Mortality after kidney transplantation: a comparison between the United States and Canada

Expanding Access to High KDPI Kidney Transplant for Recipients Aged 60 y and Older: Cost Utility and Survival

Background

Modern organ allocation systems are tasked with equitably maximizing the utility of transplanted organs. Increasing the use of deceased donor organs at risk of discard may be a cost-effective strategy to improve overall transplant benefit. We determined the survival implications and cost utility of increasing the use of marginal kidneys in an older adult Canadian population of patients with end-stage kidney disease.

Methods

We constructed a cost-utility model with microsimulation from the perspective of the Canadian single-payer health system for incident transplant waitlisted patients aged 60 y and older. A kidney donor profile index score of ≥86 was considered a marginal kidney. Donor- and recipient-level characteristics encompassed in the kidney donor profile index and estimated posttransplant survival scores were used to derive survival posttransplant. Patients were followed up for 10 y from the date of waitlist initiation. Our analysis compared the routine use of marginal kidneys (marginal kidney scenario) with the current practice of limited use (status quo scenario).

Results

The 10-y mean cost and quality-adjusted life-years per patient in the marginal kidney scenario were estimated at $379 485.33 (SD: $156 872.49) and 4.77 (SD: 1.87). In the status quo scenario, the mean cost and quality-adjusted life-years per patient were $402 937.68 (SD: $168 508.85) and 4.37 (SD: 1.87); thus, the intervention was considered dominant. At 10 y, 62.8% and 57.0% of the respective cohorts in the marginal kidney and status quo scenarios remained alive.

Conclusions

Increasing the use of marginal kidneys in patients with end-stage kidney disease aged 60 y and older may offer cost savings, improved quality of life, and greater patient survival in comparison with usual care.

Survival After Liver Transplantation: An International Comparison Between the United States and the United Kingdom in the Years 2008-2016

BACKGROUND

Compared with the United States, risk-adjusted mortality in the United Kingdom has historically been worse in the first 90 d following liver transplantation (LT) and better thereafter. In the last decade, there has been considerable change in the practice of LT internationally, but no contemporary large-scale international comparison of posttransplant outcomes has been conducted. This study aimed to determine disease-specific short- and long-term mortality of LT recipients in the United States and the United Kingdom.

METHODS

This retrospective international multicenter cohort study analyzed adult (≥18 y) first-time LT recipients between January 2, 2008, and December 31, 2016, using the Organ Procurement and Transplantation Network/United Network for Organ Sharing and the UK Transplant Registry databases. Time-dependent Cox regression estimated hazard ratios (HRs) comparing disease-specific risk-adjusted mortality in the first 90 d post-LT, between 90 d and 1 y, and between 1 and 5 y.

RESULTS

Forty-two thousand eight hundred seventy-four US and 4950 UK LT recipients were included. The main LT indications in the United States and the United Kingdom were hepatocellular carcinoma (25.4% and 24.9%, respectively) and alcohol-related liver disease (20.3% and 27.1%, respectively). There were no differences in mortality during the first 90 d post-LT (reference: United States; HR, 0.96; 95% confidence interval [CI], 0.82-1.12). However, between 90 d and 1 y (HR, 0.71; 95% CI, 0.59-0.85) and 1 and 5 y (HR, 0.71; 95% CI, 0.63-0.81]) the United Kingdom had lower mortality. The mortality differences between 1 and 5 y were most marked in hepatocellular carcinoma (HR, 0.71; 95% CI, 0.58-0.88) and alcohol-related liver disease patients (HR, 0.64; 95% CI, 0.45-0.89).

CONCLUSIONS

Risk-adjusted mortality in the United States and the United Kingdom was similar in the first 90 d post-LT but better in the United Kingdom thereafter. International comparisons of LT may highlight differences in healthcare delivery and help benchmarking by identifying modifiable factors that can facilitate improved global outcomes in LT.

The Role of Registries in Kidney Transplantation Across International Boundaries

Transplant professionals strive to improve domestic kidney transplantation rates safely, cost efficiently, and ethically, but to increase rates further may wish to allow their recipients and donors to traverse international boundaries. Travel for transplantation presents significant challenges to the practice of transplantation medicine and donor medicine, but can be enhanced if sustainable international registries develop to include low- and low-middle income countries. Robust data collection and sharing across registries, linking pretransplant information to post-transplant information, linking donor to recipient information, increasing living donor transplant activity through paired exchange, and ongoing reporting of results to permit flexibility and adaptability to changing clinical environments, will all serve to enhance kidney transplantation across international boundaries.

Risk Factors and Outcomes of Early Hospital Readmission in Canadian Kidney Transplant Recipients: A Population-Based Multi-Center Cohort Study

Background:

Early hospital readmissions (EHRs) occur commonly in kidney transplant recipients. Conflicting evidence exists regarding risk factors and outcomes of EHRs.

Objective:

To determine risk factors and outcomes associated with EHRs (ie, hospitalization within 30 days of discharge from transplant hospitalization) in kidney transplant recipients.

Design:

Population-based cohort study using linked, administrative health care databases.

Setting:

Ontario, Canada.

Patients:

We included 5437 kidney transplant recipients from 2002 to 2015.

Measurements:

Risk factors and outcomes associated with EHRs. We assessed donor, recipient, and transplant risk factors. We also assessed the following outcomes: total graft failure, death-censored graft failure, death with a functioning graft, mortality, and late hospital readmission.

Methods:

We used multivariable logistic regression to examine the association of each risk factor and the odds of EHR. To examine the relationship between EHR status (yes vs no [reference]) and the outcomes associated with EHR (eg, total graft failure), we used a multivariable Cox proportional hazards model.

Results:

In all, 1128 kidney transplant recipients (20.7%) experienced an EHR. We found the following risk factors were associated with an increased risk of EHR: older recipient age, lower income quintile, several comorbidities, longer hospitalization for initial kidney transplant, and older donor age. After adjusting for clinical characteristics, compared to recipients without an EHR, recipients with an EHR had an increased risk of total graft failure (adjusted hazard ratio [aHR]: 1.46, 95% CI: 1.29, 1.65), death-censored graft failure (aHR: 1.62, 95% CI: 1.36, 1.94), death with graft function (aHR: 1.34, 95% CI: 1.13, 1.59), mortality (aHR: 1.41, 95% CI: 1.22, 1.63), and late hospital readmission in the first 0.5 years of follow-up (eg, 0 to <0.25 years: aHR: 2.11, 95% CI: 1.85, 2.40).

Limitations:

We were not able to identify which readmissions could have been preventable and there is a potential for residual confounding.

Conclusions:

Results can be used to identify kidney transplant recipients at risk of EHR and emphasize the need for interventions to reduce the risk of EHRs.

Trial registration:

This is not applicable as this is a population-based cohort study and not a clinical trial.

