Socioeconomic Status and Kidney Transplant Outcomes in a Universal Healthcare System: A Population-based Cohort Study

Distinct clinical profiles and post-transplant outcomes among kidney transplant recipients with lower education levels: uncovering patterns through machine learning clustering

BACKGROUND

Educational attainment significantly influences post-transplant outcomes in kidney transplant patients. However, research on specific attributes of lower-educated subgroups remains underexplored. This study utilized unsupervised machine learning to segment kidney transplant recipients based on education, further analyzing the relationship between these segments and post-transplant results.

METHODS

Using the OPTN/UNOS 2017-2019 data, consensus clustering was applied to 20,474 kidney transplant recipients, all below a college/university educational threshold. The analysis concentrated on recipient, donor, and transplant features, aiming to discern pivotal attributes for each cluster and compare post-transplant results.

RESULTS

Four distinct clusters emerged. Cluster 1 comprised younger, non-diabetic, first-time recipients from non-hypertensive younger donors. Cluster 2 predominantly included white patients receiving their first-time kidney transplant either preemptively or within three years, mainly from living donors. Cluster 3 included younger re-transplant recipients, marked by elevated PRA, fewer HLA mismatches. In contrast, Cluster 4 captured older, diabetic patients transplanted after prolonged dialysis duration, primarily from lower-grade donors. Interestingly, Cluster 2 showcased the most favorable post-transplant outcomes. Conversely, Clusters 1, 3, and 4 revealed heightened risks for graft failure and mortality in comparison.

CONCLUSIONS

Through unsupervised machine learning, this study proficiently categorized kidney recipients with lesser education into four distinct clusters. Notably, the standout performance of Cluster 2 provides invaluable insights, underscoring the necessity for adept risk assessment and tailored transplant strategies, potentially elevating care standards for this patient cohort.

Individual- and Community-Level Socioeconomic Status and Deceased Donor Renal Transplant Outcomes

BACKGROUND

This study examined the relationship between socioeconomic status (SES), race, and ethnicity and clinical outcomes following deceased donor kidney transplant (DDKT) at a high-volume transplant center.

METHODS

This retrospective cohort study used regression models and survival analyses to examine the relationship between individual- and community-level SES, race, and ethnicity and DDKT outcomes (i.e., delayed graft function, graft failure, mortality) adjusting for potential confounders.

RESULTS

The analytic sample included 3366 patients; 40.7% (n = 1370) were female, the mean age was 54.7 (SD = 13.3) years, 49.3% were non-Hispanic White, and the median follow-up time was 39.5 months (IQR = 24.2-68.1). Patients living in the most disadvantaged communities (using the US Census data) had a higher likelihood of delayed graft function (adjusted relative risk [RR] = 1.12, p = 0.042) and a higher hazard of mortality (adjusted hazard ratio [HR] = 1.32, p = 0.025) compared to patients living in the least disadvantaged communities. Patients without a high school diploma had a higher risk of delayed graft function compared to patients with an associate degree or more (RR = 1.37, p < 0.001). Patients with public insurance coverage had a higher risk of delayed graft function (RR = 1.24, p < 0.001) and a higher hazard of mortality (HR = 1.37, p < 0.001) and graft failure (HR = 1.71, p < 0.001) compared to patients without public insurance. There were no differences in graft failure or mortality by race and ethnicity.

CONCLUSIONS

SES was not consistently associated with outcomes following DDKT; however, many of the predictors were associated with delayed graft function. With a large and diverse sample size, these findings further the heterogeneity of the present renal transplant research suggesting the need for further investigation to guide implementation of innovative strategies and interventions.

Lifetime Risk of Hepatorenal Events Assessed in Longitudinal Cohort of Renal Transplant Recipients with HBV Infection

BACKGROUND

Kidney transplantation is a treatment option for patients with end-stage renal disease (ESRD) who are infected with hepatitis B virus (HBV). However, the impact of nucleos(t)ide analogues usage on the clinical outcomes in HBV-infected ESRD patients undergoing kidney transplantation is not well understood. This study aimed to assess the outcomes of kidney transplant recipients with HBV infection using real-world data to provide insight into the disease course over time.

METHODS

A nationwide retrospective longitudinal population-level cohort study was conducted using the National Health Insurance Research Database. The study evaluated patient and allograft survival and kidney-related and liver-related events and identified factors contributing to these events.

RESULTS

Of the 4838 renal transplant recipients in the study, there were no significant differences in graft survival between the HBV-infected and non-infected groups (P = .244). However, the HBV-infected group had suboptimal patient survival compared to the non-infected group (hazard ratio [HR] for overall survival, 1.80; 95% CI 1.40-2.30; P < .001). Diabetes mellitus was associated with a higher re-dialysis rate (HR, 1.71; 95% CI, 1.38-2.12; P < .001) regarding kidney-associated events. For liver-associated events, HBV-infected status (HR, 9.40; 95% CI, 5.66-15.63; P < .001), and age >60 years (HR, 6.90; 95% CI, 3.14-15.19; P < .001) were associated with increased incidence of liver cancer.

CONCLUSIONS

Hepatitis B-infected renal transplant recipients have comparable graft survival but inferior patient survival outcomes due to pre-existing diseases and increasing liver-related complications. The findings of this study can help optimize treatment strategies and improve long-term outcomes for this patient population.

Sociodemographic Variables in Canadian Organ Donation Organizations: A Health Information Survey

Health systems must collect equity-relevant sociodemographic variables to measure and mitigate health inequities. The specific variables collected by organ donation organizations (ODOs) across Canada, variable definitions, and processes of the collection are not defined. We undertook a national health information survey of all ODOs in Canada. These results will inform the development of a standard national dataset of equity-relevant sociodemographic variables.

