Individual and regional factors of access to the renal transplant waiting list in france in a cohort of dialyzed patients

Twenty years of the French Renal Epidemiology and Information Network

Background

The French Renal Epidemiology and Information Network (REIN) is 20 years old. It is not just a national data registry, but rather an epidemiological and informational network serving patients with chronic kidney disease, nephrology teams and health services.

Methods

The past 10-year trends of the incidence and prevalence of renal replacement therapy by dialysis or kidney transplantation and waitlist activity are presented. To detect potential significant changes in trends from 2012 and 2021, a Joinpoint regression model was used.

Results

The overall incidence of treated end-stage kidney disease (ESKD) was 169 per million population (pmp) in 2021. It was stable despite an increase in the incidence of diabetes. We found a decreasing trend in the proportion of patients starting dialysis in an emergency but an increase in those starting haemodialysis (HD) with a temporary catheter. Peritoneal dialysis decreased by 1.7% each year, whereas home HD, although involving only 1% of dialysis patients, increased by 10% each year. For patients not treated at home, the median time to drive from the patient's home to the dialysis unit was 17 min. The proportion of patients on the transplantation waitlist at the start of dialysis increased from 7% to 12%. Among the 111 263 new ESKD patients from 2012 to 2021, 8% received a first transplant at 1 year and 20% at 5 years. Among kidney transplant recipients, the mean time on the waitlist increased from 13.8 to 22.6 months. Living donor transplants increased in frequency, representing 15% of kidney transplants.

Conclusions

Data from the REIN registry allow for the evaluation of needs and provide a planning tool for French authorities. The progressive implementation of automatic data retrieval from dialysis informatics charts might alleviate the burden of data collection. Furthermore, the research activity the REIN engenders, resulting in renewed confidence by health authorities in the dynamism of French nephrology, allows for an optimistic outlook for the REIN.

[REIN: a tool for the benefit of renal transplantation]

On the occasion of the 20th anniversary of the REIN (French Renal Epidemiology and Information Network), a summary work on the contributions of the national French ESKD register was carried out. On the issue of access to renal transplantation for ESKD patients, the following key messages were retained. The registry of the REIN includes data about kidney transplant and dialysis. It thus allows evaluating the access to kidney transplant in France based on the needs of the population with stage 5 CKD treated by renal replacement therapy. The data produced by the registry is complementary to the data in the report of the Agence de la biomédecine (Agency of Biomedicine) based on the activity of the transplant centres and the population of registered patients waiting for a transplant. The proportion of preemptive transplant (transplant without prior recourse to dialysis) as well as that of preemptive registration (before starting dialysis) have increased since 2012 but remain low. The proportion of preemptive transplant as the first replacement therapy remains low and stable over time at around 3 to 4%. The access to the waiting list and the transplant varies depending on the age and co-morbidities of the patients (diabetes, obesity) as well as on the region. The rates of registration on the kidney transplant waiting list at the time of initiation of dialysis and at 1 year from the start have been increasing since 2012, irrespective of the patients’ characteristics, though it remains low in elderly, diabetic and severely obese patients. This is partly the result related to the publication of the HAS (French National Authority for Health) recommendations in 2015 and the publications on the disparities in access to transplants established thanks to the REIN registry. The causes of non-registration at the time of initiation of dialysis have changed over time with some patients not registering for contraindication steadily decreasing since 2012. Thanks to several studies conducted using data from the registry, the variations in access to the list could be explained, partly, by the health condition of the dialysis population as well as by the socio-economic context and differences in practices according to dialysis networks. The median waiting time for a kidney transplant has been gradually increasing since 2012, with a delta of about 8 months between 2012 and 2020. However, the waiting time between the initiation of dialysis and the transplant has increased less significantly. The probability of receiving a first kidney transplant depends on the age, diabetic status and obesity of the patient, and has remained stable over time.

Survival Benefit of Kidney Transplantation in Patients With End-Stage Kidney Disease and Prior Acute Myocardial Infarction

Patients with end stage kidney disease (ESKD) and a previous acute myocardial infarction (AMI) have less access to KT. Data on ESKD patients with an AMI history who underwent first KT or dialysis between January 2007 and December 2018 were extracted from the Korean National Health Insurance Service. Patients who underwent KT (n = 423) were chronologically matched in a 1:3 ratio with those maintained on dialysis (n = 1,269) at the corresponding dates, based on time-conditional propensity scores. The 1, 5, and 10 years cumulative incidences for all-cause mortality were 12.6%, 39.1%, and 60.1% in the dialysis group and 3.1%, 7.2%, and 14.5% in the KT group. Adjusted hazard ratios (HRs) of KT versus dialysis were 0.17 (95% confidence interval [CI], 0.12-0.24; p < 0.001) for mortality and 0.38 (95% CI, 0.23-0.51; p < 0.001) for major adverse cardiovascular events (MACE). Of the MACE components, KT was most protective against cardiovascular death (HR, 0.23; 95% CI, 0.12-0.42; p < 0.001). Protective effects of KT for all-cause mortality and MACE were consistent across various subgroups, including patients at higher risk (e.g., age >65 years, recent AMI [<6 months], congestive heart failure). KT is associated with lower all-cause mortality and MACE than maintenance dialysis patients with a prior AMI.

