NEFROLOGÍA. Vol. XXV. Número 2. 2005 The Year 2002 Spanish Nephrology Society Report on Dialysis and Transplantation and Autonomic Registries M. Ceballos1, K. López-Revuelta1, R. Saracho1, F. García López1, P. Castro2, J. A. Gutiérrez3, E. MartínMartínez4, R. Alonso4, R. Bernabéu5, V. Lorenzo6, M. Arias7, T. Sierra8, C. Estébanez9, M. Lara9, M. Clèries10, E. Vela10, M. J. García-Blasco11, O. Zurriaga11, C. Vázquez12, A. Sánchez-Casajús13, R. Rodado14, J. Ripoll15, J. L. Asín15 y A. Magaz16 SEN Registry Committee, Autonomic Registries and Communities of: 2Andalusia (R), 3Aragon, 4Asturias(R), 5Balearic Islands, 6Canary Islands(R), 7Cantabria(R), 8Castile-La Mancha(R), 9Castile-Leon(R), 10Catalonia(R), 11Commutity of Valencia(R), 12Estremadura(R), 13Galicia, 14La Rioja, 15Navarre, 16Basque Country(R). 1 INTRODUCTION In the present report, available information is given about End-Stage Chronic Renal Failure (ESCRF) and its treatment in Spain during the year 2002. It has been elaborated by the Group on Registry of Renal Diseases (GRRD), as it has been doing so since 1996. This group is comprised by representatives of the Autonomic Registries and of the SEN Registry Committee. For the communities of Aragon, Murcia and La Rioja, in which an autonomic registry has not yet been created, the information has been provided by interested nephrologists, and we do not have the data from the Community of Madrid and from the Autonomous Cities of Ceuta and Melilla. In this report, as usual, issues related to etiology of renal failure, age distribution, incidence, prevalence, treatment modalities, lethality and its causes during the year 2002 are considered, as well as the comparison of these data with those of some international registries. METHODS According to the methodology established in previous years, this report has been done by compounding the data of a questionnaire in Excel for- mat sent to the persons in charge of the autonomic registries. Asked data were: number of incident and prevalent patients, and deaths to date December 31st of 2002. These data were gathered distributed by gender, age, and type of renal replacement therapy (RRT). The cause of renal disease in incident patients and cause of death in deceased were asked; the codification used has been the one proposed by the EDTA (appendixes I and III). Global estimates for Spain were obtained by extrapolating to the 100% of the population the prevalence and incidence rates, assuming that communities that do not present data do not deviate from the mean. Calculations on cumulative incidence were done by dividing the number of new patients by the number of inhabitants at the beginning of year 2002. For computation of prevalence rates, the population used in the denominator was the one at December 31st of 2002. Besides crude incidence and prevalence Appendix I. Equivalence of etiologic groups according to the EDTA codification system Primary renal disease Glomerulonephritis Pyelonephritis/Interstitial nephritis Polycystic disease Hereditary/Congenital Vascular Diabetic nephropathy Systemic Others Unknown EDTA codes 10-17, 19 20-25, 29-34, 39, 92, 93 41 40, 42, 43, 49-54, 59-66 70-72, 75, 79 80 73, 74, 76, 78, 82-89 90-00 (except 92 y 93) 00 Correspondence: Dr. Manuel Ceballos Guerrero Hospital Puerta de Mar Ana de Viya, 21 11009 Cádiz E-mail: mcebal@telefonica.net 121 M. CEBALLOS y cols. Appendix II. Equivalence of death causes according to the EDTA codification system Death cause Cardiac Vascular Sudden death Infectious Cancer Hepatic Gastrointestinal Psychological/Social Accident Others Not determined EDTA code 11-18 21, 22, 26, 29 01 31-39, 70, 100-102 66, 67 41, 46 23, 62, 71, 72 51-54 81-82 24, 25, 27-28, 63, 64, 69, 73, 99 00 Spanish population are based on the latest data published in the web page of the National Institute of Statistics (INE)4. RESULTS Studied population The percentage of studied population is slightly higher than the one of previous years, with incorporation of data from Estremadura. In global, the covered population represents 35,130,638 persons, more than 86% of the Spanish population. Incidence rates, we calculated community of residence-adjusted rates. For analysis of mortality rates we used the quotient yielded by dividing deceased people during their last treatment