Every year about 9 children per million children develop end-stage kidney disease (ESKD) and require dialysis or a kidney transplant. ESKD is a rare condition, and its treatment is complex and expensive. Low patient numbers per country complicate clinical epidemiological research and hamper the development of evidence-based guidelines. This results in large variation of treatment practices and outcomes across Europe. Therefore, the European Society for Paediatric Nephrology (ESPN) and the European Renal Association and European Dialysis and Transplantation Association (ERA-EDTA) have initiated the ESPN/ERA-EDTA Registry. This specialized network collects prospective data on all European children on dialysis or with a kidney transplant.

The Academic Medical Center (AMC) in Amsterdam, the Netherlands, one of the world`s leading medical centres, hosts the ESPN/ERA-EDTA registry and takes care of its financial management.

The ESPN/ERA-EDTA Registry MISSION is to provide high-quality information on all European children on dialysis or with a kidney transplant.
To achieve this mission, we pursue the following activities:
(1) Collect standardized data on children on dialysis or with a kidney transplant from 35 European countries on a yearly basis;
(2) Regularly publish demographic information on paediatric ESKD;
(3) Perform research projects focusing on
- Transnational differences in paediatric ESKD treatment, aiming at reducing health inequalities
- Rare diseases leading to ESKD in children
- Defining optimal strategies to harmonize and reduce practice variation in ESKD management
The demographic information and research results are disseminated online, emailed to all members and contributors, published in high-quality medical journals and presented at national and international congresses.
Covering a population of 630 million in 35 European countries, the ESPN/ERA-EDTA registry is the world`s largest population-based registry for children with ESKD. Our VISION is to provide access to high quality, evidence-based clinical care to all European children.

Prioritized fields of study in the AMC include, amongst others, the consequences of relative wealth on the level of health, and differences in health as related to ethnicity. Researchers are devoting much time and effort to projects that promote health care in non-Western countries.

The ESPN/ERA-EDTA Registry contributes substantially to these AMC objectives, as well as to the EU Work plan 2012, collecting comprehensive data, and carrying out research projects in order to increase knowledge on health care quality, determine best practice in organ donation, transplantation and dialyis in European children, aiming at reducing practice variation and inequalities in health care provision within Europe, and by studying the implications and challenges brought about by rare kidney diseases.
The Registry tries to achieve these aims via 3 core activities: (A) Annual collection of comprehensive clinical, treatment-related and biochemical data from children on dialysis or with a kidney transplant, (B) provision of demographic information, and (C) execution of specific research projects.

(A) Annual data collection. As part of the European Nephrology Quality Improvement Network (NephroQUEST), an EAHC sponsored project, in 2007 a standardized list of items for data collection adapted for children was developed. Data are collected as part of routine clinical practice without performing additional measurements and are provided to the Registry in an anonymous format. Therefore patient confidentially is guaranteed and usually no approval from ethical committees is needed. Otherwise this is organized at a local level. In the future, we will include bench-marking features to the internet-based data collection, thereby providing direct feed-back on multiple clinical parameters on a patient level. We hope in doing so to reduce practice variation between centres and countries.

(B) Demographic information. The work of the registry provides transparency about country- or region-specific differences in the access of affected children to renal replacement therapy, and stimulates research about the reasons underlying such differences. As far as these are of non-medical nature, the registry activities are aimed at paving the way to equal access to dialysis and transplantation for children throughout Europe.