Perception of social inequities in the access to the kidney transplant waiting list by nephrology trainees: a national survey

BACKGROUND

Social inequalities in health are responsible for disparities in access to the kidney transplant waiting list (KTWL). The perception of disparities by nephrologists has consequences for the registration on the KTWL. The purposes of our study were to assess the perception of the factors implicated in the disparities in access to the KTWL by nephrology trainees and to assess the quality of the questionnaire.

METHODS

A questionnaire was developed to assess the perception of the determinants of the inequities in access to waitlisting. Continuous variables were described by median, 1st and 3rd quartiles. Categorical variables were described by frequencies and percentages. A principal component analysis and a hierarchical cluster analysis were performed to approach the correlation between the variables. A scree plot and a factor analysis were performed to determine the dimensions of the questionnaire. The internal consistency was estimated by Cronbach's coefficient.

RESULTS

The response rate was 98/110 (89%). The determinants of inequities in the access to KTWL not perceived by the nephrology trainees were "female sex", "income level" and "the centre provision to adapt the information to all of the patients" (18,3%, 36,7, 47% respectively). "Age", "being born abroad", "place of living", "education level", "transplant centre", "the health care provider" were determinants of disparities perceived by most of the trainees (85,7%, 75,5%, 82,6%, 78,6%, 73,5% et 78,5% respectively). Items related to the transplant centre were positively correlated, as well as "being born abroad", "education level" and "income level". The Cronbach's coefficient was 0,60.

CONCLUSION

Social inequalities in health are partially perceived by nephrology trainees. A teaching session could raise nephrologists' awareness of this issue and could help reduce the impact of these disparities on the course of ESKD (end-stage kidney disease) patients.

[Access to the kidney transplantation waiting list for peritoneal dialysis patients in New-Caledonia and Wallis and Futuna]

INTRODUCTION

Since 2012, a deceased donor kidney transplant program exists for dialysis patients living in New-Caledonia in collaboration with Royal Prince Alfred Hospital in Sydney, Australia. This program has reduced the time spent out-of-territory for a renal transplantation and has reduced the economic burden of end stage renal disease in New-Caledonia. We have realised a photography of kidney transplants evaluation for patients in peritoneal dialysis in New-Caledonia and Wallis and Futuna. The first aim was to describe access to kidney transplants evaluation for dialysis patients. A second aim was to compare patients with a conformed kidney transplant evaluation and patients without transplant evaluation with no obvious reasons identified.

METHOD

All patients in peritoneal dialysis in New-Caledonia and Wallis and Futuna at the 2018, 31st july were included. A standardised form was filled by two nephrologists. The computerised shared medical record was used to collect information. A kidney transplant evaluation was adequate for patients registered on transplant waiting list, patients with medical contraindications identified or patients with evaluation exams begun less than 6 months.

RESULTS

In total, 61 patients were included. The average age was 62 years old. The chronic kidney disease care average time was 6.7 years and the dialysis average time was 2.0 years. Among them, 11 (18 %) were registered on the waiting list, 26 (43 %) had at least one kidney transplant medical contraindication, 3 (5 %) had begun transplant exam since less than 6 months and 21 (34 %) had no transplant exam begun or transplant exam begun since more than 6 months without medical contraindication identified. Among those 21 patients, the three most common reasons were a faulty programming transplant exam (67 %; n = 14), a remote living place (48 %; n = 10) and an intercurrent health event (29 %; n = 6). Among patients living in Noumea and suburbs, 74 % had a conformed transplant evaluation against 44 % in patients living outside Noumea and suburbs (P = 0.058). Nearly one in two patients not on the waiting list had have no information about kidney graft or the information was not recorded in the medical record.

CONCLUSION

This study showed two main factors of a non-conformed transplantation evaluation: living outside Noumea and suburbs and a non-efficient planning of pre-transplant assessment exams. There is also a lack of information to the patient. These risk factors for late registration and non-registration must be considered by the healthcare teams. This study will provide a point of reference to assess the impact of actions to improve access to renal transplantation deployed in New-Caledonia.

Women's Access to Kidney Transplantation in France: A Mixed Methods Research Protocol

Kidney transplantation is the best renal replacement therapy (medically and economically) for eligible patients with end-stage kidney disease. Studies in some French regions and in other countries suggest a lower access to the kidney transplant waiting listing and also to kidney transplantation, once waitlisted, for women. Using a mixed methods approach, this study aims to precisely understand these potential sex disparities and their causes. The quantitative study will explore the geographic disparities, compare the determinants of access to the waiting list and to kidney transplantation, and compare the reasons and duration of inactive status on the waiting list in women and men at different scales (national, regional, departmental, and census-block). The qualitative study will allow describing and comparing women's and men's views about their disease and transplantation, as well as nephrologists' practices relative to the French national guidelines on waiting list registration. This type of study is important in the current societal context in which the reduction of sex/gender-based inequalities is a major social expectation.

Sex Differences in Kidney Transplantation: Austria and the United States, 1978–2018

Background

Systematic analyses about sex differences in wait-listing and kidney transplantation after dialysis initiation are scarce. We aimed at identifying sex-specific disparities along the path of kidney disease treatment, comparing two countries with distinctive health care systems, the US and Austria, over time.

Methods

We analyzed subjects who initiated dialysis from 1979–2018, in observational cohort studies from the US and Austria. We used Cox regression to model male-to-female cause-specific hazard ratios (csHRs, 95% confidence intervals) for transitions along the consecutive states dialysis initiation, wait-listing, kidney transplantation and death, adjusted for age and stratified by country and decade of dialysis initiation.