modality by the number of prevalent patients at December 31st in the same modality plus the afore mentioned deceased. The resulting rate has been expressed in percentage. In order to provide a wider overall view of RRT in Spain, some transplantation data have been taken from the ONT (National Transplantation Organization) report corresponding to the year 20021. In addition, comparative data with other registries are presented, such as the European (EDTA)2 and the USA (USRDS)3 registries, and other national registries. Population data, cause of death and lethality in the During that year, 4,612 people started on replacement therapy (Table I), which means an incidence of 131 patients per million population (pmp). If we extrapolate this number to the total Spanish population, it would represent 5,596 patients having initiated treatment. What is being observed for several years is confirmed, that is, a great disparity between communities (Table II); that year, the highest rate has occurred in the Balearic Islands with a rate of 170 pat/pmp, exceeding the one of the Canary Islands that had the highest incidence in the year 2001, and there are others with much lower rates, such as Aragon and the Basque Country, which are below 100 pat/pmp. Since 1996, the incidence is steadily increasing (Fig. 1), with a mean annual in- Table I. Incidence of patients on renal replacement therapy in Spain in the year 2002 and distribution by treatment modality used Community Aragon Basque Country Castile and Leon Castile and La Mancha Andalusia Cantabria Estremadura Murcia (Region of) Asturias (Principality of) Galicia Navarre Catalonia Canary Islands Community of Valencia Rioja (La) Balearic Islands HD pmp 87 66 86 98 108 88 111 115 122 107 106 139 132 139 156 161 N HD 101 137 206 171 797 47 121 133 127 295 58 873 234 576 42 133 PD pmp 2.5 24.1 13.1 13.9 9.3 24.5 10.2 13.9 10.5 34.8 33 9.8 23.1 16.7 0.00 9.7 N PD 3 50 42 24 68 13 11 16 11 95 18 61 41 69 0 8 Tx pmp 0.00 2.9 1.6 0.6 0.4 5.6 0.00 0.00 3.8 1.1 5.5 2.7 0.00 0.2 0.00 0.00 N Tx 0 6 0 1 3 3 0 0 4 3 3 17 0 1 0 0 Global pmp 89 93 101 113 118 119 122 129 136 143 145 152 155 156 156 170 Population 1,166,380 2,070,831 2,459,551 1,729,940 7,338,863 530,640 1,081,215 1,153,635 1,049,127 2,732,926 543,554 6,260,065 1,777,884 4,139,168 268,844 828,190 122 SPANISH DIALYSIS AND RENAL TRANSPLANTATION REGISTRY-2002 Table II. Prevalence of patients on renal replacement therapy in Spain in the year 2002 and distribution by treatment modality used in the autonomous communities Community Andalusia Aragon Asturias (Principality of) Balearic Islands Canary Islands Cantabria Castile and La Mancha Castile and Leon Catalonia Community of Valencia Estremadura Galicia Murcia (Region of) Navarre Basque Country Rioja (La) Global HD pmp 494 353 340 503 458 226 424 454 547 634 508 343 469 301 257 489 425 N HD 3,755 435 356 476 868 124 771 981 3,665 2,637 545 961 595 174 523 141 17,167 PD pmp 39 4 29 23 48 72 43 63 30 52 47 86 41 37 89 48 47 N PD 299 5 30 22 92 39 77 133 206 217 51 236 53 21 186 14 1,708 Dialysis total 4,053 440 396 498 960 163 848 1,286 3,871 2,854 596 1,179 648 195 732 155 18,875 Tx pmp 358 451 466 269 465 457 432 359 477 396 320 465 340 536 503 478 423 N Tx 2,727 554 488 255 881 251 784 890 3,196 1,647 343 1,273 432 310 1,042 137 15,255 Global pmp RRT Total 891 808 834 794 972 754 899 876 1,054 1,082 875 894 851 873 849 1,016 895 6,780 994 897 753 1,841 414 1,632 2,180 7,067 4,501 939 2,470 1,080 505 1,751 292 34,129 crease in that period somewhat higher than 3%, varying from 107 in 1996 to 131 pat/pmp in 2002. ESCRF is a disease that mainly affects the elderly patients (Fig. 2), with a remarkable incidence increase as age increases, being 10 times more frequent in the age group of 65 to 75 years than in the young age group of 15 to 44 years. The global mean being 131 pat/pmp, it raises to 429 in the age group 65 to 75 years and decreases a little bit in people older than 75. Prevalence At the end of the year 2002, there were a total of 34,129 patients in RRT in the collection of communities that provided data; of them, 17,167 (59%) were on hemodialysis, 1,708 (5%) were on perito- neal dialysis, and 15,255 (45%) had a functioning renal transplantation (Table II). In relative terms, the global prevalence was 895 pmp, which