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 at the service of the paediatric patients]

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 paediatric CKD patients, the following key messages were retained. Paediatric stage 5 chronic kidney disease (CKD) has particularities that require to be analysed and taken into account because the mortality of these patients remains 30 times higher than that of children of the same age. The REIN registry enables illustrating the specificities of stage 5 CKD in the paediatric age-group in France and providing a set of indicators making it possible to describe the future of these patients as well as the choices made concerning the modalities of replacement therapy. As compared to other European countries, the incidence and prevalence of stage 5 CKD in France is in the middle range for children under 15 and 20 years old. Renal transplant is by far the leading treatment for stage 5 CKD in children and adolescents under 18 years of age in France, allowing to offer these patients the best possible life expectancy. Owing to the small volume of patients, only a nationwide registry can provide an unbiased view and enables analysing this population requiring a hyperspecialised treatment. The participation of French paediatric nephrologists in the REIN French registry also enables providing input to the European registry (ESPN/ERA www.espn-reg.org/index.jsp) and the international registry (IPNA https://ipna-registry.org) (Consulted on September 15th 2022) and thus the possibility of international studies, which are vital to be in line with an approach to improving practices.

A systematic review of social determinants of health in pediatric organ transplant outcomes

BACKGROUND

Equitable access to pediatric organ transplantation is critical, although risk factors negatively impacting pre- and post-transplant outcomes remain. No synthesis of the literature on SDoH within the pediatric organ transplant population has been conducted; thus, the current systematic review summarizes findings to date assessing SDoH in the evaluation, listing, and post-transplant periods.

METHODS

Literature searches were conducted in Web of Science, Embase, PubMed, and Cumulative Index to Nursing and Allied Health Literature databases.

RESULTS

Ninety-three studies were included based on pre-established criteria and were reviewed for main findings and study quality. Findings consistently demonstrated disparities in key transplant outcomes based on racial or ethnic identity, including timing and likelihood of transplant, and rates of rejection, graft failure, and mortality. Although less frequently assessed, variations in outcomes based on geography were also noted, while findings related to insurance or SES were inconsistent.

CONCLUSION

This review underscores the persistence of SDoH and disparity in equitable transplant outcomes and discusses the importance of individual and systems-level change to reduce such disparities.

Impact of nephrology care trajectories pre-CKD stage 5 on initiation of kidney replacement therapy in children

BACKGROUND

To improve pre-emptive kidney transplantation (PKT) in children and limit starting dialysis in an emergency, we aimed to describe nephrology care trajectories pre-CKD stage 5.

METHODS

We included all children in France who, between 2010 and 2016, started kidney replacement therapy (KRT): standard dialysis (reference group) and emergency dialysis or PKT. We identified four pre-CKD stage 5 nephrology care trajectories before KRT that were extracted from the national exhaustive medical-administrative database and used logistic regression to explore associations between patient characteristics, care trajectories, and KRT initiation.

RESULTS

Six hundred forty-three pediatric patients started KRT in France; 406 started dialysis and 30.5% emergency dialysis. The "optimal" care trajectory encompassed 179 patients, 82.7% with at least 18 months nephrology follow-up. Conversely, the "no care" trajectory encompassed 118 patients with no nephrology follow-up before KRT. The "severe" trajectory encompassed 128 patients; 93% hospitalized more than once a year and 18% in an intensive care unit. Finally, the "irregular" trajectory encompassed 127 patients, 77% and 46% with irregular laboratory monitoring and CKD drug delivery, respectively. With the "optimal" trajectory as the reference, probability of emergency dialysis was higher with the "irregular" and "no care" trajectories (odds ratio 3.02 [95% confidence interval 1.18-7.66] and 26.5 [10.8-64.8], respectively), and PKT was reduced with the "severe" trajectory (0.43 [0.23-0.82]).

CONCLUSION

We identified a group of patients with irregular follow-up who may benefit the most from interventions aiming at improving adherence to treatment and earlier diagnosis of their CKD to improve access to PKT. A higher resolution version of the Graphical abstract is available as Supplementary information.