Comparison of All-Cause Mortality Between Canadian Kidney Transplant Recipients and Patients With Cancer: A Population-Based Cohort Study

Background:

Understanding rates of mortality in kidney transplant recipients relative to other common diseases can enhance our understanding of the mortality burden in kidney transplant recipients.

Objective:

To compare the survival probability in Canadian female and male kidney transplant recipients with patients with common cancers (female: breast, colorectal, lung, or pancreas; male: prostate, colorectal, lung, or pancreas) in a contemporary population.

Design:

Population-based cohort study using linked administrative health care databases.

Setting:

Ontario, Canada.

Patients:

A total of 6888 incident kidney transplant recipients (median age was 50 and 51 years in females and males, respectively) and a total of 532 452 incident patients with cancer (median age range 60 to 72 years across cancer types) from 1997 to 2015.

Measurements:

All-cause mortality.

Methods:

The survival of study participants was described using the Kaplan-Meier product limit estimator. The rate of survival was compared between kidney transplant recipients and patients with cancer using extended Cox regression with a Heaviside function.

Results:

Kidney transplant recipients had a higher survival probability compared with all cancer types. For example, male kidney transplant recipients had a 5-year survival probability of 89.6% (95% confidence interval [CI]: 88.6%-90.5%) compared with 83.3% (95% CI: 83.1%-83.5%) in patients with prostate cancer, and 14.0% (95% CI: 13.7%-14.3%), 56.1% (95% CI: 55.7%-56.5%), and 9.1% (95% CI: 8.5%-9.7%) in patients with lung, colorectal, and pancreas cancer, respectively. After presenting survival probabilities by age at cohort entry and after adjusting for clinical characteristics, similar results were found with a few exceptions. Unlike the unadjusted analysis, in the adjusted analysis males with prostate cancer had a significantly higher survival compared with kidney transplant recipients and females with breast cancer had higher survival compared with kidney transplant recipients at 2+ years of follow-up. In a subpopulation of the cohort who had information available on cancer stage (ie, stages 1-4), we generally found similar results to our primary analysis with kidney transplant recipients having a higher survival probability compared with each cancer stage. However, female kidney transplant recipients had a lower survival probability compared with females with stage 1 breast cancer, whereas male kidney transplant recipients had a lower survival probability compared with males with stage 1 to 3 prostate cancer.

Limitations:

External generalizability, residual confounding, and cancer stage could only be provided for a subpopulation.

Conclusion:

Mortality in kidney transplant recipients is lower than in patients with several cancer types. These results improve our understanding of the mortality burden in this population and reaffirm kidney transplantation as a good treatment option for end-stage kidney disease but also highlight the continuing need to improve posttransplant survival.

Trial registration:

This is not applicable as this is a population-based cohort study and not a clinical trial.

National and international kidney failure registries: characteristics, commonalities, and contrasts

Registries are essential for health infrastructure planning, benchmarking, continuous quality improvement, hypothesis generation, and real-world trials. To date, data from these registries have predominantly been analyzed in isolated "silos," hampering efforts to analyze "big data" at the international level, an approach that provides wide-ranging benefits, including enhanced statistical power, an ability to conduct international comparisons, and greater capacity to study rare diseases. This review serves as a valuable resource to clinicians, researchers, and policymakers, by comprehensively describing kidney failure registries active in 2021, before proposing approaches for inter-registry research under current conditions, as well as solutions to enhance global capacity for data collaboration. We identified 79 kidney-failure registries spanning 77 countries worldwide. International Society of Nephrology exemplar initiatives, including the Global Kidney Health Atlas and Sharing Expertise to support the set-up of Renal Registries (SharE-RR), continue to raise awareness regarding international healthcare disparities and support the development of universal kidney-disease registries. Current barriers to inter-registry collaboration include underrepresentation of lower-income countries, poor syntactic and semantic interoperability, absence of clear consensus guidelines for healthcare data sharing, and limited researcher incentives. This review represents a call to action for international stakeholders to enact systemic change that will harmonize the current fragmented approaches to kidney-failure registry data collection and research.

Multicenter registry analysis comparing survival on home hemodialysis and kidney transplant recipients in Australia and New Zealand

BACKGROUND

In the era of organ shortage, home hemodialysis (HHD) has been identified as the possible preferential bridge to kidney transplantation. Data are conflicting regarding the comparability of HHD and transplantation outcomes. This study aimed to compare patient and treatment survival between HHD patients and kidney transplant recipients.

METHODS

The Australia and New Zealand Dialysis and Transplant Registry was used to include incident HHD patients on Day 90 after initiation of kidney replacement therapy and first kidney-only transplant recipients in Australia and New Zealand from 1997 to 2017. Survival times were analyzed using the Kaplan-Meier product-limit method comparing HHD patients with subtypes of kidney transplant recipients using the log-rank test. Adjusted analyses were performed with multivariable Cox proportional hazards regression models for time to all-cause mortality. Time-to-treatment failure or death was assessed as a composite secondary outcome.

RESULTS

The study compared 1411 HHD patients with 4960 living donor (LD) recipients, 6019 standard criteria donor (SCD) recipients and 2427 expanded criteria donor (ECD) recipients. While LD and SCD recipients had reduced risks of mortality compared with HHD patients [LD adjusted hazard ratio (HR) = 0.57, 95% confidence interval (CI) 0.46-0.71; SCD HR = 0.65 95% CI 0.52-0.79], the risk of mortality was comparable between ECD recipients and HHD patients (HR = 0.90, 95% CI 0.73-1.12). LD, SCD and ECD kidney recipients each experienced superior time-to-treatment failure or death compared with HHD patients.

CONCLUSIONS

This large registry study showed that kidney transplant offers a survival benefit compared with HHD but that this advantage is not significant for ECD recipients.

Survival and Lung Transplant Outcomes for Individuals With Advanced Cystic Fibrosis Lung Disease Living in the United States and Canada: An Analysis of National Registries

BACKGROUND

Understanding how health outcomes differ for patients with advanced cystic fibrosis (CF) lung disease living in the United States compared with Canada has health policy implications.

RESEARCH QUESTION

What are rates of lung transplant (LTx) and rates of death without LTx in the United States and Canada among individuals with FEV₁ < 40% predicted?

STUDY DESIGN AND METHODS

This was a retrospective population-based cohort study, 2005 to 2016, using the US CF Foundation, United Network for Organ Sharing, and Canadian CF registries. Individuals with CF and at least two FEV₁ measurements < 40% predicted within a 5-year period, age ≥ 6 years, without prior LTx were included. Multivariable competing risk regression for time to death without LTx (LTx as a competing risk) and time to LTx (death as a competing risk) was performed.