means a slightly increase over the year 2001 rate, which was 885 pmp. There are some communities such as Catalonia, the Community of Valencia and La Rioja that exceed 1,000 pat/pmp. Evolutionary data on prevalence and incidence since 1996 are shown in Figure 1, in which an increase in prevalent patients from 702 in 1996 to 895 pmp in 2002 is observed. The number of treated patients has increased by 27% from 1996 to 2002, with a mean increase rate of treated population of nearly 4% annual. The prevalence is increasing since the number of deceased patients is lower than the number of patients that start treatment. The increase in incidence runs parallel to the increase in prevalence. 200 150 Incidence 100 50 0 Incidence Prevalence 1996 1997 1998 1999 2000 2001 2002 107 702 114 745 123 763 126 811 132 845 128 880 131 895 1,000 900 800 700 600 500 400 300 200 100 0 500 400 Prevalence pat/pmp 300 200 100 0 pmp 0-14 6 15-44 40 45-65 173 65-74 429 > 75 399 mean: 131 pat/pmp Fig. 1.--Incidence and prevalence progression, pmp, years 96-02. Fig. 2.--Incidence by age groups in the year 2002. 123 M. CEBALLOS y cols. Rioja (La) Aragon Balearic Islands Catalonia Asturias Andalusia Estremadura Valencia Castile La Mancha Castile and Leon Canary Islands Cantabria Navarre Galicia Basque Country 0% 20% 40% 60% 80% 100% PD HD With regards to prevalent treatment modalities, 55% of patients are treated with dialysis in both modalities and 45% are submitted to transplantation although there exist some differences between communities; in some of them the number of transplanted patients surpasses the number of patients on dialysis (fig. 4), being such that Navarre and Cantabria exceed 60% of transplanted patients. On the other hand, the Balearic Islands, Valencia and Estremadura have more than 60% of patients treated with dialysis. In the prevalent treatment modality there are very important differences by age group (Fig. 4), so that transplantation is more frequent with a lower age and peritoneal dialysis is somewhat more frequent in the very young and the very old. Renal failure causes In the year 2002, almost one fourth of renal failure cases that reach replacement therapy are of unknown etiology, followed by diabetes and nephropathy from a vascular origin (Fig. 5). The causes of ESCRF are very diverse depending on age groups (Table III), and thus, the most common causes of RRT initiation in patients younger than 15 years are hereditary diseases and chronic pyelonephritis, glomerular diseases in young patients aged 15-44 years, and renal vascular and of unknown origin diseases in the elderly. Fig. 3.--Initial dialysis treatment modality. Treatment modalities The starting RRT modality is by large hemodialysis, with a great difference in use of peritoneal dialysis (Fig. 3). In the Basque Country, Galicia, Navarre, and Cantabria more than 20% of new incident patients start on peritoneal dialysis, whereas in Catalonia, La Rioja, Asturias, and Andalusia this percentage does not exceed 10%. The number of anticipated transplantations is very small, around 1%, although in some cases, such as Cantabria, it goes up to 4%, but this figure is little significant because it is a community with just one province, with a small population, being only three patients in absolute terms. Not known DM Vascular CGN In % CPN Others RPD 6 2 0 5 10 15 8 10 14 17 22 21 100% 80% 60% 40% 20% 0% 0-14 15-44 Hemod. PD 45-65 Tx 65-74 Hereditary 20 25 Fig. 4.--Prevalent treatment modality by age. Fig. 5.--Renal failure causes. 124 M. CEBALLOS y cols. Table III. Incidence of ESCRF causes by age groups Age group 0-14 15-44 45-64 65-74 > 75 CGN 0.9 11.9 33.8 38.5 24.5 CPN 1.4 5.9 15.4 30.6 34.7 DM 0.0 5.3 39.7 111.2 62.9 VASC 0.4 2.5 21.0 73.9 98.3 RPD 0.0 3.6 17.4 23.0 10.2 Hered 1.4 2.4 3.2 6.1 1.1 Systemic 0.7 3.3 9.5 23.0 19.6 Others 0.4 1.1 6.4 17.0 10.9 Unknown 0.0 5.8 33.6 95.4 124.7 Population 5,589,787 15,661,154 7,703,216 3,301,569 2,653,864 CGN: chronic glomerulonephritis. CPN: chronic pyelonephritis. DM: diabetes mellitus. Vasc: Vascular. RPD: renal polycystic disease. Hered: Hereditary. Mortality In that year, 3,224 deaths were notified, which means a mortality rate of 92 pmp, calculated with population covered in this report. This represents a 9.5% crude global rate, with remarkable