Renal replacement therapy in Latin America

Abstract

Renal replacement therapy in Latin America. The Latin American Society of Nephrology and Hypertension (SLANH) Dialysis and Renal Transplantation Registry was created in October 1991 as a multinational, mainly voluntary registry. Annual data reports on the incidence, prevalence and outcome of renal replacement therapy (RRT) in the region have been issued. The RRT prevalence increased from 123 per million population (pmp) in 1992 to 180 pmp in 1997, and the acceptance rate was 57 pmp in 1997. Among incident patients, 32.8% were older than 65 years and 24% had diabetic nephropathy. Mortality rate in dialysis patients was 152 deaths per 1000 patient-years at risk. The low acceptance rate is mainly a consequence of economic and health care system difficulties in Latin American countries. A large number of patients in this region do not reach RRT due to restricted availability and difficulties in referral. There are important demographic, socioeconomic, acceptance availabilities, and questionnaire response rate heterogeneity among Latin American countries. Because of this heterogeneity, it is very difficult to compare data obtained from different countries of this region of the world. To overcome this difficulty is the critical challenge for the future activity of the SLANH Registry. Renal replacement therapy in Latin America. The Latin American Society of Nephrology and Hypertension (SLANH) Dialysis and Renal Transplantation Registry was created in October 1991 as a multinational, mainly voluntary registry. Annual data reports on the incidence, prevalence and outcome of renal replacement therapy (RRT) in the region have been issued. The RRT prevalence increased from 123 per million population (pmp) in 1992 to 180 pmp in 1997, and the acceptance rate was 57 pmp in 1997. Among incident patients, 32.8% were older than 65 years and 24% had diabetic nephropathy. Mortality rate in dialysis patients was 152 deaths per 1000 patient-years at risk. The low acceptance rate is mainly a consequence of economic and health care system difficulties in Latin American countries. A large number of patients in this region do not reach RRT due to restricted availability and difficulties in referral. There are important demographic, socioeconomic, acceptance availabilities, and questionnaire response rate heterogeneity among Latin American countries. Because of this heterogeneity, it is very difficult to compare data obtained from different countries of this region of the world. To overcome this difficulty is the critical challenge for the future activity of the SLANH Registry. Latin America is a heterogeneous region with very important differences in social and economic status. The gross national product (GNP) ranges from $900 per capita per year in Haiti to $26,000 in Puerto Rico, and the Human Development Index from 0.340 to 0.8931Programa de las Naciones Unidas para el Desarrollo Informe sobre Desarrollo Humano, 1998. Ediciones Mundi-Prensa, Madrid1998Google Scholar. The Latin American Society of Nephrology and Hypertension (SLANH) comprises 21 countries with a total population of 491 million inhabitants Table 12Centro Latinoamericano de Demografía Boletín Demográfico. Santiago, Chile, Celade1989Google Scholar.Table 1Prevalence of renal replacement therapy in Latin AmericaPrevalenceTotal population millionsaMid year estimation–1997. Demographic Bulletin–CELADE2GNPbAbbreviations are: HD, hemodialysis; GNP, gross national product; PD, peritoneal dialysis; RT, renal transplant; pmp, per million population (US)cHuman Development IndexHDIc,Human Development IndexdHuman Development Report 1998. UN Program for Development1HDPDRTTotal pmpbAbbreviations are: HD, hemodialysis; GNP, gross national product; PD, peritoneal dialysis; RT, renal transplant; pmp, per million populationArgentina35.4184890.88812000700–359Bolivia7.9226170.59379552320.7Brazil167.0559280.8092546843323600200Chile14.6999300.89350771581300445Colombia36.2063470.850160020001200133Costa Rica3.5859690.8897430454156Cuba11.1931000.729755145597134Ecuador11.9446020.76730550–30El