RESULTS

There were 5,899 patients (53% male) and 905 patients (54% male) with CF with FEV₁ < 40% predicted living in the United States and Canada, respectively. Multivariable competing risk regression models identified an increased risk of death without LTx (hazard ratio [HR], 1.79; 95% CI, 1.52-2.1) and decreased LTx (HR, 0.66; 95% CI, 0.58-0.74) among individuals in the United States compared with Canada. More pronounced differences were seen in the patients in the United States with Medicaid/Medicare insurance compared with Canadians (multivariable HR for death without LTx, 2.24 [95% CI, 1.89-2.64]; multivariable HR for LTx, 0.54 [95% CI, 0.47-0.61]). Patients of nonwhite race were also disadvantaged (multivariable HR for death without LTx, 1.56 [95% CI, 1.32-1.84]; multivariable HR for LTx, 0.47 [95% CI, 0.36-0.62]).

INTERPRETATION

There are lower rates of LTx and an increased risk of death without LTx for US patients with CF with FEV₁ < 40% predicted compared with Canadian patients. Findings are more striking among US patients with CF with Medicaid/Medicare health insurance, and nonwhite patients in both countries, raising concerns about underuse of LTx among vulnerable populations.

Survival comparisons in home hemodialysis: Understanding the present and looking to the future

A number of studies have compared relative survival for home hemodialysis patients (including longer hours/more frequent schedules) and other forms of renal replacement therapy. While informative, many of these studies have been limited by issues pertaining to their observational design including selection bias and residual confounding. Furthermore the few randomized controlled trials that have been conducted have been underpowered to detect a survival difference. Finally, in the face of a growing recognition of the value of patient-important outcomes beyond survival, the focus of comparisons between dialysis modalities may be changing. In this review, we will discuss the determinants of survival for patients receiving home hemodialysis and address the various studies that have compared relative survival for differing home hemodialysis schedules to each of in-center hemodialysis, peritoneal dialysis and transplantation. We will conclude this review by discussing whether there is an ongoing role for survival analyses in home hemodialysis.

Metabolic Consequences of Solid Organ Transplantation

Metabolic complications affect over 50% of solid organ transplant recipients. These include posttransplant diabetes, nonalcoholic fatty liver disease, dyslipidemia, and obesity. Preexisting metabolic disease is further exacerbated with immunosuppression and posttransplant weight gain. Patients transition from a state of cachexia induced by end-organ disease to a pro-anabolic state after transplant due to weight gain, sedentary lifestyle, and suboptimal dietary habits in the setting of immunosuppression. Specific immunosuppressants have different metabolic effects, although all the foundation/maintenance immunosuppressants (calcineurin inhibitors, mTOR inhibitors) increase the risk of metabolic disease. In this comprehensive review, we summarize the emerging knowledge of the molecular pathogenesis of these different metabolic complications, and the potential genetic contribution (recipient +/- donor) to these conditions. These metabolic complications impact both graft and patient survival, particularly increasing the risk of cardiovascular and cancer-associated mortality. The current evidence for prevention and therapeutic management of posttransplant metabolic conditions is provided while highlighting gaps for future avenues in translational research.

Bridging the survival gap in cystic fibrosis: An investigation of lung transplant outcomes in Canada and the United States

BACKGROUND

Previous literature in cystic fibrosis (CF) has shown a 10-year survival gap between Canada and the United States (US). We hypothesized that differential access to and survival after lung transplantation may contribute to the observed gap. The objectives of this study were to compare CF transplant outcomes between Canada and the US and estimate the potential contribution of transplantation to the survival gap.

METHODS

Data from the Canadian CF Registry and the US Cystic Fibrosis Foundation Patient Registry supplemented with data from United Network for Organ Sharing were used. The probability of surviving after transplantation between 2005 and 2016 was calculated using the Kaplan‒Meier method. Survival by insurance status at the time of transplantation and transplant center volume in the US were compared with those in Canada using Cox proportional hazard models. Simulations were used to estimate the contribution of transplantation to the survival gap.

RESULTS

Between 2005 and 2016, there were 2,653 patients in the US and 470 in Canada who underwent lung transplantation for CF. The 1-, 3-, and 5-year survival rates were 88.3%, 71.8%, and 60.3%, respectively, in the US compared with 90.5%, 79.9%, and 69.7%, respectively, in Canada. Patients in the US were also more likely to die on the waitlist (p < 0.01) than patients in Canada. If the proportion of who underwent transplantation and post-transplant survival in the US were to increase to those observed in Canada, we estimate that the survival gap would decrease from 10.8 years to 7.5 years.

CONCLUSIONS

Differences in waitlist mortality and post-transplant survival can explain up to a third of the survival gap observed between the US and Canada.

Frailty and the Kidney Transplant Wait List: Protocol for a Multicenter Prospective Study

Background:

Understanding how frailty affects patients listed for transplantation has been identified as a priority research need. Frailty may be associated with a high risk of death or wait-list withdrawal, but this has not been evaluated in a large multicenter cohort of Canadian wait-listed patients.

Objective:

The primary objective is to evaluate whether frailty is associated with death or permanent withdrawal from the transplant wait list. Secondary objectives include assessing whether frailty is associated with hospitalization, quality of life, and the probability of being accepted to the wait list.

Design:

Prospective cohort study.

Setting:

Seven sites with established renal transplant programs that evaluate patients for the kidney transplant wait list.

Patients:

Individuals who are being considered for the kidney transplant wait list.

Measurements:

We will assess frailty using the Fried Phenotype, a frailty index, the Short Physical Performance Battery, and the Clinical Frailty Scale at the time of listing for transplantation. We will also assess frailty at the time of referral to the wait list and annually after listing in a subgroup of patients.

Methods:

The primary outcome of the composite of time to death or permanent wait-list withdrawal will be compared between patients who are frail and those who are not frail and will account for the competing risks of deceased and live donor transplantation. Secondary outcomes will include number of hospitalizations and length of stay, and in a subset, changes in frailty severity over time, change in quality of life, and the probability of being listed. Recruitment of 1165 patients will provide >80% power to identify a relative hazard of ≥1.7 comparing patients who are frail to those who are not frail for the primary outcome (2-sided α = .05), whereas a more conservative recruitment target of 624 patients will provide >80% power to identify a relative hazard of ≥2.0.

Results:

Through December 2019, 665 assessments of frailty (inclusive of those for the primary outcome and all secondary outcomes including repeated measures) have been completed.

Limitations:

There may be variation across sites in the processes of referral and listing for transplantation that will require consideration in the analysis and results.

Conclusions:

This study will provide a detailed understanding of the association between frailty and outcomes for wait-listed patients. Understanding this association is necessary before routinely measuring frailty as part of the wait-list eligibility assessment and prior to ascertaining the need for interventions that may modify frailty.

Trial Registration:

Not applicable as this is a protocol for a prospective observational study.