differences depending on modality, being similar with peritoneal dialysis and hemodialysis, and notably lower in transplanted patients. Global mortality progression is shown in Table IV in relation to the latest modality since 1996. The crude mortality for dialysis is 13.6%, which has been similar for the last several years5. The annual progression of dialysis mortality rate is shown in Figure 6. The main mortality causes are similar for the three treatment modalities and are summarized in Figure 7; the two most important causes are cardiovascular disease and infection, whereas cancer as mortality cause is much more frequent in transplanted patients. There is an important number of death causes registered as unknown and sudden deaths, many of them probably being of cardiovascular origin. 20 18 16 14 12 % 10 8 6 4 2 0 1996 1997 12.5 13.6 Mean annual rate: 13% 13.5 13.5 13.8 11.5 13.6 1998 1999 2000 2001 2002 Fig. 6.--Progression of crude annual mortality rate for dialysis. Transplantation activity During the year 2002, 2,032 transplantations were performed, which is the biggest number ever performed, although in the last several years the number 40 35 30 Table IV. Global mortality progression (in percentage) by last type of renal replacement therapy from 1996 to 2002 HD 1996 1997 1998 1999 2000 2001 2002 11 12.5 13.8 13 13.4 13 14.5 PD 14 14.7 13.2 14 14.2 10 12.7 Tx 2 1.7 1.7 2 1.9 1.7 1.5 25 % 20 15 10 5 0 Cancer PD Hemod. Tx Cariovasc. Infectious Unknown Others Sudden 4 7 15 27 36 24 31 28 31 16 11 12 15 15 13 5 4 2 Fig. 7.--Summary of death causes by treatment modality. 126 SPANISH DIALYSIS AND RENAL TRANSPLANTATION REGISTRY-2002 2,100 England 1,900 1,700 1,500 1,300 1,100 Transplantations 601 781 895 918 1,097 1,446 1,726 0 200 400 600 800 1,000 1,200 1,400 1,600 1,800 pmp Austria Spain Germany Portugal USA 1990 1996 1997 1998 1999 2000 2001 2002 1,240 1,707 1,861 1,996 2,023 1,938 1,924 2,032 Japan Fig. 8.--Annual progression in transplantations numbers. Fig. 10.--Comparative international prevalence. of transplantations became stable, of around 2,000 transplantations; the rate of transplantation from cadaver is 48.6 pmp, which is the highest in the World. Comparison with other registries The incidence of new patients is Spain is within the European mean, with an incidence rate higher than that of United Kingdom and Holland, similar to that of Italy, and lower than that of Germany and Portugal, the later having the highest rate in Europe of 200 pmp, and well below those of the USA and Japan that exceed 300 pat/pmp. The prevalence rate is one of the highest in Europe, similar to that of Germany and lower than that of Portugal, which has the highest rate in Europe of 1,097 pat/pmp, although it is much lower than that of the USA and Japan, the later having the highest rate in the World of 1,726 pat/pmp (Fig. 10). As it happens in Spain, the frequency of peritoneal dialysis utilization is highly variable from one country to another (Fig. 11). The 5% Spanish frequency is far from the numbers in countries such as Canada, United Kingdom and especially New Zeeland with 44% and Mexico that reaches 80% of patients on peritoneal dialysis. Mortality rate in Spain is somewhat lower than the one in Europe, as reported in the DOPPS study6, notably lower than that of the USA, and higher than that of Japan (Fig. 12). DISCUSSION The population covered this year is the highest ever reached, and communities not included in the study are in the process of elaborating their registries, so it is likely that in the coming years it will be possible to gather data from the entire Spanish population. The incidence of new patients is slowly but steadily increasing, from 107 to 131 pat/pmp; although there have been some variations from one year to Spain England Holland Spain Italy Germany Portugal Taiwan Japan USA 0 50 100 150 200 250 300 95 100 131 130 170 200 252 310 337 350 USA Italy Holland Canada United Kingdom New Zeeland Mexico 0 0.1 0.2 0.3 0.4 PD 0.5 0.6 HD 0.7 0.8 0.9 1 Fig. 9.--Comparative international incidence. Fig. 11.--International comparison of dialysis modality in prevalent patients. 127 M. CEBALLOS y cols. 30 25 20 15 10 5 0 Spain DOPPS Japan USA % 13,5 16 9 24 Fig. 12.