have implemented reimbursement programmes that shift the burdens of non-medical costs from donors to the governments or private entities. However, scientific evidence for the effectiveness of these programmes is scarce. The present study investigates whether these reimbursement programmes designed to ease the financial and logistical barriers succeeded in increasing the number of living kidney donations at the country level. The study examined within-country variations in the timing of such reimbursement programmes.

METHOD

The study applied the difference-in-difference (two-way panel fixed-effect) technique on the Poisson distribution to estimate the effects of these reimbursement programmes on a 17 year long (2000-2016) dataset covering 109 countries where living donor kidney transplants were performed.

RESULTS

The results indicated that reimbursement programmes have a statistically significant positive effect. Overall, the model predicted that reimbursement programmes increased country-level donation numbers by a factor of 1.12-1.16.

CONCLUSION

Reimbursement programmes may be an effective approach to alleviate the kidney shortage worldwide. Further analysis is warranted on the type of reimbursement programmes and the ethical dimension of each type of such programmes.

Cost-utility analysis in chronic kidney disease patients undergoing kidney transplant; what pays? A systematic review

Background

Health systems are under pressure to deliver more effective care without expansion of resources. This is particularly pertinent to diseases like chronic kidney disease (CKD) that are exacting substantial financial burden to many health systems. The aim of this study is to systematically review the Cost Utility Analysis (CUA) evidence generated across interventions for CKD patients undergoing kidney transplant (KT).

Methods

A systemic review of CUA on the interventions for CKD patients undergoing KT was carried out using a search of the MEDLINE, CINAHL, EMBASE, PsycINFO and NHS-EED. The CHEERS checklist was used as a set of good practice criteria in determining the reporting quality of the economic evaluation. Quality of the data used to inform model parameters was determined using the modified hierarchies of data sources.

Results

A total of 330 articles identified, 16 met the inclusion criteria. Almost all (n = 15) the studies were from high income countries. Out of the 24 characteristics assessed in the CHEERS checklist, more than 80% of the selected studies reported 14 of the characteristics. Reporting of the CUA were characterized by lack of transparency of model assumptions, narrow economic perspective and incomplete assessment of the effect of uncertainty in the model parameters on the results. The data used for the economic model were satisfactory quality. The authors of 13 studies reported the intervention as cost saving and improving quality of life, whereas three studies were cost increasing and improving quality of life. In addition to the baseline analysis, sensitivity analysis was performed in all the evaluations except one. Transplanting certain high-risk donor kidneys (high risk of HIV and Hepatitis-C infected kidneys, HLA mismatched kidneys, high Kidney Donor Profile Index) and a payment to living donors, were found to be cost-effective.

Conclusions

The quality of economic evaluations reviewed in this paper were assessed to be satisfactory. Implementation of these strategies will significantly impact current systems of KT and require a systematic implementation plan and coordinated efforts from relevant stakeholders.

Malignancy after lung transplantation

Lung transplantation is an established therapeutic option for selected patients with advanced lung diseases. As early outcomes after lung transplantation have improved, chronic medical illnesses have emerged as significant obstacles to long-term survival. Among them is post-transplant malignancy, currently representing the 2^nd most common cause of death 5–10 years after transplantation. Chronic immunosuppressive therapy and resulting impairment of anti-tumor immune surveillance is thought to have a central role in cancer development after solid organ transplantation (SOT). Lung transplant recipients receive more immunosuppression than other SOT populations, likely contributing to even higher risk of cancer among this group. The most common cancers in lung transplant recipients are non-melanoma skin cancers, followed by lung cancer and post-transplant lymphoproliferative disorder (PTLD). The purpose of this review is to outline the common malignancies following lung transplant, their risk factors, prognosis and current means for both prevention and treatment.

Machine learning in predicting graft failure following kidney transplantation: A systematic review of published predictive models

INTRODUCTION

Machine learning has been increasingly used to develop predictive models to diagnose different disease conditions. The heterogeneity of the kidney transplant population makes predicting graft outcomes extremely challenging. Several kidney graft outcome prediction models have been developed using machine learning, and are available in the literature. However, a systematic review of machine learning based prediction methods applied to kidney transplant has not been done to date. The main aim of our study was to perform an in-depth systematic analysis of different machine learning methods used to predict graft outcomes among kidney transplant patients, and assess their usefulness as an aid to decision-making.

