Fresenius Medical Care, Bad Homburg, Germany
Keywords: demographics; end-stage renal disease; haemodialysis; peritoneal dialysis; prevalence; worldwide
Introduction
The number of patients treated for end-stage renal disease (ESRD) has demonstrated continuous growth since the establishment of dialysis as a life-sustaining therapy and advances in organ transplantation. This growth in ESRD patients is five times the world population growth (1.3%) and continues to grow beyond all early expectations, showing no sign of reaching a steady state within the next two decades. Reasons contributing to this growth are generally considered to be the globally ageing, multi-morbid population, higher life-expectancy of treated ESRD patients and increasing access of a generally younger patient population to treatment in countries in which access to date has been limited. Additionally, developments to either prevent renal disease or provide a superior and financially viable replacement therapy are not expected in the foreseeable future [1].
Over the years, data from renal registries have provided valuable information on renal patients. The first registry report of the European Renal Association (EDTA) was published in 1965 [2]. With only 271 patients admitted to treatment, the establishment of this registry demonstrated admirable foresight on the part of the collaborators in addressing an issue that would later confront healthcare organizations worldwide [35]. The motivation of the early pioneers to implement the necessary complex processes arose from the perceived benefit in pooling of patient and clinical data from a large number of clinics for the purpose of obtaining statistics on patient demographics and analysis of experience. Today, renal registries and other official organizations in numerous countries continue to present a valuable source of extensive information on various aspects of ESRD demographics, treatment practices and, increasingly, outcomes [623]. This information provides a base for international comparisons and aids understanding of treatment practices and policies and their implications for the well being of patients. The conclusions that can be drawn from such considerations are able to provide knowledge of value to both the medical communities and policy makers throughout the world.
At a national level, data collection and analysis requires extensive resources to enable timely reporting of results. The collection of data reflecting the situation in a number of countries presents additional challenges that may render timely reporting of data a difficult target to achieve. For this reason, a project was established to develop a contemporary database providing global ESRD demographic information. The results presented consider data collected and analysed from 120 individual countries within the scope of a survey developed to address various aspects associated with the treatment of ESRD patients. Information regarding patient demographics, global patient distribution, treatment practices and trends is presented.
Methods
Based on the Fresenius Medical Care dialysis network structure, 120 countries with established dialysis programmes were identified. Three survey forms based on a catalogue of 12 different topics relevant to the treatment of ESRD patients were compiled. The survey forms were prepared in English and in some cases the relevant local language. The survey focused on the total number of patients treated, the modality selected, trends in treatment practices, products used, treatment location, healthcare and ESRD patient care structure and funding. Depending on the assessment of the ESRD patient care infrastructure in the 120 countries, one of the three survey forms was sent to professionals in the field of dialysis with regard to data insertion for the respective country. Whereby the degree of detail concerning the information requested on ESRD patients and treatment practices varied, the design of the surveys was such that information could be consolidated and compiled in one database. Demographic and economic data were completed centrally from publicly available internationally recognized sources [2426]. Surveys from the 120 countries were returned within the first 3 months of 2002. The surveys were centrally validated by cross-referencing with the most recent sources of national information (e.g. registry data) available concerning the requested information as well as with the results of earlier internal analyses performed over the previous 3 year period. Furthermore, each survey underwent an automatic validation process whereby input fields with related information were linked and checked for consistency. All surveys were consolidated at different regional levels within a database whereby the validation checks were repeated for groups of countries as relevant. The results presented are derived from the database with data consolidated for 120 countries. The results represent the data as of year-end 2001. All growth rates indicate the full year growth from 2000 to 2001 based on the number of patients at year-end 2000 and 2001.
Results
Countries considered
The countries for which surveys were completed are listed in Table 1. These 120 countries, with a combined population of 5.7 billion, represent 90% of the world population and provide treatment to an estimated 99% of the treated ESRD population.
