Quality Metrics in Kidney Transplantation: Current Landscape, Trials and Tribulations, Lessons Learned, and a Call for Reform

Defining pre-emptive living kidney donor transplantation as a quality indicator

Quality indicators in kidney transplants are needed to identify care gaps and improve access to transplants. We used linked administrative health care databases to examine multiple ways of defining pre-emptive living donor kidney transplants, including different patient cohorts and censoring definitions. We included adults from Ontario, Canada with advanced chronic kidney disease between January 1, 2013, to December 31, 2018. We created 4 unique incident patient cohorts, varying the eligibility by the risk of progression to kidney failure and whether individuals had a recorded contraindication to kidney transplant (eg, home oxygen use). We explored the effect of 4 censoring event definitions. Across the 4 cohorts, size varied substantially from 20 663 to 9598 patients, with the largest reduction (a 43% reduction) occurring when we excluded patients with ≥1 recorded contraindication to kidney transplantation. The incidence rate (per 100 person-years) of pre-emptive living donor kidney transplant varied across cohorts from 1.02 (95% CI: 0.91-1.14) for our most inclusive cohort to 2.21 (95% CI: 1.96-2.49) for the most restrictive cohort. Our methods can serve as a framework for developing other quality indicators in kidney transplantation and monitoring and improving access to pre-emptive living donor kidney transplants in health care systems.

Discrepant Outcomes between National Kidney Transplant Data Registries in the United States

SIGNIFICANCE STATEMENT

Effects of reduced access to external data by transplant registries to improve accuracy and completeness of the collected data are compounded by different data management processes at three US organizations that maintain kidney transplant-related datasets. This analysis suggests that the datasets have large differences in reported outcomes that vary across different subsets of patients. These differences, along with recent disclosure of previously missing outcomes data, raise important questions about completeness of the outcome measures. Differences in recorded deaths seem to be increasing in recent years, reflecting the adverse effects of restricted access to external data sources. Although these registries are invaluable sources for the transplant community, discrepancies and incomplete reporting risk undermining their value for future analyses, particularly when used for developing national transplant policy or regulatory measures.

BACKGROUND

Central to a transplant registry's quality are accuracy and completeness of the clinical information being captured, especially for important outcomes, such as graft failure or death. Effects of more limited access to external sources of death data for transplant registries are compounded by different data management processes at the United Network for Organ Sharing (UNOS), the Scientific Registry of Transplant Recipients (SRTR), and the United States Renal Data System (USRDS).

METHODS

This cross-sectional registry study examined differences in reported deaths among kidney transplant candidates and recipients of kidneys from deceased and living donors in 2000 through 2019 in three transplant datasets on the basis of data current as of 2020. We assessed annual death rates and survival estimates to visualize trends in reported deaths between sources.

RESULTS

The UNOS dataset included 77,605 deaths among 315,346 recipients and 61,249 deaths among 275,000 nonpreemptively waitlisted candidates who were never transplanted. The SRTR dataset included 87,149 deaths among 315,152 recipients and 60,042 deaths among 259,584 waitlisted candidates. The USRDS dataset included 89,515 deaths among 311,955 candidates and 63,577 deaths among 238,167 waitlisted candidates. Annual death rates among the prevalent transplant population show accumulating differences across datasets-2.31%, 4.00%, and 4.03% by 2019 from UNOS, SRTR, and USRDS, respectively. Long-term survival outcomes were similar among nonpreemptively waitlisted candidates but showed more than 10% discordance between USRDS and UNOS among transplanted patients.

CONCLUSIONS

Large differences in reported patient outcomes across datasets seem to be increasing, raising questions about their completeness. Understanding the differences between these datasets is essential for accurate, reliable interpretation of analyses that use these data for policy development, regulatory oversight, and research.