METHODS

A systemic review of machine learning methods used to predict graft outcomes among kidney transplant patients was carried out using a search of the Medline, the Cumulative Index to Nursing and Allied Health Literature, EMBASE, PsycINFO and Cochrane databases.

RESULTS

A total of 295 articles were identified and extracted. Of these, 18 met the inclusion criteria. Most of the studies were published in the United States after 2010. The population size used to develop the models varied from 80 to 92,844, and the number of features in the models ranged from 6 to 71. The most common machine learning methods used were artificial neural networks, decision trees and Bayesian belief networks. Most of the machine learning based predictive models predicted graft failure with high sensitivity and specificity. Only one machine learning based prediction model had modelled time-to-event (survival) information. Seven studies compared the predictive performance of machine learning models with traditional regression methods and the performance of machine learning methods was found to be mixed, when compared with traditional regression methods.

CONCLUSION

There was a wide variation in the size of the study population and the input variables used. However, the prediction accuracy provided mixed results when machine learning and traditional predictive methods are compared. Based on reported gains in predictive performance, machine learning has the potential to improve kidney transplant outcome prediction and aid medical decision making.

Progenitor/Stem Cell Delivery by Suprarenal Aorta Route in Acute Kidney Injury

Progenitor/stem cell-based kidney regenerative strategies are a key step towards the development of novel therapeutic regimens for kidney disease treatment. However, the route of cell delivery, e.g., intravenous, intra-arterial, or intra-parenchymal, may affect the efficiency for kidney repair in different models of acute and chronic injury. Here, we describe a protocol of intra-aorta progenitor/stem cell injection in rats following either acute ischemia-reperfusion injury or acute proteinuria induced by puromycin aminonucleoside (PAN) – the experimental prototype of human minimal change disease and early stages of focal and segmental glomerulosclerosis. Vascular clips were applied across both renal pedicles for 35 min, or a single dose of PAN was injected via intra-peritoneal route, respectively. Subsequently, 2 x 10⁶ stem cells [green fluorescent protein (GFP)-labeled c-Kit+ progenitor/stem cells or GFP-mesenchymal stem cells] or saline were injected into the suprarenal aorta, above the renal arteries, after application of a vascular clip to the abdominal aorta below the renal arteries. This approach contributed to engraftment rates of ∼10% at day 8 post ischemia-reperfusion injury, when c-Kit+ progenitor/stem cells were injected, which accelerated kidney recovery. Similar rates of engraftment were found after PAN-induced podocyte damage at day 21. With practice and gentle surgical technique, 100% of the rats could be injected successfully, and, in the week following injection, ∼ 85% of the injected rats will recover completely. Given the similarities in mammals, much of the data obtained from intra-arterial delivery of progenitor/stem cells in rodents can be tested in translational research and clinical trials with endovascular catheters in humans.

Barriers to Registration in the National Donor Registry in Nations Using the Opt-In System: A Review of the Literature

BACKGROUND

To increase the number of postmortem organ and tissue donors, donor registries (DRs) have been introduced. The aim of this review was to understand why people in nations with an Opt-in system, who are for or against donation after death, do not register in the DR. Knowing these barriers will help in developing policies to increase the registration rate in the DR.

METHODS

For this review, 2 authors independently assessed the eligibility of the identified studies from 2000 to 2015 in the Pubmed- Medline database. Included were observational and interventional studies concerned with reported barriers to residents joining the national DR in Denmark, The Netherlands, and the United Kingdom.

RESULTS

We included 15 relevant articles for the review. The main barriers to signing the DR in nations using the Opt-in system were: religion; medical mistrust, anxiety, and affective emotions; lack of information; concern about insufficient time to mourn, and that the funeral may be delayed and the deceased not look presentable; physical integrity; ignorance about how to register in the DR; own benefit; and social status.

CONCLUSIONS

The outcome suggests that the main barriers to enrolling in the DR are based on people's doubts about their own ability to perform the registration and cope with the consequences, knowledge, outcome expectations, and concerns about what others will think of them for agreeing to donation. However, not all barriers are easily modifiable, owing to their association with affect or emotions.