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Patients and treatment modality
In 2001, 1 479 000 people were undergoing treatment for ESRD. Of these, 338 000 were living with a donor organ, 1 015 000 underwent haemodialysis (HD) and 126 000 peritoneal dialysis (PD) (Figure 1). The resulting average global prevalence of treated ESRD and dialysis patients was 240 and 185 patients per million population (p.m.p.), respectively (Table 2
). Prevalence ranged from <10 p.m.p. (noted in 13 countries in the case of treated ESRD patients in total and in 15 countries in the case of ESRD patients undergoing dialysis) to >1700 p.m.p. Worldwide, the highest prevalence was reported in Japan followed by Taiwan and the USA. In these countries prevalence rates were >1400 and 1000 p.m.p. for treated ESRD and dialysis patients, respectively. Portugal and Italy reported the highest prevalence rates within Europe for both ESRD and dialysis patients (7331085 p.m.p.). Notably, the average prevalence for both treated ESRD and dialysis patients in Europe was lower than that in the USA and Japan. In Latin America the highest prevalence rates were reported in Uruguay, Chile and Argentina (485703 p.m.p.). Results demonstrate considerable variation in prevalence between the designated regions. Additionally, considerable intra-regional variations were evident. In Asia (excluding Japan), for example, a prevalence of
28 p.m.p. was reported for China while in Taiwan the prevalence was >1400 p.m.p.
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Haemodialysis patients
The global distribution of HD patients is shown in Figure 3. In the three major individual regions shown (European Union, Japan and the USA) the HD population demonstrated a growth rate of 56%, while in the region other (all other regions/countries) an average growth rate of 10% was reported. Again, significant regional and country variations were observed.
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Table 4 shows trends in HD reflecting some key parameters and practices in HD.
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Haemodiafiltration with online preparation of substitution fluid was the treatment modality showing the highest growth (+23%) in this time period. It should be noted that only a relatively small patient population was treated with this modality (<2% globally; >15% in selected European countries). Data relating to reuse were requested from 96 of the 120 countries considered. From the data reported it could be concluded that there was a global decrease in reuse from 2000 to 2001. Low penetration of reuse practices was evident in Europe, Africa, the Middle East and Japan. High penetration of reuse was indicated by data from countries in Latin America, Asia Pacific (excluding Japan) and North America. Of the 96 countries providing data on reuse, 25 reported that the practice of reuse dominated and in only eight of these countries could a decrease be reported from 2000 to 2001. However, reuse growth in Latin America and Asia Pacific was below the dialysis patient growth in these regions. Notably, North America showed a decline in the number of patients reusing dialysers.
Peritoneal dialysis patients
Analysis of global peritoneal dialysis patients indicated a regional shift in the patient distribution from Japan to further countries in Asia and Latin America (Figure 4). This may be considered a result of the low penetration of peritoneal dialysis in Japan, where
5% of patients were treated with this modality, and from the relatively high penetration of PD in two major countries in Latin America and Asia. As previously noted, large PD patient populations, relevant to HD, were reported in Mexico and the Republic of Korea.
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Discussion
At the end of 2001, 1 479 000 patients were being treated for ESRD representing an increase of 7% compared with year-end 2000. The number of patients living with a donor organ or undergoing HD increased by 7% and those undergoing PD increased by 5%. Only four of the 120 countries considered in this study reported a decline in the total ESRD population from 2000 to 2001.
At the end of 2001, of the treated ESRD patients, the majority was treated by HD (69%), followed by organ transplantation (23%) and the minority by PD (8%). In general, this modality implementation and/or selection pattern was reflected in the 120 countries considered with few notable exceptions. Mexico reported a higher allocation of patients to PD than HD while the UK, Spain, Australia and Nordic countries reported higher relative patient populations living with a donor organ than the global average. Based on the analysis of early registry reports and comparison with data reported within this study, it can be concluded that other than an 5% shift from HD to transplantation over the years, no major reallocation of patients between the three treatment modalities is apparent in the last 25 years. A trend towards what may be considered better treatment modalities or practices appears to be indicated by analysis of the global data. The number of patients treated with synthetic membranes increased during 2001, as did the number of high flux and higher adequacy treatment modalities. A concomitant decrease in the practice of reuse was reported. Similarly, the increase in the selection of APD evident in 2001 again may be considered indicative of a trend towards higher adequacy dialysis modalities.