(C) Execution of specific research projects, which contribute in multiple ways to the objectives of the EU work plan 2012.
(1) Our investigations into transnational differences in medical management and outcomes are aimed at defining uniform treatment quality standards to reduce practice variation, but also at determining cost-efficient utilization of resources in this resource-intense field of high-end medicine.
(2) We are studying longitudinally factors potentially impacting long-term health outcomes, such as hypertension, dyslipidemia and obesity, thereby contributing importantly to the issue of healthy ageing of children with chronic diseases.
(3) We study the relationship of transplantation practices and policies with long-term patient outcomes, thereby determining best practices in organ donation and transplantation.
(4) We study specific rare kidney diseases such as haemolytic uremic syndrome, primary hyperoxaluria, and Henoch Schönlein purpura nephritis. Large networks are needed to study such rare disorders. We can provide information on epidemiological trends and evaluate the specific challenges of care of children with these disorders relative to the "common" patient.
(5) Finally, an important component of our work is the evaluation and adjustment of currently used methodologies in paediatric nephrology. In paediatrics, many diagnostic procedures and therapeutic interventions require standardization for changing body dimensions. As children with ESKD are often growth retarded, many measures and interventions need to be adjusted for the altered age-height/weight relationship. The availability of a large registry database allows for the first time to recalibrate allometric principles in paediatric nephrology.

The ESPN/ERA-EDTA registry identified 4 key activities and projects for its 2013 work programme. We are planning to (1) continue prospective data collection, (2) expand data collection with respect to specific treatment policies, (3) implement an automated direct feed-back function to members and contributors and (4) carry out and publish scientific data analyses on specific topics of interest.

(1) We will continue collecting individual patient data from all contributing countries, and combine these datasets into a single database. This database will be used to provide national reports to the countries, write an annual report and provide patients`
information to perform the research projects outlined below.

(2) To obtain more detailed information on the current country-specific treatment practices, we will in the first quarter of 2013 carry out a web-based questionnaire project asking contributing sites about utilization of resources and pharmaceutical treatment policies (including growth hormone, erythropoiesis-stimulating and immunosuppressive agent utilization and protocols). The information obtained will be correlated with clinical outcome measures, and the results of the studies will be made available to the professional community and policy-makers.

(3) We plan to implement tools in the online database menu that allow for direct feed-back to contributing sites and countries. For example, we will provide information on the prevalence and patient-specific degree of growth failure, malnutrition, overweight/obesity and hypertension.
Furthermore, we plan to develop a benchmarking tool indicating the performance of each country, relative to the overall population, regarding a set of Key Performance Measures. In this way, we hope to stimulate efforts within the European Network to strive for harmonized treatment quality and reduced practice variation. The first step towards this goal, to be achieved in 2013 by a process of peer interrogation and consensus formation, will be the development of a list of prioritized Key Performance Measures for patients on dialysis and post-transplantation.

(4) The main measurable outputs of the objectives set out for the year 2013 will be scientific publications in peer reviewed journals:
(a) We aim to disseminate demographic information on paediatric dialysis and transplantation, both with respect to actual findings and their potential relationship to economic factors and national policies.
(b) We plan to provide information on policies regarding optimization of statural growth and their implication in practice.
(c) Another project will be on the differences in patient and graft survival across regions in Europe. We want to assess whether transplantation policies and economic status affect the patient and graft survival in the regions.

Several analyses of rare kidney diseases will be completed in 2013. We plan to produce publications on:
(d) Autosomal Recessive Polycystic Kidney Disease, a very rare disorder with 50% mortality in the first year of life. One third of the patients who survive to age 10 years are in need of renal replacement therapy.
(e) Finnish type nephropathy, a rare recessive disorder of selectively high incidence in Finland.
(f) Infant dialysis, although not a rare disease, children who have to start in the first years of life are a very specialy rare subgroup, which requires additional information. An expert in this field from Italy will collaborate on this topic and visit the AMC for two times two weeks.

Finally, we aim to continue our successful internship program for interested junior paediatric nephrologists from all over Europe. So far the Registy Office has hosted "interns" from France, Italy, Germany, the UK and the Netherlands, who performed research projects for various periods (1 week to 1 year). We will promote further research visits to the AMC as part of the implementation of the dissemination and outreach activities.

Whereas funding to perform the core activities (1) has been secured, additional co-funding will be required to address specific research issues, focusing on understanding of health inequalities, resource availability and utilization, cardiovascular ageing and specific aspects of rare kidney disorders.