--Comparative mortality for dialysis. another it seems that a plateau have been reached in recent years after a steep increase in the first half of the 1990s, although the data gathering methodology changed in 1996. Until that date, the annual report was elaborated from the EDTA Registry, but after its failure and the creation of the autonomic registries, the report is elaborated from the data given by the later and, thus, the data are more accurate. An issue that is confirmed every year is the big difference in the incidence rate between the autonomous communities, the difference in the incidence between different countries or regions, which may be due to several reasons; the first one might be that a real difference would exist between nephropathies that lead to ESCRF, since the most important cause is diabetes and a higher frequency in diabetic nephropathy would lead to a higher incidence of end-stage renal disease. Indeed, within Spain, the Canary Islands have one of the highest percentages worldwide of incident diabetic patients, which reached 48% in 20023. However, other communities with a high incidence rate, such as Catalonia and the Community of Valencia have respectively 21% and 17% of incident diabetic patients. In some countries, the racial distribution may explain the differences, since, at least in the USA, Afroamericans have an incidence of ESCRF four-fold the one in whites, but in Spain, to date, there are no such racial differences between communities, the Health System is homogeneous, there are no economic restrictions to enter treatment or great differences in medical practice in relation to acceptance of patients to treatment, and there is no lack of dialysis units; therefore, this is an issue for which an evident answer does not exist and that deserves a profound epidemiological study. Although incidence is not one of the highest in Europe, it is the contrary for prevalence, and this may due to a rather low mortality rate for dialysis and a very high transplantation rate, with a high 128 number of transplanted prevalent patients that, in turn, have a much lower mortality. Since mortality is stable since 1996, the prevalence increase is due to the increase in incidence, both curves being parallel. Renal disease mainly affects patients with advanced age, thus, population aging explains the increase in incidence and influences in part the etiology of renal failure, and so vascular nephropathy is the second most frequent cause. It is remarkable that for an important number of patients that start on RRT the etiology of their renal failure is unknown; this may indicate that still a high number of patients reach the nephrologist in an advanced stage of their disease, although in many cases the diagnosis of vascular nephropathy is by exclusion and it may be possible that some cases that are considered of unknown etiology may be of vascular origin; in fact, it is in the older group of patients where the percentage of unknown etiology is higher. In the population group older than 75 years, the incidence rate is somewhat lower, which may be likely due to the fact that some patients will not start treatment because of comorbilities. In relation to diabetes, although it is the first known cause, it does not reach the proportion seen in other countries2. It is also hard to explain the great differences in utilization of dialysis modalities, which varies a lot for peritoneal dialysis with percentages that range from 0 to 24%. In general, there is a low rate of patients on peritoneal dialysis. Regional differences hide, in turn, interregional differences since it is known, although not studied in this report, that there are important variations from one hospital to another within the same city. The only explanation seems to be nephrologists' preferences in regards to one or the other technique since there is not a conditioning economic factor, contrary to what happens in other countries. These differences replicate worldwide where countries with similar economic and health service status have a rather different frequency in modality utilization. In one study done worlwide7 comprising 120 countries, hemodialysis was the modality used in 69% of patients, peritoneal dialysis in 8.5% and renal transplantation in 23%. Life expectancy for population on dialysis is lower than that of the general population, with a high crude