Early and recurrent hospitalization after kidney transplantation: Analysis of a contemporary canadian cohort of kidney transplant recipients

Hospital readmission is a common occurrence following kidney transplantation, but less is known about the predictors of early and recurrent hospitalization. We analyzed a cohort of adult kidney transplant recipients in Nova Scotia, Canada, from January 2010 to December 2015. Readmission rates for 30 days, 6 months, and 1 year were calculated as a proportion of total transplants. Factors independently associated with early readmission were investigated using multivariable Cox hazards models with multivariable Anderson-Gill Cox models being used for factors independently associated with recurrent readmission. Of the 213 patients included, 41 (19.2%), 78 (36.6%), and 88 (41.3%) were readmitted to hospital within 30 days, 6 months, and 1 year, respectively. On multivariable analyses, a history of congestive heart failure (HR 1.741, 95% CI 1.039-2.918), peptic ulcer disease (HR 2.290, 95% CI 1.054-4.973), and liver disease (HR 2.492, 95% CI 1.162-5.344) was associated with higher risk of first rehospitalization. Recurrent hospital admission was associated with initial hospital duration ≥ 8 days (HR 2.140, 95% CI 1.265-3.618), congestive heart failure (HR 1.366, 95% CI 1.044-1.787), and liver disease (HR 1.785, 95% CI 1.257-2.534). Increasing duration of initial hospitalization, congestive heart failure, and liver disease are important to consider when evaluating a patient's risk for recurrent readmission following kidney transplant.

Use of the Living Kidney Donor Profile Index in the Canadian Kidney Transplant Recipient Population: A Validation Study

Background:

The Living Kidney Donor Profile Index (LKDPI) was derived in a cohort of kidney transplant recipients (KTR) from the United States to predict the risk of total graft failure. There are important differences in patient demographics, listing practices, access to transplantation, delivery of care, and posttransplant mortality in Canada as compared with the United States, and the generalizability of the LKDPI in the Canadian context is unknown.

Objective:

The purpose of this study was to externally validate the LKDPI in a large contemporary cohort of Canadian KTR.

Design:

Retrospective cohort validation study.

Setting:

Toronto General Hospital, University Health Network, Toronto, Ontario, Canada

Patients:

A total of 645 adult (≥18 years old) living donor KTR between January 1, 2006 and December 31, 2016 with follow-up until December 31, 2017 were included in the study.

Measurements:

The predictive performance of the LKDPI was evaluated. The outcome of interest was total graft failure, defined as the need for chronic dialysis, retransplantation, or death with graft function.

Methods:

The Cox proportional hazards model was used to examine the relation between the LKDPI and total graft failure. The Cox proportional hazards model was also used for external validation and performance assessment of the model. Discrimination and calibration were used to assess model performance. Discrimination was assessed using Harrell’s C statistic and calibration was assessed graphically, comparing observed versus predicted probabilities of total graft failure.

Results:

A total of 645 living donor KTR were included in the study. The median LKDPI score was 13 (interquartile range [IQR] = 1.1, 29.9). Higher LKDPI scores were associated with an increased risk of total graft failure (hazard ratio = 1.01; 95% confidence interval [CI] = 1.0-1.02; P = .02). Discrimination was poor (C statistic = 0.55; 95% CI = 0.48-0.61). Calibration was as good at 1-year posttransplant but suboptimal at 3- and 5-years posttransplant.

Limitations:

Limitations include a relatively small sample size, predicted probabilities for assessment of calibration only available for scores of 0 to 100, and some missing data handled by imputation.

Conclusions:

In this external validation study, the predictive ability of the LKDPI was modest in a cohort of Canadian KTR. Validation of prediction models is an important step to assess performance in external populations. Potential recalibration of the LKDPI may be useful prior to clinical use in external cohorts.

Care of acute conditions and chronic diseases in Canada and the United States: Rapid systematic review and meta-analysis

This study tested the hypothesis that socioeconomically vulnerable Canadians with diverse acute conditions or chronic diseases have health care access and survival advantages over their counterparts in the USA. A rapid systematic review retrieved 25 studies (34 independent cohorts) published between 2003 and 2018. They were synthesized with a streamlined meta-analysis. Very low-income Canadian patients were consistently and highly advantaged in terms of health care access and survival compared with their counterparts in the USA who lived in poverty and/or were uninsured or underinsured. In aggregate and controlling for specific conditions or diseases and typically 4 to 9 comorbid factors or biomarkers, Canadians' chances of receiving better health care were estimated to be 36% greater than their American counterparts (RR=1.36, 95% CI 1.35-1.37). This estimate was significantly larger than that based on general patient or non-vulnerable population comparisons (RR=1.09, 95% CI 1.08-1.10). Contrary to prevalent political rhetoric, three studies observed that Americans experience more than twice the risk of long waits for breast or colon cancer care or of dying while they wait for an organ transplant (RR=2.36, 95% CI 2.09-2.66). These findings were replicated across externally valid national studies and more internally valid, metropolitan or provincial/state comparisons. Socioeconomically vulnerable Canadians are consistently and highly advantaged on health care access and outcomes compared to their American counterparts. Less vulnerable comparisons found more modest Canadian advantages. The Affordable Care Act ought to be fully supported including the expansion of Medicaid across all states. Canada's single payer system ought to be maintained and strengthened, but not through privatization.

Black Ethnicity is Not a Risk Factor for Mortality or Graft Loss After Kidney Transplant in the United Kingdom

OBJECTIVES

There are conflicting reports in the literature regarding outcomes after kidney transplant for patients of black ethnicity. To investigate further, we compared outcomes for black versus white kidney transplant recipients in a single UK transplant center.

MATERIALS AND METHODS

We analyzed 1066 kidney transplant recipients (80 black patients, 986 white patients) within a single-center cohort (2007-2017) in the United Kingdom, with cumulative 4446 patient-year follow-up. Data were electronically extracted from the Department of Health Informatics database for every study recruit, with manual data linkage to the UK Transplant Registry (for graft survival, delayed graft function, and rejection data) and Office for National Statistics (for mortality data). Primary outcomes of interest were graft/patient survival.

RESULTS

Black recipients have increased baseline risk profiles with longer wait times, difficulty in matching, worse HLA matching, more socioeconomic deprivation, and lower rates of living kidney donors. Postoperatively, black versus white recipients had increased risk for delayed graft function (34.3% vs 10.2%; P < .001), increased 1-year rejection (16.7% vs 7.3%; P = .012), higher 1-year creatinine levels (166 vs 138 mmol/L; P = .003), and longer posttransplant length of stay (14.5 vs 9.5 days; P = .020). Although black recipients did not have increased risk of death versus white recipients (10.0% vs 11.0%, respectively; P = .486), they did have increased risk for death-censored graft loss (23.8% vs 11.1%; P = .002). However, in an adjusted Cox regression model, black ethnicity was not associated with increased risk for death-censored graft loss (hazard ratio of 1.209, 95% confidence interval, 0.660-2.216; P = .539).