PODCAST

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Textbook Outcome as a Quality Metric in Living and Deceased Donor Kidney Transplantation

BACKGROUND

Quality in kidney transplantation is measured using 1-year patient and graft survival. Because 1-year patient and graft survival exceed 95%, this metric fails to measure a spectrum of quality. Textbook outcomes (TO) are a composite quality metric offering greater depth and resolution. We studied TO after living donor (LD) and deceased donor (DD) kidney transplantation.

STUDY DESIGN

United Network for Organ Sharing data for 69,165 transplant recipients between 2013 and 2017 were analyzed. TO was defined as patient and graft survival of 1 year or greater, 1-year glomerular filtration rate of greater than 40 mL/min, absence of delayed graft function, length of stay of 5 days or less, no readmissions during the first 6 months, and no episodes of rejection during the first year after transplantation. Bivariate analysis identified characteristics associated with TO, and covariates were incorporated into multivariable models. Five-year conditional survival was measured, and center TO rates were corrected for case complexity to allow center-level comparisons.

RESULTS

The national average TO rates were 54.1% and 31.7% for LD and DD transplant recipients. The hazard ratio for death at 5 years for recipients who did not experience TO was 1.92 (95% CI 1.68 to 2.18, p ≤ 0.0001) for LD transplant recipients and 2.08 (95% CI 1.93 to 2.24, p ≤ 0.0001) for DD transplant recipients. Center-level comparisons identify 18% and 24% of centers under-performing in LD and DD transplantation. High rates of TO do not correlate with transplantation center volume.

CONCLUSION

Kidney transplant recipients who experience TO have superior long-term survival. Textbook outcomes add value to the current standards of 1-year patient and graft survival.

A Population Health Approach to Transplant Access: Challenging the Status Quo

Transplant referral and evaluation are critical steps to waitlisting yet remain an elusive part of the transplant process. Despite calls for more data collection on pre-waitlisting steps, there are currently no national surveillance data to aid in understanding the causes and potential solutions for the extreme variation in access to transplantation. As population health scientists, epidemiologists, clinicians, and ethicists we submit that the transplant community has an obligation to better understand disparities in transplant access as a first necessary step to effectively mitigating these inequities. Our position is grounded in a population health approach, consistent with several new overarching national policy and quality initiatives. The purpose of this Perspective is to (1) provide an overview of how a population health approach should inform current multisystem policies impacting kidney transplantation and demonstrate how these efforts could be enhanced with national data collection on pre-waitlisting steps; (2) demonstrate the feasibility and concrete next steps for pre-waitlisting data collection; and (3) identify potential opportunities to use these data to implement effective population-level interventions, policies, and quality measures to improve equity in access to kidney transplantation.

Improving Clinical Governance of Kidney Transplantation: Review of a Ruling and of the Clinical Governance Process in the United Kingdom

The presentation of adverse events and negative outcomes is uncommon in scientific publications, particularly in a highly regulated and scrutinized practice such as solid organ transplantation. A ruling of a regulatory body of the pharmaceutical industry in the United Kingdom generates several considerations, in particular, regarding the governance process of kidney transplantation, as the events reported in the ruling are linked with high rejection rates and negative patient outcomes. This analysis offered a review of the current governance processes, while recognizing the relevant limitations of the system regulating kidney transplantation outcomes in the United Kingdom. The article identified some of the potential interventions that may contribute to delivering an improved governance, harmonizing contemporary practice, modern health care system, and establishing scientific knowledge.

Using Administrative Health Care Databases to Identify Patients With End-Stage Kidney Disease With No Recorded Contraindication to Receiving a Kidney Transplant

Background

Administrative health care databases can be efficiently analyzed to describe the degree to which patients with end-stage kidney disease (ESKD) have access to kidney transplantation. Measures of access to transplantation are better represented when restricting to only those patients eligible to receive a kidney transplant. The way administrative data can be used to assess kidney transplant eligibility in the absence of clinical data has not been well described.

Objective

To demonstrate a method that uses administrative health care databases to identify patients with ESKD who have no recorded contraindication to receiving a kidney transplant.