Results

Among 3,053,206 US and 36,608 Austrian patients starting dialysis, men had higher chances to enter the wait-list, which however decreased over time [male-to-female csHRs for wait-listing, 1978–1987: US 1.94 (1.71, 2.20), AUT 1.61 (1.20, 2.17); 2008–2018: US 1.35 (1.32, 1.38), AUT 1.11 (0.94, 1.32)]. Once wait-listed, the advantage of the men became smaller, but persisted in the US [male-to-female csHR for transplantation after wait-listing, 2008–2018: 1.08 (1.05, 1.11)]. The greatest disparity between men and women occurred in older age groups in both countries [male-to-female csHR for wait-listing after dialysis, adjusted to 75% age quantile, 2008–2018: US 1.83 (1.74, 1.92), AUT 1.48 (1.02, 2.13)]. Male-to-female csHRs for death were close to one, but higher after transplantation than after dialysis.

Conclusions

We found evidence for sex disparities in both countries. Historically, men in the US and Austria had 90%, respectively, 60% higher chances of being wait-listed for kidney transplantation, although these gaps decreased over time. Efforts should be continued to render kidney transplantation equally accessible for both sexes, especially for older women.

Frailty among chronic kidney disease patients on the kidney transplant waiting list: the sex–frailty paradox

Background

Frailty is defined as decreased physiologic reserve and resistance to stressors that predisposes patients towards poor health results. Its prevalence in chronic kidney disease (CKD) patients who are kidney transplant (KT) candidates is high. Frailty is associated with a higher rate of complications and mortality after transplant. It is unknown whether frailty phenotype differs depending on sex in this population.

Methods

This was a prospective longitudinal study of 455 KT candidates evaluated for frailty by physical frailty phenotype at the time of inclusion on the KT waiting list. Pre-frailty was defined as the presence of two criteria and frailty as three or more criteria. Univariate and multivariate analyses searched for associations of frailty status, frailty components and gender differences.

Results

Thirty percent of the total cohort resulted to be pre-frail (20%) or frail (10.3%), but disparities were observed between sexes, with 22.5% of men and 47.2% of women falling into one of these categories. Among frailty criteria, women presented with a higher percentage of exhaustion (39.6% versus 17%) and slowness (22.2% versus 9.6%) compared with men. Comorbidity burden was higher among frail men, whereas social factors were poorer between frail women. Disability was common among those patients who were frail, both men and women.

Conclusions

Frailty is twice as frequent in advanced CKD women as men. Frailty criteria distribution and phenotype seem to differ among sexes, which might have implications in terms of specific and individualized interventions to improve their status before transplantation.

Effect of age and care organization on sources of variation in kidney transplant waiting list registration

Despite national guidelines, medical practices and kidney transplant waiting list registration policies may differ from one dialysis/transplant unit to another. Benefit risk assessment variations, especially for elderly patients, have also been described. The aim of this study was to identify sources of variation in early kidney transplant waiting list registration in France. Among 16 842 incident patients during the period 2016-2017, 4386 were registered on the kidney transplant waiting list at the start of, or during the first year after starting, dialysis (26%). We developed various log-linear mixed effect regression models on three levels: patients, dialysis networks, and transplant centers. Variability was expressed as variance from the random intercepts (± standard error). Although patient characteristics have an important impact on the likelihood of registration, the overall magnitude of variability in registration was low and shared by dialysis networks and transplant centers. Between-transplant center variability (0.23 ± 0.08) was 1.8 higher than between-dialysis network variability (0.13 ± 0.004). Older age was associated with a lower probability of registration and greater variability between networks (0.04, 0.20, & 0.93 in the 18-64, 65-74, and 75-84 age groups). Targeted interventions should focus on elderly patients and/or certain regions with greater variability in waiting list access.

Significance of HLA-DQ in kidney transplantation: time to reevaluate human leukocyte antigen matching priorities to improve transplant outcomes? An expert review and recommendations

The weight of human leukocyte antigen (HLA) matching in kidney allocation algorithms, especially in the United States, has been devalued in a stepwise manner, supported by the introduction of modern immunosuppression. The intent was further to reduce the observed ethnic/racial disparity, as data emerged associating HLA matching with decreased access to transplantation for African American patients. In recent years, it has been increasingly recognized that a leading cause of graft loss is chronic antibody-mediated rejection, attributed to the development of de novo antibodies against mismatched donor HLA expressed on the graft. These antibodies are most frequently against donor HLA-DQ molecules. Beyond their impact on graft survival, generation of de novo donor-specific HLA antibodies also leads to increased sensitization, as measured by panel-reactive antibody metrics. Consequently, access to transplantation for patients returning to the waitlist in need of a second transplant is compromised. Herein, we address the implications of reduced HLA matching policies in kidney allocation. We highlight the observed diminished outcome data, the significant financial burden, the long-term health consequences, and, more important, the unintended consequences. We further provide recommendations to examine the impact of donor-recipient HLA class II and specifically HLA-DQα₁β₁ mismatching, focusing on collection of appropriate data, application of creative simulation approaches, and reconsideration of best practices to reduce inequalities while optimizing patient outcomes.