CONCLUSIONS

Black kidney transplant recipients in the United Kingdom have increased risk of adverse graft-related outcomes due to high-risk baseline variables rather than their black ethnicity per se.

Kidney transplant graft outcomes in 379 257 recipients on 3 continents

Kidney transplant outcomes that vary by program or geopolitical unit may result from variability in practice patterns or health care delivery systems. In this collaborative study, we compared kidney graft outcomes among 4 countries (United States, United Kingdom, Australia, and New Zealand) on 3 continents. We analyzed transplant and follow-up registry data from 1988-2014 for 379 257 recipients of first kidney-only transplants using Cox regression. Compared to the United States, 1-year adjusted graft failure risk was significantly higher in the United Kingdom (hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.18-1.26, P < .001) and New Zealand (hazard ratio [HR] 1.29, 95% confidence interval [CI] 1.14-1.46, P < .001), but lower in Australia (HR 0.90, 95% CI 0.84-0.96, P = .001). In contrast, long-term adjusted graft failure risk (conditional on 1-year function) was significantly higher in the United States compared to Australia, New Zealand, and the United Kingdom (HR 0.74, 0.75, and 0.74, respectively; each P < .001). Thus long-term kidney graft outcomes are approximately 25% worse in the United States than in 3 other countries with well-developed kidney transplant systems. Case mix differences and residual confounding from unmeasured factors were found to be unlikely explanations. These findings suggest that identification of potentially modifiable country-specific differences in care delivery and/or practice patterns should be sought.

An Examination of the Application of the Kidney Donor Risk Index in British Columbia

Background:

The Kidney Donor Risk Index (KDRI) is a continuous measure of deceased donor kidney transplant failure risk that was derived in US patients based on 10 donor characteristics. In the United States, the KDRI is utilized to guide organ allocation and to inform clinical decisions regarding organ acceptance.

Objective:

To examine the application of the US-derived KDRI in a large Canadian province.

Patients:

All deceased donor kidney-only transplant recipients in British Columbia (BC) between 2005 and 2014.

Methods:

We examined the predictive performance of KDRI in BC transplant recipients and compared the overall performance of KDRI with donor age alone in predicting transplant failure (from all causes including death).

Results:

Donors in BC (N = 785) were older but included no black donors and few Hepatitis C virus (HCV)-positive donors compared with the original derivation cohort of the KDRI in the United States. The KDRI was moderately predictive of transplant failure (c statistic, 0.63) and had similar predictive performance to donor age alone (c statistic, 0.64).

Conclusion:

Our findings suggest that the US-derived KDRI does not improve the prediction of kidney transplant failure compared with donor age alone in a Canadian cohort and highlight the need to determine the applicability of KDRI in different regions.

Do outcomes after kidney transplantation differ for black patients in England versus New York State? A comparative, population-cohort analysis

OBJECTIVES

Inferior outcomes for black kidney transplant recipients in the USA may not be generalisable elsewhere. In this population cohort analysis, we compared outcomes for black kidney transplant patients in England versus New York State.

DESIGN

Retrospective, comparative, population cohort study utilising administrative data registries.

SETTINGS AND PARTICIPANTS

English data were derived from Hospital Episode Statistics, while New York State data were derived from Statewide Planning and Research Cooperative System. All adults receiving their first kidney-alone allograft between 2003 and 2013 were eligible for inclusion.

MEASURES

The primary outcome measure was mortality post kidney transplantation (including inhospital death, 30-day mortality and 1-year mortality). Secondary outcome measures included postoperative admission length of stay, risk of rehospitalisation, development of cardiac events, stroke, cancer or fracture and finally transplant rejection/failure. Cox proportional hazards regression was used to investigate relationship between ethnicity, country and outcome.

RESULTS

Black patients comprised 6.5% of the English cohort (n=1215/18 493) and 23.0% of the New York State cohort (n=2660/11 602). Compared with New York State, black kidney transplant recipients in England were more likely younger, male, living-donor kidney recipients and had dissimilar medical comorbidities. Inpatient mortality was not statistically different, but death within 30 days, 1 year or kidney transplant rejection/failure was lower among black patients in England versus black patients in New York State. In adjusted regression analysis, with black ethnicity the reference group, white patients had reduced risk for 30-day mortality (OR 0.62 (95% CI 0.44 to 0.86)) and 1-year mortality (OR 0.79 (95% CI 0.63 to 0.99)) in New York State but no difference was observed in England. Compared with England, black kidney transplant patients in New York State had increased HR for kidney transplant rejection rejection/failure by median follow-up (HR 2.15, 95% CI 1.91 to 2.43).

CONCLUSIONS

Outcomes after kidney transplantation for black patients may not be translatable between countries.

Racial Differences in Survival of Incident Home Hemodialysis and Kidney Transplant Patients

BACKGROUND

Previous studies have indicated that patients on maintenance hemodialysis have worse survival compared with kidney transplant (KTx) recipients. However, none of these studies have compared mortality of the US patients using alternative dialysis modalities such as home hemodialysis (HHD) with KTx recipients.

METHODS

Comparing patients who started HHD with those who received kidney transplantation in the United States between 2007 and 2011, we created a 1:1 propensity score-matched cohort of 4000 patients and examined the association between treatment modality and all-cause mortality using Cox proportional hazard models.

RESULTS

The mean ± SD age of the propensity score-matched HHD and KTx patients at baseline were 54 ± 15 years and 54 ± 14 years, 65% were men (both groups), 70% and 72% of patients were whites, and 19% were African American (both groups), respectively. Over 5 years of follow-up, HHD patients had 4 times higher mortality risk compared with KTx recipients in the entire patient population (hazard ratio [HR], 4.06; 95% confidence interval [95% CI], 3.27-5.04); total event number, 411), and similar difference was found across each race stratum. However, during the first year of therapy, although the white HHD patients had higher mortality risk (HR, 4.21; 95% CI, 3.10-5.73; total event number, 332) compared with their KTx counterparts, there was no significant difference in mortality risk between African American HHD and KTx patients (HR, 1.62; 95% CI, 0.77-3.39; total event number, 55). This result was consistent across different types of kidney donors.

CONCLUSIONS

The HHD patients appear to have 4 times higher mortality compared with KTx recipients regardless of the type of kidney donor. Further studies are needed to understand the reasons underlying racial differenes during the first year of therapy.

Current Status of Kidney Transplant Outcomes: Dying to Survive

Kidney transplantation is associated with improved survival compared with maintenance dialysis. In the United States, post-transplant outcomes have steadily improved over the last several decades, with current 1-year allograft and patient survival rates well over 90%. Although short-term outcomes are similar to those in the international community, long-term outcomes appear to be inferior to those reported by other countries. Differences in recipient case mix, allocation polices, and health care coverage contribute to the long-term outcome disparity. This review presents the current status of kidney transplant outcomes in the United States and compares them with the most recent outcomes from Australia and New Zealand, Europe, and Canada. In addition, early trends after implementation of the new kidney allocation system in the United States and its potential impact on post-transplant outcomes are discussed.