Design and setting

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

Patients

Adult patients with ESKD approaching the need for dialysis (predialysis) or receiving maintenance dialysis between January 1, 2013 and March 31, 2015 in Ontario, Canada.

Measurements

Recipient of a kidney-only or kidney-pancreas transplant.

Methods

We assessed more than 80 baseline characteristics, including demographic information, comorbidities, kidney-specific characteristics, and referral and listing criteria for kidney transplantation. We compared these characteristics between patients who did and did not receive a kidney transplant.

Results

We included 23 642 patients with ESKD (11 195 who were predialysis and 12 447 receiving maintenance dialysis). Over a median follow-up of 3.2 years (25th, 75th percentile: 1.3, 5.6), 3215 (13.6%) received a kidney-only or kidney-pancreas transplant. Of the studied characteristics available in administrative databases, >97% of patients with one or more of these characteristics did not receive a kidney transplant during follow-up: ESKD-modified Charlson Comorbidity Index score ≥7 (a higher score represents greater comorbidity), home oxygen use, age above 75 years, dementia, living in a long-term care facility, receiving at least one physician house call in the past year, and a combination of select malignancies (ie, lung, lymphoma, cervical, colorectal, liver, active multiple myeloma, and bladder cancer). Using these combined criteria reduced the total number of patients from 23 642 to 12 539 with no recorded contraindications to transplant (a 47% reduction), while the proportion who received a kidney transplant changed from 13.6% (denominator of 23 642) to 24.9% (denominator of 12 539).

Limitations

Administrative databases are unable to capture all the complexities of determining transplant eligibility.

Conclusion

We identified several criteria available within administrative health care databases that can be used to identify patients with ESKD who have no recorded contraindications to kidney transplant. These criteria could be applied when reporting measures of access to kidney transplantation that require knowledge of transplant eligibility.

Kidney Organ Allocation System: How to Be Fair

Transplantation is a life-saving medical intervention that unfortunately is constrained by scarcity of available organs. An ideal system for allocating organs should seek to achieve the greatest good for the greatest number of people. It also must be fair and not disadvantage certain populations. However, policies aimed at reducing disparities also must be balanced with considerations of utility (graft outcomes), cost, efficiency, and any adverse effects on organ utilization. Here, we discuss the ethical challenges of creating a fair and equitable organ allocation system, focusing on the principles governing deceased donor kidney transplant waitlists around the world. The kidney organ allocation systems in the United States, Australia, and Hong Kong are used as illustrations.

The Kidney Transplant Equity Index: Improving Racial and Ethnic Minority Access to Transplantation

OBJECTIVES

To develop a scalable metric which quantifies kidney transplant (KT) centers' performance providing equitable access to KT for minority patients, based on the individualized pre-listing prevalence of End-Stage Renal Disease (ESRD).

SUMMARY BACKGROUND DATA

Racial and ethnic disparities for access to transplant in patients with ESRD are well described; however, variation in care among KT centers remains unknown. Furthermore, no mechanism exists that quantifies how well a KT center provides equitable access to KT for minority patients with ESRD.

METHODS

From 2013-2018, custom datasets from the United States Renal Data System and United Network for Organ Sharing were merged to calculate the Kidney Transplant Equity Index (KTEI), defined as: the number of minority patients transplanted at a center relative to the prevalence of minority patients with ESRD in each center's health service area. Markers of socioeconomic status (SES) and recipient outcomes were compared between high and low KTEI centers.

RESULTS

249 transplant centers performed 111,959 KTs relative to 475,914 non-transplanted patients with ESRD. High KTEI centers performed more KTs for Black (105.5 vs. 24, P<0.001), Hispanic (55.5 vs. 7, P<0.001), and American Indian (1.0 vs. 0.0, P<0.001) patients than low KTEI centers. In addition, high KTEI centers transplanted more patients with higher unemployment (52 vs. 44, P<0.001), worse social deprivation (53 vs. 46, P<0.001), and lower educational attainment (52 vs. 43, P<0.001). While providing increased access to transplant for minority and low SES populations, high KTEI centers had improved patient survival (HR: 0.86, 95% CI: 0.77-0.95).