Day-Time Declamping Is Associated with Better Outcomes in Kidney Transplantation: The Circarein Study

Despite improvements in organ preservation techniques and efforts to minimize the duration of cold ischemia, ischemia–reperfusion (IR) injury remains associated with poor graft function and long-term survival in kidney transplantation. We recently demonstrated a clinically significant day-time variation in myocardial tolerance to IR, transcriptionally orchestrated by the circadian clock. Patient and graft post-transplant survival were studied in a cohort of 10,291 patients first transplanted between 2006 and 2017 to test whether kidney graft tolerance to IR depends on the time-of-the-day of clamping/declamping, and thus impacts graft and patient survival. Post-transplant 1- and 3-year survival decreased with increasing ischemia duration. Time-of-the-day of clamping did not influence outcomes. However, night-time (vs. day-time) declamping was associated with a significantly worse post-transplant survival. After adjustment for other predictors, night-time (vs. day-time) declamping remained associated with a worse 1-year (HR = 1.26 (1.08–1.47), p = 0.0028 by Cox multivariable analysis) and 3-year (HR = 1.14 (1.02–1.27), p = 0.021) outcome. Interestingly, the deleterious impact of prolonged ischemia time (>15 h) was partially compensated by day-time (vs. night-time) declamping. Compared to night-time declamping, day-time declamping was associated with a better prognosis of kidney transplantation despite a longer duration of cold ischemia.

[Frailty in chronic kidney disease]

The prevalence of frailty is very high in patients with chronic renal insufficiency and increases with its severity. A number of factors associated with chronic renal insufficiency appear to favor the frequent occurrence of frailty in these patients. In addition to its unfavorable impact on the quality of life, morbidity and mortality, frailty is an important criterion in setting treatment goals for chronic kidney disease as well as in the decision whether to undergo dialysis treatment or conservative treatment without dialysis and also in listing a patient for a kidney transplantation. There is still uncertainty about the measures to improve the effects of frailty in patients with chronic kidney insufficiency. These can vary considerably depending on the stage and course of the kidney disease and external circumstances. Individual physical, psychological or emotional problems can be identified on the basis of a geriatric assessment including a social anamnesis. This forms the foundation for tailored measures, such as advice on how to behave when suffering from kidney disease, training therapy and rehabilitation. Patients with renal insufficiency seem to benefit from the latter to a similar extent as patients without kidney disease. Thus, an early assessment of frailty-associated problems in patients with chronic renal insufficiency could help to identify deficits as soon as possible and, by measures adapted to the situation, to achieve an improvement in the quality of life and/or prognosis of these patients.

Factors Affecting Access to the Kidney Transplant Waiting List in Eastern Hungary

Kidney transplantation is the best available treatment choice for patients suffering from end-stage renal disease; however, not all patients with end-stage renal disease have equal access to it. The aim of the study was to measure the factors that may influence access to the kidney transplant waiting list in eastern Hungary. A total of 254 patients with renal failure between 18 and 75 years old from 8 dialysis centers participated in the study. The factors associated with access to the waiting list were identified by univariate descriptive analysis and multivariate logistic regression analysis where the outcome variable was placement on the kidney transplant waiting list. Our findings demonstrates that patients registered on the waiting list were younger (odds ratio [OR] = 0.96; 95% confidence interval [CI], 0.94-0.98), were male (OR = 0.54; 95% CI, 0.30-0.98), were economically active (OR = 0.53; 95% CI, 0.29-0.98), and had greater knowledge in the field (OR = 1.17; 95% CI, 1.03-1.33). Disparity in access to the kidney transplant waiting list in Hungary does exist.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Practice patterns of dialysis access and outcomes in patients wait-listed early for kidney transplantation

BACKGROUND

Early kidney transplantation (KT) is the best option for patients with end-stage kidney disease, but little is known about dialysis access strategy in this context. We studied practice patterns of dialysis access and how they relate with outcomes in adults wait-listed early for KT according to the intended donor source.

METHODS

This study from the REIN registry (2002-2014) included 9331 incident dialysis patients (age 18-69) wait-listed for KT before or by 6 months after starting dialysis: 8342 candidates for deceased-donor KT and 989 for living-donor KT. Subdistribution hazard ratios (SHR) of KT and death associated with hemodialysis by catheter or peritoneal dialysis compared with arteriovenous (AV) access were estimated with Fine and Gray models.

RESULTS

Living-donor candidates used pretransplant peritoneal dialysis at rates similar to deceased-donor KT candidates, but had significantly more frequent catheter than AV access for hemodialysis (adjusted OR 1.25; 95%CI 1.09-1.43). Over a median follow-up of 43 (IQR: 23-67) months, 6063 patients received transplants and 305 died before KT. Median duration of pretransplant dialysis was 15 (7-27) months for deceased-donor recipients and 9 (5-15) for living-donor recipients. Catheter use in deceased-donor candidates was associated with a lower SHR for KT (0.88, 95%CI 0.82-0.94) and a higher SHR for death (1.53, 95%CI 1.14-2.04). Only five deaths occurred in living-donor candidates, three of them with catheter use.

CONCLUSIONS

Pretransplant dialysis duration may be quite long even when planned with a living donor. Advantages from protecting these patients from AV fistula creation must be carefully evaluated against catheter-related risks.

Living or deceased-donor kidney transplant: the role of psycho-socioeconomic factors and outcomes associated with each type of transplant

BACKGROUND

Kidney transplant improves patients' survival and quality of life. Worldwide, concern about the equality of access to the renal transplant wait-list is increasing. In Iran, patients have the choice to be placed on either the living or deceased-donor transplant wait-list.