Kidney offer acceptance at programs undergoing a Systems Improvement Agreement

In the United States, the Centers for Medicare and Medicaid Services (CMS) use Systems Improvement Agreements (SIAs) to require transplant programs repeatedly flagged for poor-performance to improve performance or lose CMS funding for transplants. We identified 14 kidney transplant (KT) programs with SIAs and 28 KT programs without SIAs matched on waitlist volume and characterized kidney acceptance using SRTR data from 12/2006-3/2015. We used difference-in-differences linear regression models to identify changes in acceptance associated with an SIA independent of program variation and trends prior to the SIA. SIA programs accepted 26.9% and 22.1% of offers pre- and post-SIA, while non-SIA programs accepted 33.9% and 44.4% of offers in matched time periods. After adjustment for donor characteristics, time-varying waitlist volume, and secular trends, SIAs were associated with a 5.9 percentage-point (22%) decrease in kidney acceptance (95% CI: -10.9 to -0.8, P = .03). The decrease in acceptance post-SIA was more pronounced for KDPI 0-40 kidneys (12.3 percentage-point decrease, P = .007); reductions in acceptance of higher KDPI kidneys occurred pre-SIA. Programs undergoing SIAs substantially reduced acceptance of kidney offers for waitlisted candidates. Attempts to improve posttransplant outcomes might have the unintended consequence of reducing access to transplantation as programs adopt more restrictive organ selection practices.

Outcomes of Organ Transplantation from Donors with a Cancer History

Background

The inherent challenges of selecting an acceptable donor for the increasing number and acuity of recipients has forced programs to take increased risks, including accepting donors with a cancer history (DWCH). Outcomes of organ transplantation using organs from DWCH must be clarified. We assessed transplant outcomes of recipients of organs from DWCH.

Material/Methods

Retrospective analysis of the Scientific Registry of Transplant Recipients data from January 1, 2000 to December 31, 2014 identified 8385 cases of transplants from DWCH. A Cox-proportional hazard regression model and log-rank test were used to compare patient survival and hazard levels of various cancer types.

Results

DWCH was an independent risk factor of 5-year patient survival (HR=1.089, 95% CI: 1.009–1.176, P=0.03) and graft survival (HR=1.129, 95% CI: 1.056–1.208, P<0.01) in liver and heart transplantation (patient survival: HR=1.112, 95% CI: 1.057–1.170, P<0.01; graft survival: HR=1.244, 95% CI: 1.052–1.472, P=0.01). There was no remarkable difference between the 2 groups in kidney and lung transplantation. Donors with genitourinary and gastrointestinal cancers were associated with inferior outcomes in kidney transplantation. Transplantation from donors with central nervous system cancer resulted in poorer survival in liver transplant recipients. Recipients of organs from donors with hematologic malignancy and otorhinolaryngologic cancer had poorer survival following heart transplantation.

Conclusions

Under the current donor selection criteria, recipients of organs from DWCH had inferior outcomes in liver and heart transplantation, whereas organs from DWCH were safely applied in kidney and lung transplantation. Specific cancer types should be cautiously evaluated before performing certain types of organ transplantation.

Zero-Time Renal Transplant Biopsies: A Comprehensive Review

Zero-time kidney biopsies, obtained at time of transplantation, are performed in many transplant centers worldwide. Decisions on kidney discard, kidney allocation, and choice of peritransplant and posttransplant treatment are sometimes based on the histological information obtained from these biopsies. This comprehensive review evaluates the practical considerations of performing zero-time biopsies, the predictive performance of zero-time histology and composite histological scores, and the clinical utility of these biopsies. The predictive performance of individual histological lesions and of composite scores for posttransplant outcome is at best moderate. No single histological lesion or composite score is sufficiently robust to be included in algorithms for kidney discard. Dual kidney transplantation has been based on histological assessment of zero-time biopsies and improves outcome in individual patients, but the waitlist effects of this strategy remain obscure. Zero-time biopsies are valuable for clinical and translational research purposes, providing insight in risk factors for posttransplant events, and as baseline for comparison with posttransplant histology. The molecular phenotype of zero-time biopsies yields novel therapeutic targets for improvement of donor selection, peritransplant management and kidney preservation. It remains however highly unclear whether the molecular expression variation in zero-time biopsies could become a better predictor for posttransplant outcome than donor/recipient baseline demographic factors.