Kidney Transplantation in Small Children: Association Between Body Weight and Outcome-A Report From the ESPN/ERA-EDTA Registry

BACKGROUND

Many centers accept a minimum body weight of 10 kg as threshold for kidney transplantation (Tx) in children. As solid evidence for clinical outcomes in multinational studies is lacking, we evaluated practices and outcomes in European children weighing below 10 kg at Tx.

METHODS

Data were obtained from the European Society of Paediatric Nephrology/European Renal Association and European Dialysis and Transplant Association Registry on all children who started kidney replacement therapy at <2.5 y of age and received a Tx between 2000 and 2016. Weight at Tx was categorized (<10 versus ≥10 kg) and Cox regression analysis was used to evaluate its association with graft survival.

RESULTS

One hundred of the 601 children received a Tx below a weight of 10 kg during the study period. Primary renal disease groups were equal, but Tx <10 kg patients had lower pre-Tx weight gain per year (0.2 versus 2.1 kg; P < 0.001) and had a higher preemptive Tx rate (23% versus 7%; P < 0.001). No differences were found for posttransplant estimated glomerular filtration rates trajectories (P = 0.23). The graft failure risk was higher in Tx <10 kg patients at 1 y (graft survival: 90% versus 95%; hazard ratio, 3.84; 95% confidence interval, 1.24-11.84), but not at 5 y (hazard ratio, 1.71; 95% confidence interval, 0.68-4.30).

CONCLUSIONS

Despite a lower 1-y graft survival rate, graft function, and survival at 5 y were identical in Tx <10 kg patients when compared with Tx ≥10 kg patients. Our results suggest that early transplantation should be offered to a carefully selected group of patients weighing <10 kg.

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.

Setting reasonable objectives for improving preemptive kidney transplantation rates in children

BACKGROUND

This study aims to develop a method to estimate the potential of preemptive kidney transplantation (PKT) by identifying patients who were transplanted after a dialysis period (non-preemptive kidney transplantation (NPKT)) despite being medically suitable for PKT.

METHODS

All children (< 18 years old) starting kidney replacement therapy (KRT) in France, between 2010 and 2016 and transplanted before December 31, 2017, were included. A propensity score (PS) of receiving PKT was estimated by multivariate logistic regression based on recipient medical characteristics. Healthcare use during the 24 months prior to KRT initiation was extracted from the French National Health Insurance database, and a pre-KRT follow-up of more than 18 months was considered sufficient to allow preemptive transplantation.

RESULTS

Among 643 patients who started KRT, 149 (23.2%) were preemptively transplanted. Using PS stratification, among 391 NPKT patients, we identified 145 patients (37%) suitable for PKT, according to clinical characteristics. Mean age was 12.3 years, 67% were males, and 56% had urological abnormalities. Among those 145 patients, we identified 79 NPKT patients who started on dialysis despite early referral to a nephrologist (more than 18 months prior to KRT initiation).

CONCLUSIONS

This method estimates a potential of 228 (149 + 79) PKT (35%) among pediatric patients in France. A similar method could be used in adults or in other countries. Estimation of the rate of patients with CKD stage 5 medically suitable for PKT will be of interest for health policy makers when setting up objectives for improvement in preemptive kidney transplant access.

Renal transplantation in children under 3 years of age: Experience from a single-center study

RTx remains challenging in children under 3 years of age. This single-center study reviewed the medical records of children <3 years transplanted since 1987 (N = 32, Group 1). They were matched for donor type and RTx period with children aged 3-13 years (N = 32, Group 2) and 13-18 years (N = 32, Group 3). There were no between-group significant differences regarding distributions of gender, primary renal disease, proportion of dialysis before RTx, and growth (SDS). Compared to Groups 2 and 3, Group 1 had more peritoneal dialyses (P < .001), more EBV mismatches (P = .04), and longer warm ischemia times (P < .001). The risk of graft loss was not significantly different among age groups (hazard ratio, 2.4 in Group 2 and 2.0 in Group 3 vs Group 1; P = .2). Death occurred in four patients (3 in Group 1 and 1 in Group 2) and graft loss occurred in 28 patients, mainly due to chronic allograft nephropathy. In recipients <3 years of age, the outcomes of RTx are close to those obtained in older pediatric age groups. Thus, young patients may be transplanted in experienced multidisciplinary teams without additional risks provided that particular attention is paid to donor selection and prevention/early diagnosis of comorbidities and complications.