METHODS

This was a prospective study performed on 416 kidney transplant recipients (n = 217 (52.2%) from living donors and n = 199 (47.8%) from deceased donors). Subjects were recruited from four referral kidney transplant centers across Tehran, Iran, during 2016-2017. The primary outcome was to identify the psycho-socioeconomic factors influencing the selection of type of donor (living versus deceased). Secondary objective was to compare the outcomes associated with each type of transplant. The impact of psycho-socioeconomic variables on selecting type of donor was evaluated by using multiple logistic regression and the effect of surgical and non-surgical variables on the early post-transplant creatinine trend was assessed by univariate repeated measure ANOVA.

RESULTS

Based on standardized coefficients, the main predictors for selecting living donor were academic educational level (adjusted OR = 3.25, 95% CI: 1.176-9.005, p = 0.023), psychological status based on general health questionnaire (GHQ) (adjusted OR = 2.46, 95% CI: 1.105-5.489, p = 0.028), and lower monthly income (adjusted OR = 2.20, 95% CI: 1.242-3.916, p = 0.007). The waiting time was substantially shorter in patients who received kidneys from living donors (p < 0.001). The early post-transplant creatinine trend was more desirable in recipients of living donors (β = 0.80, 95% CI: 0.16-1.44, p-value = 0.014), patients with an ICU stay of fewer than five days (β = - 0.583, 95% CI: - 0.643- -0.522, p-value = < 0.001), and those with less dialysis duration time (β = 0.016, 95% CI: 0.004-0.028, p-value = 0.012). Post-operative surgical outcomes were not different across the two groups of recipients (p = 0.08), however, medical complications occurred considerably less in the living-donor group (p = 0.04).

CONCLUSION

Kidney transplant from living donors was associated with shorter transplant wait-list period and better early outcome, however, inequality of access to living donors was observed. Patients with higher socioeconomic status and higher level of education and those suffering from anxiety and sleep disorders were significantly more likely to select living donors.

Sex Differences in Kidney Replacement Therapy Initiation and Maintenance

BACKGROUND AND OBJECTIVES

More men than women undergo kidney replacement therapy (KRT) despite a larger number of women being affected by CKD. The aim of this multinational European study was to explore whether there might be historic and geographic trends in sex-specific incidence and prevalence of various KRT modalities.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We assessed sex-specific differences in KRT incidence and prevalence using data from nine countries reporting to the European Renal Association-European Dialysis and Transplant Association (ERA-EDTA) Registry for at least 40 years, during the period 1965-2015. Sex distribution data were compared with the European general population (Eurostat). Statistical methodology included basic descriptive statistics, incidence and prevalence calculations per million population (pmp), as well as their male-to-female ratios. Analyses were stratified by age group and diabetic status.

RESULTS

We analyzed data from 230,378 patients receiving KRT (38% women). For all KRT modalities, the incidence and prevalence rates were consistently higher in men than women. For example, the KRT incidence increased from 8 pmp in 1965-1974 to 98 pmp in 2005-2015 in women, whereas it rose from 12 to 173 pmp in men during the same period. Male-to-female ratios, calculated for incident and prevalent KRT patients, increased with age (range 1.2-2.4), showing consistency over decades and for individual countries, despite marked changes in primary kidney disease (diabetes more prevalent than glomerulonephritis in recent decades). The proportion of kidney transplants decreased less with age in incident and prevalent men compared with women on KRT. Stratified analysis of patients who were diabetic versus nondiabetic revealed that the male-to-female ratio was markedly higher for kidney transplantation in patients with diabetes.

CONCLUSIONS

Since the beginning of KRT programs reporting to the ERA-EDTA Registry since the 1960s, fewer women than men have received KRT. The relative difference between men and women initiating and undergoing KRT has remained consistent over the last five decades and in all studied countries.

Maximising access to kidney transplantation: A single-centre audit of people receiving dialysis

BACKGROUND

Despite transplantation being well documented as the renal replacement therapy option that gives the best morbidity and mortality outcomes, the best quality of life and the best value for healthcare dollar, not all patients are on a kidney transplant waiting list.

OBJECTIVES

The aims of this study were (1) to explore possible reasons for a demonstrated a higher rate of people being listed as suitable for transplant in a non-transplanting unit and (2) to describe a formal process of review and referral as a method for maximising the number of people gaining access to the transplant waiting list.

METHODS

We prospectively audited all patients who were undergoing dialysis in our metropolitan, non-transplanting renal unit annually over six years to determine whether not being on the transplant waiting list was in keeping with available eligibility guidelines of medical and behavioural criteria.

RESULTS

In every age group, the percentage of patients listed for transplant was higher than that seen in national data. The most common reasons for people not to be listed were malignancy, obesity and cardiovascular disease. This unit's patients had fewer smokers, less females and less Aboriginal and Torres Strait Islanders which may have contributed towards a higher rate of activation on the list.

CONCLUSION

In this dialysis patient population having a formal process of review for suitability and referral, as well as a specialist renal transplant coordinator nurse positively affected the number of patients being activated on the transplant waiting list.

Daily hemodialysis practices in Australia/New Zealand and in France: a comparative cohort study

Background

As patients on daily hemodialysis (DHD) have heterogeneous profiles, DHD benefit in terms of survival is still debated. The aim of this study was to compare DHD practices in France and in Australia and New Zealand.