Reducing the costs of chronic kidney disease while delivering quality health care: a call to action

The treatment of chronic kidney disease (CKD) and of end-stage renal disease (ESRD) imposes substantial societal costs. Expenditure is highest for renal replacement therapy (RRT), especially in-hospital haemodialysis. Redirection towards less expensive forms of RRT (peritoneal dialysis, home haemodialysis) or kidney transplantation should decrease financial pressure. However, costs for CKD are not limited to RRT, but also include nonrenal health-care costs, costs not related to health care, and costs for patients with CKD who are not yet receiving RRT. Even if patients with CKD or ESRD could be given the least expensive therapies, costs would decrease only marginally. We therefore propose a consistent and sustainable approach focusing on prevention. Before a preventive strategy is favoured, however, authorities should carefully analyse the cost to benefit ratio of each strategy. Primary prevention of CKD is more important than secondary prevention, as many other related chronic diseases, such as diabetes mellitus, hypertension, cardiovascular disease, liver disease, cancer, and pulmonary disorders could also be prevented. Primary prevention largely consists of lifestyle changes that will reduce global societal costs and, more importantly, result in a healthy, active, and long-lived population. Nephrologists need to collaborate closely with other sectors and governments, to reach these aims.

Continuous Normothermic Ex Vivo Kidney Perfusion Improves Graft Function in Donation After Circulatory Death Pig Kidney Transplantation

BACKGROUND

Donation after circulatory death (DCD) is current clinical practice to increase the donor pool. Deleterious effects on renal graft function are described for hypothermic preservation. Therefore, current research focuses on investigating alternative preservation techniques, such as normothermic perfusion.

METHODS

We compared continuous pressure-controlled normothermic ex vivo kidney perfusion (NEVKP) with static cold storage (SCS) in a porcine model of DCD autotransplantation. After 30 minutes of warm ischemia, right kidneys were removed from 30-kg Yorkshire pigs and preserved with 8-hour NEVKP or in 4°C histidine-tryptophan-ketoglutarate solution (SCS), followed by kidney autotransplantation.

RESULTS

Throughout NEVKP, electrolytes and pH values were maintained. Intrarenal resistance decreased over the course of perfusion (0 hour, 1.6 ± 0.51 mm per minute vs 7 hours, 0.34 ± 0.05 mm Hg/mL per minute, P = 0.005). Perfusate lactate concentration also decreased (0 hour, 10.5 ± 0.8 vs 7 hours, 1.4 ± 0.3 mmol/L, P < 0.001). Cellular injury markers lactate dehydrogenase and aspartate aminotransferase were persistently low (lactate dehydrogenase < 100 U/L, below analyzer range; aspartate aminotransferase 0 hour, 15.6 ± 9.3 U/L vs 7 hours, 24.8 ± 14.6 U/L, P = 0.298). After autotransplantation, renal grafts preserved with NEVKP demonstrated lower serum creatinine on days 1 to 7 (P < 0.05) and lower peak values (NEVKP, 5.5 ± 1.7 mg/dL vs SCS, 11.1 ± 2.1 mg/dL, P = 0.002). The creatinine clearance on day 4 was increased in NEVKP-preserved kidneys (NEVKP, 39 ± 6.4 vs SCS, 18 ± 10.6 mL/min; P = 0.012). Serum neutrophil gelatinase-associated lipocalin at day 3 was lower in the NEVKP group (1267 ± 372 vs 2697 ± 1145 ng/mL, P = 0.029).

CONCLUSIONS

Continuous pressure-controlled NEVKP improves renal function in DCD kidney transplantation. Normothermic ex vivo kidney perfusion might help to decrease posttransplant delayed graft function rates and to increase the donor pool.

Cost of renal replacement: how to help as many as possible while keeping expenses reasonable?