CONCLUSIONS

The KTEI is the first metric to quantify minority access to KT incorporating the pre-listing ESRD prevalence individualized to transplant centers. KTEIs uncover significant national variation in transplant practices and identify highly equitable centers. This novel metric should be used to disseminate best practices for minority and low socioeconomic patients with ESRD.

The role of bypass filters in deceased donor kidney allocation in the United States

Kidney transplant centers set organ offer filters enabling all candidates at their center to be bypassed during allocation of deceased donor kidneys from the UNOS Organ Center. These filters aim to increase allocation efficiency by preemptively screening out offers unlikely to be accepted. National data were used to compare filter settings of 175 centers in 2007 and in 2019. We examined characteristics of centers whose settings became increasingly restrictive over time, and associations between filter settings and organ offer acceptance. Overall, centers became more open to receiving offers over time, from a median 62% of filters open to receiving national offers in 2007 to 73% in 2019. Intravenous drug use filter settings changed most, from 63 to 153 willing centers. Centers with more open filter settings had higher transplant volume and offer acceptance ratios across all risk categories despite preemptively screening out fewer offers compared to centers with less open settings, but similar transplant rates. There was significant geographic heterogeneity in the distribution of centers with more open filter settings. Current center bypass filters may impact patients' access to transplantation without achieving their full potential for improving allocation efficiency.

Textbook Outcome as a Quality Metric in Liver Transplantation

Quality in liver transplantation (LT) is currently measured using 1-y patient and graft survival. Because patient and graft survival rates now exceed 90%, more informative metrics are needed. Textbook outcomes (TOs) describe ideal patient outcomes after surgery. This study critically evaluates TO as a quality metric in LT.

Keys to Driving Implementation of the New Kidney Care Models

Contemporary nephrology practice is heavily weighted toward in-center hemodialysis, reflective of decisions on infrastructure and personnel in response to decades of policy. The Advancing American Kidney Health initiative seeks to transform care for patients and providers. Under the initiative’s framework, the Center for Medicare and Medicaid Innovation has launched two new care models that align patient choice with provider incentives. The mandatory ESRD Treatment Choices model requires participation by all nephrology practices in designated Hospital Referral Regions, randomly selecting 30% of all Hospital Referral Regions across the United States for participation, with the remaining Hospital Referral Regions serving as controls. The voluntary Kidney Care Choices model offers alternative payment programs open to nephrology practices throughout the country. To help organize implementation of the models, we developed Driver Diagrams that serve as blueprints to identify structures, processes, and norms, and generate intervention concepts. We focused on two goals that are directly applicable to nephrology practices and central to the incentive structure of the ESRD Treatment Choices and Kidney Care Choices: (1) increasing utilization of home dialysis, and (2) increasing the number of kidney transplants. Several recurring themes became apparent with implementation. Multiple stakeholders from assorted backgrounds are needed. Communication with primary care providers will facilitate timely referrals, education, and comanagement. Nephrology providers (nephrologists, nursing, dialysis organizations, others) must lead implementation. Patient engagement at nearly every step will help achieve the aims of the models. Advocacy with federal and state regulatory agencies will be crucial to expanding home dialysis and transplantation access. Although the models hold promise to improve choices and outcomes for many patients, we must be vigilant that they not do reinforce existing disparities in health care or widen known racial, socioeconomic, or geographic gaps. The Advancing American Kidney Health initiative has the potential to usher in a new era of value-based care for nephrology.