Utility of the Surgical Apgar Score in Kidney Transplantation: Is it Feasible to Predict ICU Admission, Hospital Readmission, Length of Stay, and Cost in This Patient Population?

BACKGROUND

This study analyzed the utility of the Surgical Apgar Scoring (SAS) system in predicting morbidity in kidney transplantation. Recipient comorbidities were evaluated for any effect on the SAS and then globally assessed for any relationship with intensive care unit (ICU) admission, need for dialysis, creatinine at discharge, length of stay, incremental, and total cost of transplantation. The hypothesis for this study is that a low SAS will be a statistically significant predictor of postoperative morbidity and associated costs.

METHODS

This was an institutional review board (IRB)-approved retrospective longitudinal cohort study on 204 solitary kidney transplant recipients (2009-2011). Patients were divided into 2 groups: low to moderate = SAS ≤ 7 and high = SAS ≥ 8. These groups were then analyzed against a host of variables.

RESULTS

Sixty-five percent of patients had an SAS of 7 or lower, while 35% had an SAS of 8 and higher. Recipients with a history of stroke were 88% more likely to be in the low-moderate SAS group (P = .017). Patients with lower SASs trended toward having less extended criteria donors (0.097) but were more likely to be admitted to the ICU (P = .043), leading to significantly higher transplant event hospitalization costs. Higher SASs were more likely to be readmitted to the hospital within 30 days of discharge (P = .027), leading to higher 30-day postdischarge costs (P = .014). Readmission rates, however, and 30-day follow-up costs were similar between SAS groups after controlling for donor characteristics, specifically donor marginality and recipient estimated glomerular filtration rate (eGFR).

CONCLUSION

The findings of this study suggest that a history of stroke in the recipient may lend to a lower SAS and that a low SAS is associated with ICU admission following transplant, leading to higher hospital costs.

Fracture Incidence in Adult Kidney Transplant Recipients

BACKGROUND

It remains uncertain whether kidney transplant recipients are a high-risk group for fracture.

METHODS

We conducted a cohort study using Ontario, Canada health care databases to estimate the 3-, 5- and 10-year cumulative incidence of nonvertebral fracture (proximal humerus, forearm, hip) in adult kidney transplant recipients between 1994 and 2009, stratifying by sex and age (<50 versus ≥50 years) at transplant. We also assessed the 3-year cumulative incidence of all fracture locations (excluding skull, toes, and fingers) and falls, 10-year cumulative incidence of hip fracture alone, and nonvertebral fracture incidence in recipients compared to nontransplant reference groups matched on age, sex, and cohort entry year. We studied 4821 recipients (median age, 50 years).

RESULTS

Among the age and sex strata, female recipients aged 50 years or older had the highest 3-year cumulative incidence of nonvertebral fracture (3.1%; 95% confidence interval [95% CI], 2.1-4.4%). Recipients had a higher 3-year cumulative incidence of nonvertebral fracture (1.6%; 95% CI, 1.3-2.0%) compared to the general population with no previous nonvertebral fracture (0.5%; 95% CI, 0.4-0.6%; P < 0.0001) and nondialysis chronic kidney disease (1.1%; 95% CI, 0.9-1.2%; P = 0.03), but a lower fracture incidence than the general population with a previous nonvertebral fracture (2.3%; 95% CI, 1.9-2.8%; P = 0.007). The 10-year cumulative incidence of hip fracture in all recipients was 1.7% (≥3% defined as high risk in clinical guidelines).

CONCLUSIONS

Kidney transplant recipients may have a lower fracture risk than previously suggested in the literature. Results inform our understanding of fracture incidence after kidney transplantation and how it compares to nontransplant populations.

The Canadian experience using the expanded criteria donor classification for allocating deceased donor kidneys for transplantation

Background

Although the outcomes of transplantation with expanded criteria donor (ECD) kidneys are inferior to non-ECD transplants in the USA, the impact of the ECD classification on Canadian kidney transplant recipients is not known.

Objectives

The objective of the study was to assess the performance of the US-derived ECD classification among deceased donor kidney transplant recipients in a Canadian setting.

Design

This study was a population-based cohort study.

Setting

The study was conducted in all adult kidney transplant centers in the province of Ontario.

Patients

The patients were incident-deceased donor kidney transplant recipients from January 1, 2005 to March 31, 2011.

Measurements

Study subjects were identified through the Trillium Gift of Life Network and linked to healthcare databases in Ontario. ECD status was based on age, hypertension, kidney function, and stroke-related death. Outcomes of interest included graft loss, death, and delayed graft function.

Methods

The Kaplan-Meier product limit method was used to graphically assess time to graft loss or death. Multivariable Cox proportional hazards models were used to assess graft loss or death as a function of ECD status. Multivariable logistic regression models were fitted for the outcome of delayed graft function.

Results

Of 1422 deceased donor kidney transplants, 325 (23 %) were from ECDs. The median donor age was 63 vs. 42 years for ECD vs. non-ECD, respectively. The 5-year cumulative incidence of total graft loss was 29.2 % in ECD and 20.7 % in non-ECD kidney transplants. The relative hazards for total graft loss (HR 1.48 [95 % CI, 1.10; 2.00]) and death-censored graft loss (HR 1.80 [95 % CI, 1.19, 2.71]) were increased in ECD vs. non-ECD transplants. Increased relative risks were also observed for death and delayed graft function, albeit not statistically significant.

Limitations

Although comprehensive in coverage and outcome ascertainment, the available details on covariate data may be limited in large healthcare databases.

Conclusions

The ECD classification identifies kidneys at increased risk for graft loss in Canadian patients. The performance of more granular measures of donor risk (e.g., Kidney Donor Risk Index) and its impact on organ allocation/utilization in Canadian patients requires further study.

Electronic supplementary material

The online version of this article (doi:10.1186/s40697-016-0106-9) contains supplementary material, which is available to authorized users.

Organ donation and transplantation in Canada: insights from the Canadian Organ Replacement Register

PURPOSE OF REVIEW

To provide an overview of the transplant component of the Canadian Organ Replacement Register (CORR).

FINDINGS

CORR is the national registry of organ failure in Canada. It has existed in some form since 1972 and currently houses data on patients with end-stage renal disease and solid organ transplants (kidney and/or non-kidney). The transplant component of CORR receives data on a voluntary basis from individual transplant centres and organ procurement organizations across the country. Coverage for transplant procedures is comprehensive and complete. Long-term outcomes are tracked based on follow-up reports from participating transplant centres. The longitudinal nature of CORR provides an opportunity to observe the trajectory of a patient's journey with organ failure over their life span. Research studies conducted using CORR data inform both practitioners and health policy makers alike.