The treatment of kidney diseases consumes a substantial amount of the health budget for a relatively small fraction of the overall population. If the nephrological community and society do not develop mechanisms to contain those costs, it will become impossible to continue assuring optimal outcomes and quality of life while treating all patients who need it. In this article, we describe several mechanisms to maintain sustainability of renal replacement therapy. These include (i) encouragement of transplantation after both living and deceased donation; (ii) stimulation of alternative dialysis strategies besides classical hospital haemodialysis, such as home haemodialysis, peritoneal dialysis or self-care and necessitating less reimbursement; (iii) promotion of educational activities guiding the patients towards therapies that are most suited for them; (iv) consideration of one or more of cost containment incentives such as bundling of reimbursement (if not affecting quality of the treatment), timely patient referral, green dialysis, start of dialysis based on clinical necessity rather than renal function parameters and/or prevention of CKD or its progression; (v) strategically planned adaptations to the expected growth of the ageing population in need of renal replacement; (vi) the necessity for support of research in the direction of helping as large as possible patient populations for acceptable costs; and (vii) the need for more patient-centred approaches. We also extend the discussion to the specific situation of kidney diseases in low- and middle-income countries. Finally, we point to the dramatic differences in accessibility and reimbursement of different modalities throughout Europe. We hope that this text will offer a framework for the nephrological community, including patients and nurses, and the concerned policy makers and caregivers on how to continue reaching all patients in need of renal replacement for affordable expenses.

Increasing the supply of kidneys for transplantation by making living donors the preferred source of donor kidneys

At the present time, increasing the use of living donors offers the best solution to the organ shortage problem. The clinical questions raised when the first living donor kidney transplant was performed, involving donor risk, informed consent, donor protection, and organ quality, have been largely answered. We strongly encourage a wider utilization of living donation and recommend that living donation, rather than deceased donation, become the first choice for kidney transplantation. We believe that it is ethically sound to have living kidney donation as the primary source for organs when the mortality and morbidity risks to the donor are known and kept extremely low, when the donor is properly informed and protected from coercion, and when accepted national and local guidelines for living donation are followed.

Preimplant histologic acute tubular necrosis and allograft outcomes

BACKGROUND AND OBJECTIVES

The influence of deceased-donor AKI on post-transplant outcomes is poorly understood. The few published studies about deceased-donor preimplant biopsy have reported conflicting results regarding associations between AKI and recipient outcomes.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This multicenter study aimed to evaluate associations between deceased-donor biopsy reports of acute tubular necrosis (ATN) and delayed graft function (DGF), and secondarily for death-censored graft failure, first adjusting for the kidney donor risk index and then stratifying by donation after cardiac death (DCD) status.

RESULTS

Between March 2010 and April 2012, 651 kidneys (369 donors, 4 organ procurement organizations) were biopsied and subsequently transplanted, with ATN reported in 110 (17%). There were 262 recipients (40%) who experienced DGF and 38 (6%) who experienced graft failure. DGF occurred in 45% of kidneys with reported ATN compared with 39% without ATN (P=0.31) resulting in a relative risk (RR) of 1.13 (95% confidence interval [95% CI], 0.9 to 1.43) and a kidney donor risk index-adjusted RR of 1.11 (95% CI, 0.88 to 1.41). There was no significant difference in graft failure for kidneys with versus without ATN (8% versus 5%). In stratified analyses, the adjusted RR for DGF with ATN was 0.97 (95% CI, 0.7 to 1.34) for non-DCD kidneys and 1.59 (95% CI, 1.23 to 2.06) for DCD kidneys (P=0.02 for the interaction between ATN and DCD on the development of DGF).

CONCLUSIONS

Despite a modest association with DGF for DCD kidneys, this study reveals no significant associations overall between preimplant biopsy-reported ATN and the outcomes of DGF or graft failure. The potential benefit of more rigorous ATN reporting is unclear, but these findings provide little evidence to suggest that current ATN reports are useful for predicting graft outcomes or deciding to accept or reject allograft offers.

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.

Validity of physician billing claims to identify deceased organ donors in large healthcare databases

Objective

We evaluated the validity of physician billing claims to identify deceased organ donors in large provincial healthcare databases.