Methods

We conducted an electronic, self-administered cross-sectional survey of all ODOs in Canada from November 2021 to January 2022. We targeted key knowledge holders familiar with the data collection processes within each Canadian ODO known to Canadian Blood Services. Categorical item responses are presented as numbers and proportions.

Results

We achieved a 100% response rate from 10 Canadian ODOs. Most data were collected by organ donation coordinators. Only 2 of 10 ODOs reported using scripts explaining why sociodemographic data are being collected or incorporated training in cultural sensitivity for any given variable. A lack of cultural sensitivity training was endorsed by 50% of respondents as a barrier to the collection of sociodemographic variables by ODOs, whereas 40% of respondents identified a lack of training in sociodemographic variable collection as a significant barrier.

Conclusions

Few programs routinely collect sufficient data to examine health inequities with an intersectional lens. Most data collection occurs midway through the ODO interaction, creating a missed opportunity to better understand differences in social identities of patients who register their intention to donate in advance or who decline the donation. National standardization of equity-relevant data collection definitions and processes of the collection is needed.

Telemedicine for Outpatient Care of Kidney Transplant and CKD Patients

INTRODUCTION

Telehealth videoconferencing (TVC) may improve access in rural areas, but reported uptake and outcomes among kidney transplant recipients (KTRs) and chronic kidney disease (CKD) patients are limited. This study aimed to assess the feasibility, sustainability, and clinical outcomes of TVC for this patient population.

METHODS

A total of 64 participants were recruited in this single-center, prospective, 2-year longitudinal, case-control study. Inclusion criteria for the telemedicine group included travel of ≥15 km to the hospital, and the control group was matched for transplant or CKD status, age, and sex. The primary outcome was feasibility (≥50% of consultations for each individual patient in the telemedicine group being conducted by TVC in year 1). Secondary outcomes were sustainability of telemedicine, change in blood pressure and creatinine, hospitalization, and travel distance.

RESULTS

There were 32 participants in both the telemedicine and control arms, with no baseline differences. The majority were male (65.6%) and the mean age was 63.9 years (SD = 12.3 years). TVC uptake in year 1 in the telemedicine arm was 71% (interquartile range [IQR] = 50.0-100.0) but reduced significantly in year 2 (50.0% [IQR = 33.3-71.4], P < 0.01). No significant differences in creatinine or blood pressure were observed between groups, including in the KTRs and CKD subgroup analysis. Patient satisfaction remained high for both groups. Compared with travel distance required if TVC was unavailable, travel distance in the TVC group decreased by 48% (16,644 km) in year 1 and by 37.0% (8177 km) in year 2.

CONCLUSION

TVC was feasible and sustainable, with outcomes comparable to those of standard care. Larger studies, especially among KTRs, are needed to confirm these findings.

Donor-derived Cell-free DNA: Advancing a Novel Assay to New Heights in Renal Transplantation

Despite advances in transplant immunosuppression, long-term renal allograft outcomes remain suboptimal because of the occurrence of rejection, recurrent disease, and interstitial fibrosis with tubular atrophy. This is largely due to limitations in our understanding of allogeneic processes coupled with inadequate surveillance strategies. The concept of donor-derived cell-free DNA as a signal of allograft stress has therefore rapidly been adopted as a noninvasive monitoring tool. Refining it for effective clinical use, however, remains an ongoing effort. Furthermore, its potential to unravel new insights in alloimmunity through novel molecular techniques is yet to be realized. This review herein summarizes current knowledge and active endeavors to optimize cell-free DNA-based diagnostic techniques for clinical use in kidney transplantation. In addition, the integration of DNA methylation and microRNA may unveil new epigenetic signatures of allograft health and is also explored in this report. Directing research initiatives toward these aspirations will not only improve diagnostic precision but may foster new paradigms in transplant immunobiology.

Economic Evaluation of Extending Medicare Immunosuppressive Drug Coverage for Kidney Transplant Recipients in the Current Era

BACKGROUND

Kidney transplant recipients must take immunosuppressant drugs to prevent rejection and maintain transplant function. Medicare coverage of immunosuppressant drugs for kidney transplant recipients ceases 36 months after transplantation, potentially increasing the risk of transplant failure. A contemporary economic analysis of extending Medicare coverage for the duration of transplant survival using current costs of immunosuppressant medications in the era of generic equivalents may inform immunosuppressant drug policy.

METHODS

A Markov model was used to determine the incremental cost and effectiveness of extending Medicare coverage for immunosuppressive drugs over the duration of transplant survival, compared with the current policy of 36-month coverage, from the perspective of the Medicare payer. The expected improvement in transplant survival by extending immunosuppressive drug coverage was estimated from a cohort of privately insured transplant recipients who receive lifelong immunosuppressant drug coverage compared with a cohort of Medicare-insured transplant recipients, using multivariable survival analysis.

RESULTS

Extension of immunosuppression Medicare coverage for kidney transplant recipients led to lower costs of -$3077 and 0.37 additional quality-adjusted life years (QALYs) per patient. When the improvement in transplant survival associated with extending immunosuppressant coverage was reduced to 50% of that observed in privately insured patients, the strategy of extending drug coverage had an incremental cost-utility ratio of $51,694 per QALY gained. In a threshold analysis, the extension of immunosuppression coverage was cost-effective at a willingness-to-pay threshold of $100,000, $50,000, and $0 per QALY if it results in a decrease in risk of transplant failure of 5.5%, 7.8%, and 13.3%, respectively.

CONCLUSIONS

Extending immunosuppressive drug coverage under Medicare from the current 36 months to the duration of transplant survival will result in better patient outcomes and cost-savings, and remains cost-effective if only a fraction of anticipated benefit is realized.