IMPLICATIONS

The importance of registry data in monitoring and improving care for Canadian transplant candidates/recipients cannot be over-stated. This paper provides an overview of the transplant data in CORR including its history, data considerations, recent findings, new initiatives, and future directions.

Survival and hospitalization for intensive home hemodialysis compared with kidney transplantation

Canadian patients receiving intensive home hemodialysis (IHHD; ≥16 hours per week) have survival comparable to that of deceased donor kidney transplant recipients in the United States, but a comparison with Canadian kidney transplant recipients has not been conducted. We conducted a retrospective cohort study of consecutive, adult IHHD patients and kidney transplant recipients between 2000 and 2011 at a large Canadian tertiary care center. The primary outcome was time-to-treatment failure or death for IHHD patients compared with expanded criteria, standard criteria, and living donor recipients, and secondary outcomes included hospitalization rate. Treatment failure was defined as a permanent switch to an alternative dialysis modality for IHHD patients, and graft failure for transplant recipients. The cohort comprised 173 IHHD patients and 202 expanded criteria, 642 standard criteria, and 673 living donor recipients. There were 285 events in the primary analysis. Transplant recipients had a reduced risk of treatment failure/death compared with IHHD patients, with relative hazards of 0.45 (95% confidence interval [95% CI], 0.31 to 0.67) for living donor recipients, 0.39 (95% CI, 0.26 to 0.59) for standard criteria donor recipients, and 0.42 (95% CI, 0.26 to 0.67) for expanded criteria donor recipients. IHHD patients had a lower hospitalization rate in the first year of treatment compared with standard criteria donor recipients and in the first 3 months of treatment compared with living donor and expanded criteria donor recipients. In this cohort, kidney transplantation was associated with superior treatment and patient survival, but higher early rates of hospitalization, compared with IHHD.

Preoperative assessment of the deceased-donor kidney: from macroscopic appearance to molecular biomarkers

Variation in deceased-donor kidney quality can significantly affect outcomes after kidney transplantation. Suboptimal organ selection for a given recipient can result in primary nonfunction, premature graft failure, or inappropriate discard of a suitable organ. Appraisal and appropriate selection of deceased-donor kidneys for use in transplantation is therefore critical. A number of predictive tools have been developed to assist the transplant team in evaluating the suitability of a deceased-donor kidney for transplantation to a given recipient. These include stratification of donors into "standard-" or "expanded-criteria" categories based on clinical parameters, pre-implantation biopsy scores, donor risk scores, machine perfusion characteristics, functional kidney weight, donor biomarkers and molecular diagnostic tools, ex vivo viability assessment using postmortem normothermic perfusion, and overall macroscopic appraisal by the surgical team. Consensus as to the role and predictive value of each of these tools is lacking and clinical practice regarding evaluation and selection of kidneys varies considerably.In this review, we seek to critically appraise the literature and evaluate the levels of evidence for tools used to assess deceased-donor kidneys. Although a plethora of appraisal tools exist, very few demonstrate desirable predictive power to be useful in clinical decision-making. Further research using large, well-designed prospective studies is urgently needed to advance this important field of transplantation science.

Survival comparison between intensive hemodialysis and transplantation in the context of the existing literature surrounding nocturnal and short-daily hemodialysis

Our contemporary paradigms of nocturnal and short-daily hemodialysis (NHD and SDHD) have their origins in the earliest era of dialysis care for end-stage renal disease. However, these therapies have received considerably more attention in recent years owing to an increasing body of literature, suggesting a myriad of benefits attributable to these intensive dialysis regimens compared with conventional thrice-weekly hemodialysis. Analyses suggest a survival benefit for NHD and SDHD versus traditional hemodialysis prescriptions, and it is in this context that survival comparisons between intensive dialysis and transplantation must be considered. This literature and its limitations are reviewed here.

Risk factors for graft loss and mortality after renal transplantation according to recipient age: a prospective multicentre study

BACKGROUND

To describe the causes of graft loss, patient death and survival figures in kidney transplant patients in Spain based on the recipient's age.

METHODS

The results at 5 years of post-transplant cardiovascular disease (CVD) patients, taken from a database on CVD, were prospectively analysed, i.e. a total of 2600 transplanted patients during 2000-2002 in 14 Spanish renal transplant units, most of them receiving their organ from cadaver donors. Patients were grouped according to the recipient's age: Group A: <40 years, Group B: 40-60 years and Group C: >60 years. The most frequent immunosuppressive regimen included tacrolimus, mycophenolate mofetil and steroids.

RESULTS

Patients were distributed as follows: 25.85% in Group A (>40 years), 50.9% in Group B (40-60 years) and 23.19% in Group C (>60). The 5-year survival for the different age groups was 97.4, 90.8 and 77.7%, respectively. Death-censored graft survival was 88, 84.2 and 79.1%, respectively, and non death-censored graft survival was 82.1, 80.3 and 64.7%, respectively. Across all age groups, CVD and infections were the most frequent cause of death. The main causes of graft loss were chronic allograft dysfunction in patients <40 years old and death with functioning graft in the two remaining groups. In the multivariate analysis for graft survival, only elevated creatinine levels and proteinuria >1 g at 6 months post-transplantation were statistically significant in the three age groups. The patient survival multivariate analysis did not achieve a statistically significant common factor in the three age groups.

CONCLUSIONS

Five-year results show an excellent recipient survival and graft survival, especially in the youngest age group. Death with functioning graft is the leading cause of graft loss in patients >40 years. Early improvement of renal function and proteinuria together with strict control of cardiovascular risk factors are mandatory.

Comparison of the long-term outcomes of kidney transplantation: USA versus Spain

BACKGROUND

The long-term outcomes of kidney transplantation are suboptimal because many patients lose their allografts or experience premature death. Cross-country comparisons of long-term outcomes of kidney transplantation may provide insight into factors contributing to premature graft failure and death. We evaluated the rates of late graft failure and death among US and Spanish kidney recipients.

METHODS

This is a cohort study of US (n = 9609) and Spanish (n = 3808) patients who received a deceased donor kidney transplant in 1990, 1994, 1998 or 2002 and had a functioning allograft 1 year after transplantation with follow-up through September 2006. Ten-year overall and death-censored graft survival and 10-year overall recipient survival and death with graft function (DWGF) were estimated with multivariate Cox models.

RESULTS

Among recipients alive with graft function 1 year after transplant, the 10-year graft survival was 71.3% for Spanish and 53.4% for US recipients (P < 0.001). The 10-year, death-censored graft survival was 75.6 and 76.0% for Spanish and US recipients, respectively (P = 0.73). The 10-year recipient survival was 86.2% for Spanish and 67.4% for US recipients (P < 0.001). In recipients with diabetes as the cause of ESRD, the adjusted DWGF rates at 10 years were 23.9 and 53.8 per 1000 person-years for Spanish and US recipients, respectively (P < 0.001). Among recipients whose cause of ESRD was not diabetes mellitus, the adjusted 10-year DWGF rates were 11.0 and 25.4 per 1000 person-years for Spanish and US recipients, respectively.