Methods

We conducted a population-based retrospective validation study of all deceased donors in Ontario, Canada from 2006 to 2011 (n = 988). We included all registered deaths during the same period (n = 458,074). Our main outcome measures included sensitivity, specificity, positive predictive value, and negative predictive value of various algorithms consisting of physician billing claims to identify deceased organ donors and organ-specific donors compared to a reference standard of medical chart abstraction.

Results

The best performing algorithm consisted of any one of 10 different physician billing claims. This algorithm had a sensitivity of 75.4% (95% CI: 72.6% to 78.0%) and a positive predictive value of 77.4% (95% CI: 74.7% to 80.0%) for the identification of deceased organ donors. As expected, specificity and negative predictive value were near 100%. The number of organ donors identified by the algorithm each year was similar to the expected value, and this included the pre-validation period (1991 to 2005). Algorithms to identify organ–specific donors performed poorly (e.g. sensitivity ranged from 0% for small intestine to 67% for heart; positive predictive values ranged from 0% for small intestine to 37% for heart).

Interpretation

Primary data abstraction to identify deceased organ donors should be used whenever possible, particularly for the detection of organ-specific donations. The limitations of physician billing claims should be considered whenever they are used.

Liver transplantation: past, present and future

The first human liver transplant operation was performed by Thomas Starzl in 1963. The next two decades were marked by difficulties with donor organ quality, recipient selection, operative and perioperative management, immunosuppression and infectious complications. Advances in each of these areas transformed liver transplantation from an experimental procedure to a standard treatment for end-stage liver disease and certain cancers. From the handful of pioneering programmes, liver transplantation has expanded to hundreds of programmes in >80 countries. 1-year patient survival rates have exceeded 80% and outcomes continue to improve. This success has created obstacles. Ongoing challenges of liver transplantation include those concerning donor organ shortages, recipients with more advanced disease at transplant, growing need for retransplantation, toxicities and adverse effects associated with long-term immunosuppression, obesity and NASH epidemics, HCV recurrence and the still inscrutable biology of hepatocellular carcinoma. This Perspectives summarizes this transformation over time and details some of the challenges ahead.

Deceased organ donation consent rates among racial and ethnic minorities and older potential donors

OBJECTIVES

We sought to assess consent rates for organ donation from potential brain-dead donors, and to identify factors associated with variation in consent for donation that could guide the development of targeted interventions to increase organ consent rates.

DESIGN, SETTING, AND SUBJECTS

We used data provided by the Organ Procurement and Transplantation Network to analyze the 35,823 organ procurement organization-reported eligible deaths (potential brain-dead donors ≤ 70 yr of age) from January 1, 2008, to October 31, 2011.

MEASUREMENTS AND MAIN RESULTS

Excluding cases where donation authorization was based on prior patient documentation (e.g., donor registry), consent was obtained on 21,601 (68.9%), not obtained on 8,727 (27.8%), and not requested on 1,080 (3.4%) eligible deaths. There were substantial differences in consent rates among racial/ethnic groups (77.0% in whites, 67.5% in Hispanics, 54.9% in blacks, and 48.1% in Asians) and organ procurement organizations (median [interquartile range]: 72.4% [67.5-87.3]). In generalized estimating equation models, with whites and patients ages 18-39 yr as the respective reference groups, consent for donation was less likely to be obtained among Hispanics (odds ratio 0.54; 95% confidence interval 0.44-0.65), blacks (odds ratio 0.35; 95% confidence interval 0.31-0.39), Asians (odds ratio 0.31; 95% confidence interval 0.25-0.37), and eligible donors ages 55-64 (odds ratio 0.72; 95% confidence interval 0.67-0.77), and ≥ 65 yr (odds ratio 0.58; 95% confidence interval 0.52-0.64).

CONCLUSIONS

In presenting the first published analyses of consent rates among all eligible deaths, this study confirms smaller and regional studies that showed significant differences in consent rates between whites and racial/ethnic minorities (blacks, Hispanics, and Asians). The study also identifies considerable variation in consent rates between age groups and between organ procurement organizations. Critical care physicians are usually the front-line providers for potential brain-dead donors and their next-of-kin, and these data highlight the need for further research to identify the causes of variation in consent rates and mechanisms to increase rates where appropriate.