Methods

This study was based on data from the French Renal Epidemiology and Information Network (REIN) and the Australian and New Zealand Dialysis and Transplant Registry (ANZDATA). All incident patients from both registries who underwent DHD (i.e., 5–6 sessions/week, including short daily hemodialysis and long nocturnal hemodialysis) at least once during their trajectories were included, and their characteristics and care trajectories were compared. For survival analyses, one French patient was matched to one Australian or New Zealand patient, based on age, sex and year of dialysis start. Survival was assessed using the Cox proportional hazards model, and access to renal transplantation was evaluated using the Fine & Gray model to take into account death as competing risk.

Results

Between 2003 and 2012, 523 patients from the AZNDATA and 753 from the REIN registry started DHD. ANZDATA patients were younger (54.8 vs 64.0 years, p < 0.001) and had comorbidities more frequently than French patients. In both registries, one third of patients were on early DHD (i.e., DHD started less than one year after dialysis initiation). Long nocturnal hemodialysis was more frequent in the ANZDATA than in the REIN cohort (20.8 and 3%, respectively). Comparison of the matched subgroups showed comparable survival rates between French and Australian/New Zealand patients (HRadjusted = 1.08; 95%CI: 0.78–1.50). Access to renal transplantation also was similar between matched groups (SHRadjusted = 1.30, 95%CI: 0.86–1.97).

Conclusions

Our study shows that, despite differences in terms of patients’ characteristics and DHD regimens, the mortality risk and access to renal transplantation are similar in France and Australia and New Zealand.

Electronic supplementary material

The online version of this article (10.1186/s12882-019-1330-1) contains supplementary material, which is available to authorized users.

[What do registries compared to clinical trials tell us?]

The objective of this review is to illustrate the interests of registries in terms of clinical research, using practical examples from the French REIN registry. In addition to their interest in terms of observation and decision-making for public health, registries may also be used to compare structures, and to evaluate causality in clinical research. Indeed, even though randomized controlled trials are the gold standard to assess causality, they may be difficult to perform, with an applicability in daily life that remains to be demonstrated since patients are highly selected patients with a very close follow-up. In contrast, observational studies from registries have other advantages, and notably high number of patients, low cost, relatively rapid research, focus on specific sub-groups. In the future, data mining with an implementation of a huge number of data for patients (hospitalization data, genetics, ambulatory care, etc.) will dramatically improve the databases. We may even imagine running RCTs directly in registries, with lower costs and patients closer to reality. However, many challenges remain to be solved, and notably the ethical issues of confidentiality and protection of patients in these "mega-databases". Cet article fait partie du numéro supplément Innovations en Néphrologie réalisé avec le soutien institutionnel de Vifor Fresenius Medical Care Renal Pharma.

Mortality and Kidney Transplantation Outcomes Among Hepatitis C Virus-Seropositive Maintenance Dialysis Patients: A Retrospective Cohort Study

RATIONALE & OBJECTIVE

Hepatitis C virus (HCV) infection is common among maintenance dialysis patients. Few studies have examined both dialysis survival and transplantation outcomes for HCV-seropositive patients because registry data sets lack information for HCV serostatus.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

Adult long-term dialysis patients treated by a US national dialysis provider between January 1, 2004, and December 31, 2014.

EXPOSURE

HCV antibody serostatus obtained as part of clinical data from a national dialysis provider.

OUTCOMES

Mortality on dialysis therapy, entry onto the kidney transplant waiting list, kidney transplantation, and estimated survival benefit from kidney transplantation versus remaining on the waitlist.

ANALYTICAL APPROACH

After linking clinical data with data from the Organ Procurement and Transplantation Network, Cox and cause-specific hazards regression were implemented to estimate the associations between HCV seropositivity and mortality, as well as entry onto the kidney transplant waitlist. Cox regression was also used to estimate the survival benefit from transplantation versus dialysis among HCV-seropositive individuals.

RESULTS

Among 442,171 dialysis patients, 31,624 (7.2%) were HCV seropositive. HCV seropositivity was associated with a small elevation in the rate of death (adjusted HR [aHR], 1.09; 95% CI, 1.07-1.11) and a substantially lower rate of entry onto the kidney transplant waitlist (subdistribution HR [sHR], 0.67; 95% CI, 0.61-0.74). Once wait-listed, the kidney transplantation rate was not different for HCV-seropositive (sHR 1.10; 95% CI, 0.96-1.27) versus HCV-seronegative patients. HCV-seropositive patients lived longer with transplantation (aHR at 3 years, 0.42; 95% CI, 0.27-0.63). Receiving an HCV-seropositive donor kidney provided a survival advantage at the 2-year posttransplantation time point compared to remaining on dialysis therapy waiting for an HCV-negative kidney.

LIMITATIONS

No data for HCV viral load or liver biopsy.

CONCLUSIONS

HCV-seropositive patients experience reduced access to the kidney transplantation waitlist despite deriving a substantial survival benefit from transplantation. HCV-seropositive patients should consider foregoing HCV treatment while accepting kidneys from HCV-infected donors to facilitate transplantation and prolong survival.

Categorical state sequence analysis and regression tree to identify determinants of care trajectory in chronic disease: Example of end-stage renal disease

BACKGROUND

Patients with chronic diseases, like patients with end-stage renal disease (ESRD), have long history of care driven by multiple determinants (medical, social, economic, etc.). Although in most epidemiological studies, analyses of health care determinants are computed on single health care events using classical multivariate statistical regression methods. Only few studies have integrated the concept of treatment trajectories as a whole and studied their determinants.