Managing Patients with Failing Kidney Allograft: Many Questions Remain

Patients who receive a kidney transplant commonly experience failure of their allograft. Transplant failure often comes with complex management decisions, such as when and how to wean immunosuppression and start the transition to a second transplant or to dialysis. These decisions are made in the context of important concerns about competing risks, including sensitization and infection. Unfortunately, the management of the failed allograft is, at present, guided by relatively poor-quality data and, as a result, practice patterns are variable and suboptimal given that patients with failed allografts experience excess morbidity and mortality compared with their transplant-naive counterparts. In this review, we summarize the management strategies through the often-precarious transition from transplant to dialysis, highlighting the paucity of data and the critical gaps in our knowledge that are necessary to inform the optimal care of the patient with a failing kidney transplant.

Failure to Advance Access to Kidney Transplantation over Two Decades in the United States

BACKGROUND

Extensive research and policies have been developed to improve access to kidney transplantation among patients with ESKD. Despite this, wide variation in transplant referral rates exists between dialysis facilities.

METHODS

To evaluate the longitudinal pattern of access to kidney transplantation over the past two decades, we conducted a retrospective cohort study of adult patients with ESKD initiating ESKD or placed on a transplant waiting list from 1997 to 2016 in the United States Renal Data System. We used cumulative incidence models accounting for competing risks and multivariable Cox models to evaluate time to waiting list placement or transplantation (WLT) from ESKD onset.

RESULTS

Among the study population of 1,309,998 adult patients, cumulative 4-year WLT was 29.7%, which was unchanged over five eras. Preemptive WLT (prior to dialysis) increased by era (5.2% in 1997-2000 to 9.8% in 2013-2016), as did 4-year WLT incidence among patients aged 60-70 (13.4% in 1997-2000 to 19.8% in 2013-2016). Four-year WLT incidence diminished among patients aged 18-39 (55.8%-48.8%). Incidence of WLT was substantially lower among patients in lower-income communities, with no improvement over time. Likelihood of WLT after dialysis significantly declined over time (adjusted hazard ratio, 0.80; 95% confidence interval, 0.79 to 0.82) in 2013-2016 relative to 1997-2000.

CONCLUSIONS

Despite wide recognition, policy reforms, and extensive research, rates of WLT following ESKD onset did not seem to improve in more than two decades and were consistently reduced among vulnerable populations. Improving access to transplantation may require more substantial interventions.

Kidney transplant program waitlisting rate as a metric to assess transplant access

Kidney transplant program performance in the United States is commonly measured by posttransplant outcomes. Inclusion of pretransplant measures could provide a more comprehensive assessment of transplant program performance and necessary information for patient decision-making. In this study, we propose a new metric, the waitlisting rate, defined as the ratio of patients who are waitlisted in a center relative to the person-years referred for evaluation to a program. Furthermore, we standardize the waitlisting rate relative to the state average in Georgia, North Carolina, and South Carolina. The new metric was used as a proof-of-concept to assess transplant-program access compared to the existing transplant rate metric. The study cohorts were defined by linking 2017 United States Renal Data System (USRDS) data with transplant-program referral data from the Southeastern United States between January 1, 2012 and December 31, 2016. Waitlisting rate varied across the 9 Southeastern transplant programs, ranging from 10 to 22 events per 100 patient-years, whereas the program-specific waitlisting rate ratio ranged between 0.76 and 1.33. Program-specific waitlisting rate ratio was uncorrelated with the transplant rate ratio (r = -.15, 95% CI, -0.83 to 0.57). Findings warrant collection of national data on early transplant steps, such as referral, for a more comprehensive assessment of transplant program performance and pretransplant access.