CONCLUSIONS

US kidney transplant recipients had more than twice the long-term hazard of DWGF compared with Spanish kidney transplant recipients and similar levels of death-censored graft function. Pre-transplant medical care, comorbidities, such as cardiovascular disease, and their management in each country's health system are possible explanations for the differences between the two countries.

Pretransplant physical activity predicts all-cause mortality in kidney transplant recipients

BACKGROUND

Low physical activity (PA) has been associated with higher rates of cardiovascular disease (CVD) and mortality in the general population. Despite the benefits of kidney transplantation, kidney transplant recipients (KTRs) remain at elevated risk for CVD and mortality compared to individuals without kidney disease.

METHODS

A prospective cohort of 507 adult KTRs from three academic centers completed the Physical Activity Scale for the Elderly (PASE) at transplantation. PASE scores were divided into tertiles.

RESULTS

PA was lower with older age, history of CVD, smoking, and diabetes. During the median 8-year follow-up period, 128 individuals died, among whom 101 had a functioning allograft. In multivariable Cox regression for all-cause mortality, greater PA was strongly associated with better survival (HR: 0.52 for most active vs. inactive tertiles, 95% CI: 0.31-0.87, p = 0.01). Secondary analyses, in which (1) death with a functioning graft was the primary outcome, and (2) PASE scores were converted to the metabolic equivalent of task, revealed similar results. We did not find an association between change of PA after transplantation and mortality.

CONCLUSIONS

PA at the time of kidney transplantation is a strong predictor of all-cause mortality and death with graft function. Evaluation of PA level among kidney transplant candidates may be a useful method to risk-stratify patients for survival after kidney transplantation. Kidney transplant candidates and recipients should also be encouraged to be physically active.

Accepting kidneys from older living donors: impact on transplant recipient outcomes

Older living kidney donors are regularly accepted. Better knowledge of recipient outcomes is needed to inform this practice. This retrospective cohort study observed kidney allograft recipients from Ontario, Canada between January 2000 and March 2008. Donors to these recipients were older living (≥ 60 years), younger living, or standard criteria deceased (SCD). Review of medical records and electronic healthcare data were used to perform survival analysis. Recipients received 73 older living, 1187 younger living and 1400 SCD kidneys. Recipients of older living kidneys were older than recipients of younger living kidneys. Baseline glomerular filtration rate (eGFR) of older kidneys was 13 mL/min per 1.73 m² lower than younger kidneys. Median follow-up time was 4 years. The primary outcome of total graft loss was not significantly different between older and younger living kidney recipients [adjusted hazard ratio, HR (95%CI): 1.56 (0.98-2.49)]. This hazard ratio was not proportional and increased with time. Associations were not modified by recipient age or donor eGFR. There was no significant difference in total graft loss comparing older living to SCD kidney recipients [HR: 1.29 (0.80-2.08)]. In light of an observed trend towards potential differences beyond 4 years, uncertainty remains, and extended follow-up of this and other cohorts is warranted.

A validation study of the Canadian Organ Replacement Register

BACKGROUND AND OBJECTIVES

Accurate and complete documentation of patient characteristics and comorbidities in renal registers is essential to control bias in the comparison of outcomes across groups of patients or dialysis facilities. The objectives of this study were to assess the quality of data collected in the Canadian Organ Replacement Register (CORR) compared with the patient's medical charts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This cohort study of a representative sample of adult, incident patients registered in CORR in 2005 to 2006 examined the prevalence, sensitivity, specificity, positive and negative predictive values, and κ of comorbid conditions and agreement in coding of patient demographics and primary renal disease between CORR and the patient's medical record. The effect of coding variation on patient survival was evaluated.

RESULTS

Medical records on 1125 patients were reviewed. Agreement exceeded 97% for health card number, date of birth, and sex and 71% (range 46.6 to 89.1%) for the primary renal disease. Comorbid conditions were under-reported in CORR. Sensitivities ranged from 0.89 (95% confidence interval 0.80, 0.92) for hypertension to 0.47 (0.38, 0.55) for peripheral vascular disease. Specificity was >0.93 for all comorbidities except hypertension. Hazard ratios for death were similar whether calculated using data from CORR or the medical record.

CONCLUSIONS

Comorbid conditions are under-reported in CORR; however, the associated risks of mortality were similar whether using the CORR data or the medical record data, suggesting that CORR data can be used in clinical research with minimal concern for bias.

Low toxicity regimens in renal transplantation: a country subset analysis of the Symphony study

Regional transplant practices may affect clinical outcomes within multinational studies. This study evaluated whether the overall results from the Symphony study can be generalized to the participating countries. De novo adult renal transplant recipients (n = 1645) were randomized to receive standard-dose cyclosporine, or daclizumab induction plus low-dose cyclosporine, low-dose tacrolimus,or low-dose sirolimus, all in addition to mycophenolate mofetil and steroids. Data for the highest patient-recruiting countries, Spain (n = 275),Germany (n = 316) and Turkey (n = 258), were compared. Patient transplant characteristics were different among the country subsets; only deceased donors in Spain, more expanded criteria donors in Germany, and mainly living donors in Turkey. Efficacy results for the three countries were consistent with that of the overall study - renal function and biopsy-proven acute rejection (BPAR)rates were superior with low-dose tacrolimus. Turkey had higher mean calculated glomerular filtration rate across all treatment groups (60.6-72.2 ml/min)compared with that of Spain (51.1-57.5 ml/min) and Germany (51.3-62.9 ml/min). Spain and Turkey had lower BPAR rates across the four treatment groups compared with the overall study; Germany had much higher rates(21.0-54.2%). These findings confirm the general applicability of the Symphony study results and highlight the importance of inclusion of patients from different geographic origins in randomized clinical trials.

KDIGO clinical practice guideline for the care of kidney transplant recipients

The 2009 Kidney Disease: Improving Global Outcomes (KDIGO) clinical practice guideline on the monitoring, management, and treatment of kidney transplant recipients is intended to assist the practitioner caring for adults and children after kidney transplantation. The guideline development process followed an evidence-based approach, and management recommendations are based on systematic reviews of relevant treatment trials. Critical appraisal of the quality of the evidence and the strength of recommendations followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. The guideline makes recommendations for immunosuppression, graft monitoring, as well as prevention and treatment of infection, cardiovascular disease, malignancy, and other complications that are common in kidney transplant recipients, including hematological and bone disorders. Limitations of the evidence, especially on the lack of definitive clinical outcome trials, are discussed and suggestions are provided for future research.