METHODS

All 18- to 80-year-old incident ESRD patients who started dialysis in Ile-de-France or Bretagne between 2006 and 2009 and could be followed for a period of 48 months after initiation of a renal replacement therapy were included (n = 5568). Their care trajectories were defined as categorical state sequences. Associations between patients' characteristics and care trajectories were assessed using a regression tree model together with a discrepancy analysis.

RESULTS

On average, each patient experienced 1.56 different renal replacement therapies (min = 1; max = 5) during the 48 months of follow-up. About 55% of patients never changed treatment and only 1% tried three or more renal replacement therapy modalities. Twelve homogeneous care trajectory groups were identified. Covariates explained 12% of the discrepancy between groups, particularly age, regions and initiation of hemodialysis with a catheter.

CONCLUSIONS

Regression tree analysis of categorical state sequence highlighted geographical disparities in the care trajectory of French patients with ESRD that cannot be observed when focusing on a single outcome, such as survival. This method is an original tool to visualize and characterize care trajectories, notably in the context of chronic condition like ESRD.

County socioeconomic characteristics and heart transplant outcomes in the United States

BACKGROUND

Geographic disparities in survival after heart transplantation have received mixed support in prior studies, and specific geographic characteristics that might be responsible for these differences are unclear. We tested for differences in heart transplant outcomes across United States (US) counties after adjustment for individual-level covariates. Our secondary aim was to evaluate whether specific county-level socioeconomic characteristics explained geographic disparities in survival.

METHODS

Data on patients aged ≥18 years undergoing a first-time heart transplant between July 2006 and December 2014 were obtained from the United Network for Organ Sharing. Residents of counties represented by <5 patients were excluded. Patient survival (censored in March 2016) was analyzed using multivariable Cox regression. Shared frailty models were used to test for residual differences in overall all-cause mortality across counties after adjusting for recipient and donor characteristics. Measures of county economic disadvantage, inequality, and racial segregation were obtained from US Census data and coded into quintiles. A likelihood ratio test determined whether adjusting for each county measure improved the fit of the Cox model.

RESULTS

Multivariable analysis of 10,879 heart transplant recipients found that, adjusting for individual-level characteristics, there remained statistically significant variation in mortality hazard across US counties (P=.004). Adjusting for quintiles of community disadvantage, economic inequality, or racial segregation did not significantly improve model fit (likelihood ratio test P=.092, P=.273, and P=.107, respectively) and did not explain residual differences in patient survival across counties.

CONCLUSIONS

Heart transplantation outcomes vary by county, but this difference is not attributable to county-level socioeconomic disadvantage.

Factors affecting willingness to receive a kidney transplant among hemodialysis patients in West China: A cross-sectional survey

Many factors are associated with the willingness of ESRD patients to receive a kidney transplant. No data are available for patients in China. The study aim was to describe the attitudes toward transplantation in a cohort of patients at a single dialysis center in China.A study questionnaire derived from previously published literature was completed by 239 hemodialysis outpatients. Factors associated with willingness to receive a transplant were identified by univariate and multivariate logistic regression analyses.The respondents were primarily men 50.7 ± 15.1 years of age; 46.4% were willing to receive a transplant. Younger age (OR = 0.928, 95% CI: 0.898-0.959), good self-reported health (OR = 0.203, 95% CI: 0.081-0.51), and awareness of the benefits of transplantation (OR = 0.195, 95% CI: 0.083-0.456) were less likely to deny the transplant. Patients ≤60 years of age were about 13 times more likely to favor transplantation than those >60 years of age (OR = 12.99, 95% CI: 3.75-45.45). For every 10 years under 60, participants were 2.16 times more willing to receive a kidney transplant (OR = 2.16, 95% CI: 1.53-3.02). Older patients were also less likely to be referred for evaluation (OR = 0.955, 95% CI: 0.923-0.989, P = .009).The percentage of ESRD patients in China, particularly older patients, who are willing to accept a transplant, is relatively low. A better understanding of the benefits of transplantation is needed to increase their acceptance.

Association between daily haemodialysis, access to renal transplantation and patients' survival in France

AIM

Daily haemodialysis improves patients' quality of life and blood purification, but its effect on survival remains controversial. The aim of this study was to analyze the association between daily haemodialysis and renal transplantation and survival in France.

METHODS

This was an observational cohort study based on the French REIN registry. All incident patients ≥18 years old who started daily haemodialysis in France between 2003 and 2012 were included. Using a propensity score, 575 patients on daily haemodialysis were matched with 1696 patients receiving thrice-weekly haemodialysis. Survival analysis was performed using the Cox model. Access to the renal transplant waiting list and renal transplantation were analyzed using the Fine and Gray model.

RESULTS

Daily haemodialysis was not independently associated with reduced access to transplant waiting list, whereas, major comorbidities remained associated with restricted waitlisting after multivariate analysis adjusted for confounding factors. After being waitlisted, the cumulative incidence of renal transplantation was lower for the daily haemodialysis than for the thrice-weekly haemodialysis group (SHR = 0.72, 95%CI: 0.56-0.91). The risk of death was significantly higher in the daily haemodialysis group (HR_adjusted  = 1.58, 95%CI: 1.4-1.8). Major comorbidities were associated with higher risk of death and lower likelihood of receiving a renal transplant during the follow-up period.