Salvador6.0326100.6041051608157Guatemala11.2436820.615147125–24Haiti7.489170.340––––Honduras5.9819770.57376113–32Mexico97.2467690.855163613452–155Nicaragua4.7318370.547––––Panama2.7262580.8682023460109Paraguay5.2235830.70738007587Peru24.6939400.729152829–63Puerto Rico3.82269772321684285861R. Dominicana8.1039230.879395––52Uruguay3.2268540.885182788239669Venezuela22.7880900.8603000500870192Total491.2356975226558807180a Mid year estimation–1997. Demographic Bulletin–CELADE2Centro Latinoamericano de Demografía Boletín Demográfico. Santiago, Chile, Celade1989Google Scholarb Abbreviations are: HD, hemodialysis; GNP, gross national product; PD, peritoneal dialysis; RT, renal transplant; pmp, per million populationc Human Development Indexd Human Development Report 1998. UN Program for Development1Programa de las Naciones Unidas para el Desarrollo Informe sobre Desarrollo Humano, 1998. Ediciones Mundi-Prensa, Madrid1998Google Scholar Open table in a new tab The SLANH Dialysis and Renal Transplantation Registry was created in October 1991, and it is operated by a Coordinating Committee located in Montevideo, Uruguay. The primary objectives, general organization, and financing of the Registry were stated during the first meeting of National Representatives held in Montevideo in 19943Mazzuchi N. Schwedt E. Fernandez J.M. Cusumano A.M. Ancao M.S. Poblete H. Saldana-Arevalo M. Espinosa N.R. Centurion C. Castillo H. Gonzalez F. Milanes C.L. Infante M. Ariza M. Latin American Registry of Dialysis and Renal Transplantation: 1993 annual dialysis data report.Nephrol Dial Transplant. 1997; 12: 2521-2527Crossref PubMed Scopus (44) Google Scholar. Definitions, data collection, and statistical methodology applied have been previously published3Mazzuchi N. Schwedt E. Fernandez J.M. Cusumano A.M. Ancao M.S. Poblete H. Saldana-Arevalo M. Espinosa N.R. Centurion C. Castillo H. Gonzalez F. Milanes C.L. Infante M. Ariza M. Latin American Registry of Dialysis and Renal Transplantation: 1993 annual dialysis data report.Nephrol Dial Transplant. 1997; 12: 2521-2527Crossref PubMed Scopus (44) Google Scholar,4Registro Latino Americano de Diálisis y Transplante Renal-Año 1998.Nefrología Latinoam. 1998; 5: 104-159Google Scholar. At the request of the Coordinating Committee, the National Registry of each local society of nephrology provides data to the primary database. Most of these national registries are voluntary. Data are collected in three types of questionnaires: patient, center and country questionnaire. The country questionnaire includes renal replacement therapy (RRT) modality, incidence and prevalence rates. This database is updated every year. The yearly evolution of the incidence and prevalence rates of the registered end-stage renal disease (ESRD) dialysis patients is presented in Figure 1. The number of registered patients increased during the first few years of the registry activity. Afterwards it decreased abruptly, and now it seems to be growing gradually. Since the creation of the registry, annual data reports on the incidence, prevalence and outcome of RRT in the region have been issued3Mazzuchi N. Schwedt E. Fernandez J.M. Cusumano A.M. Ancao M.S. Poblete H. Saldana-Arevalo M. Espinosa N.R. Centurion C. Castillo H. Gonzalez F. Milanes C.L. Infante M. Ariza M. Latin American Registry of Dialysis and Renal Transplantation: 1993 annual dialysis data report.Nephrol Dial Transplant. 1997; 12: 2521-2527Crossref PubMed Scopus (44) Google Scholar, 4Registro Latino Americano de Diálisis y Transplante Renal-Año 1998.Nefrología Latinoam. 1998; 5: 104-159Google Scholar, 5Mazzuchi N. Fernández J.M. Schwedt E. Celia E. Cusumano A.M. Soto Ríos K. Silva Ançao M. Poblete H. Espinosa N.R. Castillo H. Milanés C.L. Ardilla M. Ariza M. Registro latinoamericano de diálisis y trasplante renal. Informe de diálisis, Año 1991.Nefrología Latinoam. 1994; 1: 89-99Google Scholar, 6Mazzuchi N. Schwedt E. Fernández-Cean J. Cusumano A.M. Soto K. Silva Ançao M. Poblete H. Espinosa N. Franco S. Castillo H. González F. Milanés C.L. Ardilla M. Ariza M. Registro latinoamericano de diálisis y trasplante renal. Año 1992 Parte I Diálisis.Nefrología Latinoam. 1995; 2: 309-331Google Scholar, 7Mazzuchi N. Schwedt E. Fernández Cean J.M. Registro latinoamericano de diálisis y trasplante. Informe 1993.Nefrología Latinoam. 