A validation process was an integral part of the data collection and analysis procedure. Data were compared with those from registries and other publicly available sources. It should be noted that direct comparison with statistics from other sources was seldom possible due to the contemporary nature of this survey. Concerning patient numbers, no other source of information for treated ESRD patients in 2001 could be identified at the time of data analysis. To enable a validation of patient numbers, the most recent data available from recognized sources were extrapolated to 2001 based on the reported growth rates from these sources. A comparison of patient numbers derived in this manner with the numbers reported in this study resulted in a deviation of ±<5% for the majority of countries. A higher deviation was evident for some countries for which reports are generally sporadic, growth rates unpredictable and in cases where only patient subpopulations within the country were considered.
Such studies may facilitate prognosis of patients undergoing treatment for ESRD in the coming years. Based on this data we can expect the number of patients undergoing treatment to increase to 2 million by year-end 2005 and to 2.5 million by 2010. A significant change in the regional distribution of patients may also be expected with an increasing population located outwith the three major regions (USA, Japan and EU) considered here. Remarkably, this prognosis matches an estimate made almost 10 years ago by Woods [27] who estimated that by 2010 the number of chronic dialysis patients would have increased to 2.5 million and that those in the developing countries would match patients in the developed countries. With hindsight, this must be considered to be one of the most accurate prognoses of its time.
Consideration at the country level of patient demo<1?show=[dh]>graphics, development trends and treatment resources available provides further insight into the situation in each country and should be considered in any development prognosis to challenge numbers on predicted patient populations. Analyses alone of the global average prevalence (ESRD 240 p.m.p. and dialysis 185 p.m.p.), the global prevalence range (<50 to >1500 p.m.p.) and the wide variation in growth rates (<0 to >30%) indicate widely varying situations in different countries. The age structure and co-morbidity of a given population as well as dialysis treatment practices and outcomes influence both the incidence of renal disease and the development of the ESRD population. Developing countries in particular are generally characterized by a lower age of the general population and further the average age of a patient commencing dialysis is considerably lower in the developing countries than the developed countries, a fact with economic implications. Furthermore, economic resources are required to sustain a dialysis population, again underlining potential errors in assessing the dialysis patient population based on extrapolation of patient populations based on current growth rates. A comparison of national economic strength (expressed as gross domestic product (GDP)) with prevalence of ESRD suggests that economic factors impose restrictions to treatment. An association may be assumed between ESRD patient prevalence and GDP for a country in which the GDP per capita is below a limiting value (Figure 5). The absence of such a correlation in the countries of the European Union suggests that following attainment of a certain economic wealth, factors other than economics dominate in determining incidence and prevalence of ESRD. Approaches that enable establishment of ESRD and, more specifically, dialysis programmes in countries with restrictive economic resources and generally younger patient populations may result in future patient numbers significantly in excess of those derived with the currently reported growth rates. ESRD patients in China and India would have represented
30% of the global dialysis population at the end of 2001 if prevalence rates in these countries were 200 p.m.p.a number significantly below the global average but far beyond the current prevalence rates in these two countries of
30 and 14 p.m.p., respectively.
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Acknowledgments
We would like to express our thanks to those people providing data from 120 countries worldwide; without their collaboration, this report could not have been prepared.
Notes
Correspondence and offprint requests to: Gail Brown, Fresenius Medical Care, Else-Kroener Strasse 1, D-61352 Bad Homburg, Germany. E-mail: gail-suzanne.brown{at}fmc-ag.com
References