mortality rate, much higher than that of the general population, which is 1%4, although both populations are different since they have different mean age, which is 30 years for the Spanish population; so that, in order to be comparable both rates would have to be adjusted at least for age and gender. Although we have observed that cardiovascular diseases are the most important cause of death in pa- SPANISH DIALYSIS AND RENAL TRANSPLANTATION REGISTRY-2002 tients on RRT, and it is so admitted worldwide, this proportion is similar to that of the general population, although death risk is higher due to the higher global mortality rate in patients on renal replacement therapy. Infectious causes are the second most frequent cause for the three treatment modalities and there are remarkable differences with regards to neoplasms, which are a more frequent death cause in transplanted patients. The transplantation rate remains very high, as it is for the last several years, which explains that almost 50% of prevalent patients have transplantation and in some communities this figure is exceeded. This report has limitations derived from the methodology, since a limited number of data is gathered and these are not individual but aggregate data; the only adjustment that can be done is for age, and only in large groups. However, with the available data it is possible to draw valuable conclusions on the epidemiology of renal disease, utilization of the different treatment modalities, and global mortality. Data quality control is the responsibility of the different registries, although by elaborating the report we are able to exert an indirect control through comparison of the data from previous years and, in this sense, the data are coherent with barely noticeable annual variations. In summary, we can affirm that, since 1996, there has been a moderate and parallel increase in incidence and prevalence; diabetes is the first known cause of ESCRF; there are important regional differences in incidence and type of prevalent treatment; the number of transplantations is very high with a tendency to become stable; mortality rates are similar for hemodialysis and peritoneal dialysis, and remain stable for the last years and lower than those of previous registries. Finally, we must point out that the percentage of the Spanish population covered by this report is increasingly higher and it would be desirable that both health authorities and the nephrology community become aware of the registries usefulness and we will finally get available the situation for Spain as a whole. REFERENCES 1. Naya MT, Garrido G, Cuende N, Cañón J, Miranda B: Donación y trasplante renal en España durante el 2002. Nefrología. 23: 5, 2003. 2. ERA-EDTA Registry: ERA-EDTA Registry 2002 Annual Report. Academic Medical Center, Amsterdam, The Netherlands, May 2004. 3. US Renal Data System. USRDS 2002 Atlas of End-Stage Renal Disease in the United States, National Institutes of Health. National Institute of Diabetes and Digestive and Kidney Disease, Bethesda, MD, 2002. http://www.usrds.org. http:// www.usrds.org. Consultado el 12 de septiembre de 2004. http://www.usrds.org. 4. Instituto Nacional de Estadística.http://www.ine.es/inebase/ cg1/axi. Consultado el 12 de septiembre de 2004. 5. López Revuelta K, Saracho R, García López F, Gentil MA, Castro P, Castilla J, Gutiérrez JA, Martín-Martínez E, Alonso R, Bernabéu R, Munar MA, Lorenzo V, Vega N, Escallada R, Sierra T, Lara M, Estébanez C, Clèries C, Vela E, Tallón S, García-Blasco MJ, Zurriaga O, Vázquez C, Sánchez-Casajús A, Torralbo A, Rodado R, Genovés A, Ripoll J, Asín JL, Magaz A, Aranzábal J: Informe de diálisis y trasplante año 2001 de la Sociedad Española de Nefrología y Registros Autonómicos. Nefrología 28: 21-33, 2004. 6. Rayner HC, Pisoni RL, Bommer J, Canaud B, Hecking E, Locatelli F, Piera L, Bragg-Gresham JL, Feldman H, Goodkin DA, Wolfe RA, Held PJ, Port FK: Mortality and hospitalisation in haemodialysis patients in five European countries: results from the Dialysis Outcomes and Practice Patterns Study (DOPPS). Nephrol Dialysis Transplantation 19(1): 108-120, 2004. 7. Moelle E, Gioberge S, Brown G: ESRD patients in 2001: global overview of patients, treatment modalities and development trends. Nephrol Dial Transplant 7: 2071-2076, 2002. 129