1996; 3: 320-357Google Scholar, 8González-Martínez F. Agost-Carreño C. Silva-Ancao M. Elgueta S. Cerdas-Calderon M. Almaguer M. Garces G. Saldana-Arevalo M. Castellano P. Perez-Guardia E. Centurion C. Castillo H. Santiago-Delpin S. Lafontaine H. Rodriguez-Juanico L. Milanes C. Mazzuchi N. 1993 renal transplantation annual data report.Transplant Proc. 1997; 29: 257-260Abstract Full Text PDF PubMed Scopus (5) Google Scholar, 9Registro Latinoamericano de Diálisis y Trasplante Renal Informe de Diálisis, año 1994.Nefrología Latinoam. 1997; 4: 136-200Google Scholar, 10Schwedt E. Fernández J. González F. Mazzuchi N. End-stage renal disease in Latin America.Nephrology. 1998; 4: S81-S82Crossref Scopus (2) Google Scholar. The time course of RRT prevalence from 1992 to 1997 showed a gradual increase Figure 2. While the overall response rate to the dialysis patient questionnaire was 22% in 1997 Figure 3, five countries (Chile, Panama, Puerto Rico, Dominican Republic and Uruguay) sent 100% of their patient data. According to the country questionnaires there were 88,437 patients on RRT in Latin America, or 180 per million population (pmp). Of these patients, 64% were on hemodialysis (HD), 26% were on peritoneal dialysis (PD) and 10% were living with a transplanted kidney Table 1. The prevalence of patients on dialysis in 1997 was 162 pmp: 72% were on HD and 28% on PD (Table 1 and Figure 4). The prevalence of dialysis therapy was very different from country to country: Puerto Rico had the highest and Bolivia the lowest prevalence rate. The percentage of patients on PD was very high in Mexico, but very low in Chile. The mean age of dialysis patients was 52.5 (± 17.4) years, and 28.3% of the patients were older than 65 years. Fifty-eight percent of the patients were male. The most frequent types of nephropathy were vascular nephropathy (21.1%), glomerulonephritis (18.4%), and diabetic nephropathy (16.1%). The overall acceptance rate in Latin America was 57 pmp (20 patients) in 1997, but the acceptance rates for each country varied widely. Argentina, Puerto Rico, and Uruguay had an incidence rate over 100 patients pmp, whereas Brazil, Costa Rica, Cuba, Chile, and the Dominican Republic had an incidence rate between 50 and 100 pmp. In other Latin American countries the acceptance rate was less than 50 pmp. Patients with ESRD from Ecuador, Guatemala and Mexico were accepted to RRT, but the incidence rates were not reported. The ESRD incidence by country is presented in Figure 5. Epidemiological reasons could partially explain these differences, but these numbers primarily represent economic restrictions in the health care system. A large number of patients in Latin America do not reach RRT due to restricted acceptance and availability of these therapies, and difficulty in making referrals. The unfortunate conclusion is that a substantial number of ESRD patients die each year without RRT in Latin America. The mean age of the incident patients averaged 54.4 (±17.8) years and 32.8% of the patients were older than 65 years. Fifty-eight percent of the patients were male. The leading causes of ESRD were diabetic (24.4%), vascular (19.5%), and glomerular (12.1%) nephropathy. The proportion of diabetic nephropathy among incident patients Figure 6 ranged between 16% in Uruguay to 57% in Puerto Rico. It has been claimed that this variation in diabetic percentage is related to incidence differences. For example, countries with a high incidence of ESRD, such as the United States, Japan, and Puerto Rico, are the same countries with a high percentage of sicker patients and therefore, a high acceptance rate of those with diabetic nephropathy11US Renal Data System USRDS 1998 Annual Data Report. National Institutes of Health National Institute of Diabetes, Digestive, and Kidney Diseases, Bethesda, MD1998Google Scholar. This opinion does not seem to be supported if the incidence of ESRD in Uruguay and Puerto Rico is compared with the percentage of incident patients with diabetes. Both countries have the highest incidence in Latin America Figure 5, but although Puerto Rico has the highest percentage of patients with diabetes in Latin America, Uruguay has the lowest Figure 6. Differences in the prevalence of diabetic disease in the general population and differences in the care of diabetic