CONCLUSION

Our study showed that in France, the likelihood of undergoing renal transplantation after being waitlisted was lower for patients on daily haemodialysis than those on thrice-weekly haemodialysis. Moreover, daily haemodialysis was associated with higher risk of death, even after taking into account age and all major comorbidities.

Facilitating access to the renal transplant waiting list does not increase the number of transplantations: comparative study of two French regions

BACKGROUND

In France, there are important regional disparities of access to the renal transplant waiting list and transplantation. Our objectives were to compare the characteristics of patients with end-stage renal disease (ESRD) of two French regions (Ile-de-France and Bretagne) and to identify determinants of access to the waiting list and subsequent transplantation, with a focus on temporary inactive status (TIS) periods.

METHODS

All 18-80-year-old incident patients who started dialysis in Ile-de-France or Bretagne between 2006 and 2009 were included (n = 6160). Associations between patients' characteristics and placement on the waiting list or transplantation were assessed using a Fine and Gray model to take into account the competing risk of death and living donor transplantation.

RESULTS

At the end of the follow-up (31 December 2013), more patients had undergone transplantation in Bretagne than in Ile-de-France (30 versus 27%), although the percentage of waitlisted patients was higher in Ile-de-France than in Bretagne (47 versus 33%). More patients were on TIS and with a longer median TIS duration in Ile-de-France. Independent of age and clinical characteristics, patients in Bretagne were less likely to be waitlisted than those in Ile-de-France [subdistribution hazard ratio 0.77 (95% confidence interval 0.7-0.9)]. After waitlisting, patients in Bretagne were four times more likely to be transplanted.

CONCLUSIONS

Our study highlights clinical practice differences in Bretagne and Ile-de-France and shows that facilitating access to the waiting list is not sufficient to improve access to renal transplantation, which also depends on organ availability.

French patients on daily hemodialysis: clinical characteristics and treatment trajectories

BACKGROUND

Increasing the weekly frequency of hemodialysis sessions has positive effects, on the control of several biological data of patients. However, knowledge about Daily HemoDialysis (DHD) practices is limited in France. The aim of the present study was to describe the characteristics and treatment trajectories of all French patients undergoing DHD.

METHODS

All patients older than 18 years who started DHD between 2003 and 2012 in France were included and followed until December 31, 2013. The patients' demographic and clinical characteristics and treatment modalities were extracted from the French Renal Epidemiological and Information Network (REIN) registry.

RESULTS

During the inclusion period, 753 patients started DHD in France. Based on their median age (64 years), patients were classified in two groups: "old" group (≥64 years) and "young" group (<64 years). Patients in the old group had more comorbidities than in the young group: 48 % had diabetes (vs 29 % in the young group), 17 % an active malignancy (vs 10 %) and 80 % ≥1 cardiovascular disease (vs 41 %). Concerning patients' treatment trajectories, 496 (66 %) patients started with another dialysis before switching to DHD and 257 (34 %) directly with DHD. At the end of the follow-up, 69 % of patients in the old group were dead (27.4 % in the young group) and kidney transplantation was more frequent in the young group (30.4 % vs 0.5 %).

CONCLUSION

In France, DHD is proposed not only to young in rather good clinical conditions and waiting for kidney transplantation, but also to old and frail patients with higher mortality.

Survival Analysis in the Presence of Competing Risks: The Example of Waitlisted Kidney Transplant Candidates

Competing events (or risks) preclude the observation of an event of interest or alter the probability of the event's occurrence and are commonly encountered in transplant outcomes research. Transplantation, for example, is a competing event for death on the waiting list because receiving a transplant may significantly decrease the risk of long-term mortality. In a typical analysis of time-to-event data, competing events may be censored or incorporated into composite end points; however, the presence of competing events violates the assumption of "independent censoring," which is the basis of standard survival analysis techniques. The use of composite end points disregards the possibility that competing events may be related to the exposure in a way that is different from the other components of the composite. Using data from the Scientific Registry of Transplant Recipients, this paper reviews the principles of competing risks analysis; outlines approaches for analyzing data with competing events (cause-specific and subdistribution hazards models); compares the estimates obtained from standard survival analysis, which handle competing events as censoring events; discusses the appropriate settings in which each of the two approaches could be used; and contrasts their interpretation.

Influence of Socio-Economic Inequalities on Access to Renal Transplantation and Survival of Patients with End-Stage Renal Disease

Background

Public and scientific concerns about the social gradient of end-stage renal disease and access to renal replacement therapies are increasing. This study investigated the influence of social inequalities on the (i) access to renal transplant waiting list, (ii) access to renal transplantation and (iii) patients’ survival.

Methods

All incident adult patients with end-stage renal disease who lived in Bretagne, a French region, and started dialysis during the 2004–2009 period were geocoded in census-blocks. To each census-block was assigned a level of neighborhood deprivation and a degree of urbanization. Cox proportional hazards models were used to identify factors associated with each study outcome.

Results

Patients living in neighborhoods with low level of deprivation had more chance to be placed on the waiting list and less risk of death (HR = 1.40 95%CI: [1.1–1.7]; HR = 0.82 95%CI: [0.7–0.98]), but this association did not remain after adjustment for the patients’ clinical features. The likelihood of receiving renal transplantation after being waitlisted was not associated with neighborhood deprivation in univariate and multivariate analyses.

Conclusions

In a mixed rural and urban French region, patients living in deprived or advantaged neighborhoods had the same chance to be placed on the waiting list and to undergo renal transplantation. They also showed the same mortality risk, when their clinical features were taken into account.