[Socioeconomic inequalities and kidney transplantation]

Studies at the population level must take into account the effect of social insecurity and socioeconomic inequalities on the patient outcomes. Socioeconomic inequalities depend on many determinants that are socially determined. In renal transplantation, these social determinants are not registered in the databases. The European Deprivation Index (EDI) is a composite index of social vulnerability with a French version. The EDI is an ecological measure of deprivation including the individual perception of basic needs for daily life that is called "subjective poverty". The Townsend index, Carstairs index and the Index of Multiple Deprivation are other ecological index available. It has been demonstrated in the United States that socioeconomic indicators of deprivation were associated with both the access to the waiting list for renal transplantation and transplantation failure. In France, socioeconomic deprivation may also affect the access to the waiting list and outcome of transplantation. This article is a review about deprivation and renal transplantation.

Between-center disparities in access to heart transplantation in France: contribution of candidate and center factors - A comprehensive cohort study

Transplantation represents the last option for patients with advanced heart failure. We assessed between-center disparities in access to heart transplantation in France 1 year after registration and evaluated the contribution of factors to these disparities. Adults (n = 2347) registered on the French national waiting list between January 1, 2010, and December 31, 2014, in the 23 transplant centers were included. Associations between candidate and transplant center characteristics and access to transplantation were assessed by proportional hazards frailty models. Candidate blood groups O and A, sensitization, and body mass index ≥30 kg/m² were independently associated with lower access to transplantation, while female gender, severity of heart failure, and high serum bilirubin levels were independently associated with greater access to transplantation. Center factors significantly associated with access to transplantation were heart donation rate in the donation service area, proportion of high-urgency candidates among listed patients, and donor heart offer decline rate. Between-center variability in access to transplantation increased by 5% after adjustment for candidate factors and decreased by 57% after adjustment for center factors. After adjustment for candidate and center factors, five centers were still outside of normal variability. These findings will be taken into account in the future French heart allocation system.

Gender Disparities in Access to Pediatric Renal Transplantation in Europe: Data From the ESPN/ERA-EDTA Registry

Inequalities between genders in access to transplantation have been demonstrated. We aimed to validate this gender inequality in a large pediatric population and to investigate its causes. This cohort study included 6454 patients starting renal replacement therapy before 18 years old, in 35 countries participating in the European Society for Paediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry. We used cumulative incidence competing risk and proportional hazards frailty models to study the time to receive a transplant and hierarchical logistic regression to investigate access to preemptive transplantation. Girls had a slower access to renal transplantation because of a 23% lower probability of receiving preemptive transplantation. We found a longer follow-up time before renal replacement therapy in boys compared with girls despite a similar estimated glomerular filtration rate at first appointment. Girls tend to progress faster toward end-stage renal disease than boys, which may contribute to a shorter time available for pretransplantation workup. Overall, medical factors explained only 70% of the gender difference. In Europe, girls have less access to preemptive transplantation for reasons that are only partially related to medical factors. Nonmedical factors such as patient motivation and parent and physician attitudes toward transplantation and organ donation may contribute to this inequality. Our study should raise awareness for the management of girls with renal diseases.

Inequalities in access to pediatric ESRD care: a global health challenge

The increasing attention paid to chronic kidney disease (CKD) as a major cause of mortality and disability, as well as the advances in management of CKD in children, have created a growing demand for pediatric renal replacement therapy (RRT) worldwide. A study by Koch Nogueira and colleagues of children on the transplant waiting list showed large disparities in access to pediatric kidney transplantation between regions in Brazil. This finding raises a wider question about inequalities in access to CKD care in children. Here we review the available data on the global burden of end-stage renal disease in children, the need for pediatric RRT, and its actual provision worldwide. We focus on inequalities in access to renal care for children that currently exist between and within countries. Reduction in worldwide inequalities in access to RRT in children remains a challenge, which requires greater awareness and effective interventions and policies.