patients during the period prior to ESRD could also explain these rates. During the decade 1987 to 1997, both the number of transplants per year and the cumulative number of transplanted kidneys gradually increased Figure 7.Figure 7Transplants registered in Latin America from 1992 to 1997. Symbols are: (□), performed during the year; (▪), cumulative.View Large Image Figure ViewerDownload (PPT) The adjusted hospitalization time was 7.83 days/patient-year Table 2. The standard was the Latin American 1991 to 1994 hospitalization timetable9Registro Latinoamericano de Diálisis y Trasplante Renal Informe de Diálisis, año 1994.Nefrología Latinoam. 1997; 4: 136-200Google Scholar. Diabetics had the highest value (10.5 days/patient-year). The mortality rate in dialysis patients was 152 deaths per 1000 patient-years at risk. Mortality rates were greater for HD (157 deaths per 1000 patient-years at risk) than PD patients (108 deaths per 1000 patient-years at risk).Table 2Standardized mortality rate and standardized time of hospitalization rateCause of ESRDStandardized mortality rateaStandard: 1991–1994 Latin American Registry Mortality Table (deaths per 1000 patient-years)Standardized time of hospitalization (days per patient-year)bStandard: 1991–1994 Latin American Registry Hospitalization Time TableGlomerulonephritis85.36.96Hypertension152.58.18Diabetes246.210.50Other143.17.87Total139.37.83a Standard: 1991–1994 Latin American Registry Mortality Tableb Standard: 1991–1994 Latin American Registry Hospitalization Time Table Open table in a new tab Mortality was adjusted by age and kidney disease, using the 1991 to 1994 Latin American dialysis mortality table as the standard9Registro Latinoamericano de Diálisis y Trasplante Renal Informe de Diálisis, año 1994.Nefrología Latinoam. 1997; 4: 136-200Google Scholar. Four major categories of ESRD etiologies were considered: diabetes, hypertension, glomerulonephritis, and other disease. Age groups were defined using five-year intervals, except the younger-than-15-years and older-than-85-years age brackets. The adjusted mortality rate was 139 deaths/1000 patients-years at risk Table 2. Patients with glomerulonephritis had the lowest mortality rate (85 per 1000 patient-years) and the highest mortality was observed in patients with diabetic renal disease. The SLANH Registry has incorporated data from several national RRT registries for the last decade, and its analysis and subsequent publications have contributed to a greater understanding of the epidemiology of renal disease and RRT in Latin America. In the near future, we hope that this analysis and other published information will help Latin American nephrologists to propose ESRD prevention and treatment programs to their national and regional health authorities. While these efforts are laudable, we must note that the Latin American registry has limitations related to differences in the following areas. In countries like Brazil, there are important racial differences and the majority of the population is of mixed race. In contrast, other countries such as Peru have a very high proportion of aboriginal populations, and still other countries, such as Uruguay, have racially homogeneous populations, with few aboriginal people. Considerable differences in age distribution are also observed. A wide variation in the values of gross national product and Human Development Index is observed among Latin American countries. These rate differences directly affect the amount and quality of healthcare. Differences in annual total health expenditures are very large in this diverse population. The low prevalence of RRT in Latin America is due to the fact that in many countries of the region, acceptance to this treatment is restricted. In other countries, all patients are accepted without restriction. There are also differences in referral patterns. Only five countries provided a 100% response for their patients' questionnaire. Because of the heterogeneity in the above factors, it is very difficult to compare data obtained from different countries of Latin America as well as with other countries or regions of the world. The critical challenge for the future activity of the SLANH Registry is how to overcome these difficulties.