Financial impact of delayed graft function in kidney transplantation

Increased utilization of suboptimal organs in response to organ shortage has resulted in increased incidence of delayed graft function (DGF) after transplantation. Although presumed increased costs associated with DGF are a deterrent to the utilization of these organs, the financial burden of DGF has not been established. We used the Premier Healthcare Database to conduct a retrospective analysis of healthcare resource utilization and costs in kidney transplant patients (n = 12 097) between 1/1/2014 and 12/31/2018. We compared cost and hospital resource utilization for transplants in high-volume (n = 8715) vs low-volume hospitals (n = 3382), DGF (n = 3087) vs non-DGF (n = 9010), and recipients receiving 1 dialysis (n = 1485) vs multiple dialysis (n = 1602). High-volume hospitals costs were lower than low-volume hospitals ($103 946 vs $123 571, P < .0001). DGF was associated with approximately $18 000 (10%) increase in mean costs ($130 492 vs $112 598, P < .0001), 6 additional days of hospitalization (14.7 vs 8.7, P < .0001), and 2 additional ICU days (4.3 vs 2.1, P < .0001). Multiple dialysis sessions were associated with an additional $10 000 compared to those with only 1. In conclusion, DGF is associated with increased costs and length of stay for index kidney transplant hospitalizations and payment schemes taking this into account may reduce clinicians' reluctance to utilize less-than-ideal kidneys.

An opt-out model for kidney transplant referral: The time has come

Disparities that affect equity in access to kidney transplantation for patients with kidney failure have been well described. Many robust clinical trials have tested the effectiveness of interventions to reduce disparities and equilibrate access to kidney transplantation. Moreover, policy changes have been enacted to achieve the same aims. Despite these efforts, rates of kidney transplant waitlisting within the first year of end-stage kidney disease have remained unchanged over the past 2 decades, while incident rates of end-stage kidney disease have climbed. Because prior interventions have not durably increased transplant access, disruptive change is clearly needed. The Advancing American Kidney Health Executive Order sets bold goals to transform kidney care for patients and caregivers. In this spirit, we discuss an Opt-Out for Transplant Referral Model as a compelling solution to improve equity in access to kidney transplantation.

An international comparison of deceased donor kidney utilization: What can the United States and the United Kingdom learn from each other?

In transplant, meaningful international comparisons in organ utilization are needed. This collaborative study between the United Kingdom (UK) and the United States (US) aimed to develop a kidney utilization metric allowing for legitimate intercountry comparisons. Data from the UK and US transplant registries, including all deceased donor kidneys recovered from 2006 to 2017, were analyzed. To identify a potentially comparable kidney utilization rate (UR), several denominators were assessed. We discovered that the proportion of transplanted kidneys from elderly donors in the UK (10.7%) was 18 times greater than that in the US (0.6%). Conversely, en bloc pediatric kidney transplant was more common in the US. Donation after circulatory death utilization has risen in both countries but is twice as prevalent in the UK (39% of transplants) vs the US (20%). In addition, US and UK URs are not directly comparable due to fundamental system differences. However, using a suite of URs revealed practice areas likely to yield the most benefit if improved, such as efforts to increase kidney offer acceptance in the US and to reduce postacceptance discard in the UK. Methods used in this study, including novel intracountry risk-adjusted UR trend logistic regression analyses, can be translated to other international transplant registries in pursuit of further global learning opportunities.

Policies to promote timely referral for kidney transplantation

There are numerous patient, provider, and health system barriers to accessing kidney transplantation. Patient barriers such as sociocultural and clinical characteristics and provider factors such as provider knowledge and awareness of transplantation play important roles in facilitating transplant. Health system factors like misaligned incentives and quality metrics for dialysis facilities and transplant centers also influence transplant access. While numerous studies have documented the impact of these barriers on wait-listing and transplant, few studies have examined referral from a dialysis facility to a transplant center and start of the transplant evaluation process. While the Centers for Medicare and Medicaid Services (CMS) require that dialysis facilities educate patients about transplant, there are no guidelines for the content and objectives for this education. In addition, policies to require timely referral for transplantation have been considered by CMS but are difficult to implement without national data on referral. Federal policies should be amended to mandate transplant center submission of referral data-while decreasing the unfunded mandate to collect other unusable data currently collected as part of regulatory monitoring of transplant centers-to promote timely access to transplant, increased transplant rates, and to better understand the multilevel barriers and facilitators to transplant referral.