CUBAN MEDICAL LITERATURE

Effect of Primary Health Care on Prevention
of Chronic Kidney Disease in Cuba

By Miguel Almaguer López, MD

INTRODUCTION

Chronic kidney disease (CKD) is an important and increasing health problem in the world and also in Cuba. Epidemiologic research has demonstrated that there is an increase in incidence, prevalence and complications of this disease. Its progression towards end-stage renal disease (ESRD) has caused a yearly exponential rise in new patients requiring renal replacement, such as dialysis or renal transplant, from 7% to 10%, depending on the country.[1] In addition to the ethic, economic, and social effects on health services and society, this creates significant human suffering for the patient and his family.

There is growing evidence regarding effective interventions for preventing CKD and its progression, which could potentially bring about a decrease in the complications, the need for dialysis or renal transplant, and premature death.

In Cuba, measures are being introduced - mainly at the primary health care level - with the purpose of reducing CKD and its complications in the general population.

NATIONAL HEALTH SYSTEM AND PRIMARY HEALTH CARE

Cuba has a population of 11,250,979 inhabitants and a land surface of 110,922-sq km. The country has a unique public health system, which is free and accessible to the entire population. It includes 67,079 doctors, 31,059 of whom are dedicated to primary health care.[2] Primary health care includes 444 territories called health areas, each one having an outpatient clinic and a variable number of family doctor’s offices depending on its total population. Each family doctor treats an average population of 120 families, or around 600 people.

Some of the country’s main health indicators are: an infant mortality rate of 6.5 deaths per 1000 live births [rate for 2004: 5.8 X 1000, eds]; 99.2% of the children are alive at 5 years of age and 95% of children receive a complete vaccination schedule against thirteen preventable diseases [rate for 2004: 98%, eds]. Life expectancy is over 75 years for both sexes and only 1% of total deaths are due to infectious diseases. The main causes of death are cardiovascular diseases, cancer, cerebrovascular diseases and diabetes mellitus, among other non-communicable diseases.[2] CKD appears in this public health context.

CHRONIC KIDNEY DISEASE BURDEN

The first national primary CKD mortality study was carried out from 1970-1972. It was based on death certificates and autopsies performed in hospitals showing 89% of diagnoses confirmed through anatomical pathology. A death rate of 101 to 132 per million inhabitants was found.[3] In 1991, a national study of multiple death causes from chronic renal failure was carried out. It was based on death certificates, which defined the main causes of CKD as: diabetes mellitus 30.5%; arterial hypertension 19.8%; urological causes 9.8%; glomerulopathies 7.3%; and congenital, 5%.[4]

Several population-based epidemiological studies during the 1984-1992 period have described a prevalence of chronic renal failure of 1.1 to 3.5 patients per 1000 inhabitants.[5,6,7]

A population-based screening and follow-up study with intervention during nine years of primary health care in 627 patients with glomerular filtration rates (GFR) <70 ml/min, showed a change in the distribution of patients according to stage of CKD. At the beginning of the study, 37% of the patients had GFR of 70-30 ml/min and by the end, it rose to 76%.[5]

NATIONAL PROGRAM FOR PREVENTION OF CHRONIC KIDNEY DISEASE

In 1996, the Ministry of Public Health approved the National Program for the Prevention of CKD,[8] which forms part of the National Program for the Prevention of Non-Communicable Diseases.

The objectives are a reduction of CKD risk factors in the general population, identification and monitoring of individuals at increased risk for developing CKD, early CKD diagnosis and effective treatment to delay its progression. Additional objectives include patient rehabilitation and improvement in quality of life, and establishment of a CKD surveillance system at the primary health care level.

The program considers interventions at the level of general population and among individuals; the cornerstone of this strategy is the family doctor interacting with nephrologists at the primary health care level (see Figure 1).

Figure1: National Program for the Prevention of Chronic Kidney Disease: Preventive Actions, Cuba.

PROCEDURE FOR IMPLEMENTING THE PROGRAM

Several steps have been taken for the progressive implementation of the program. The main ones are described below.

The first step, already described in its initial phases, is the epidemiological study of the disease burden, its patterns, distribution and trends, and a small-scale trial of the interventions.

A second important step is the training of the health team performing the interventions at the primary health care level. Improving the knowledge base and competencies of the health team, guided by the goals of the program, is essential.

Nephrology residents’ curriculum includes a subject called “Community-Based Preventive Nephrology.” Family doctors receive a 40-hour course on “Prevention, Diagnosis and Treatment of Chronic Kidney Disease,” taught by nephrologists at outpatient clinics (primary health care). Furthermore, there is a longer 400-hour course on “Preventive Nephrology” for family doctors selected by each clinic.

A third step is redirecting services for nephrology patients towards primary care institutions, bringing them closer to the community.

A fourth step is the inclusion of CKD in the continuous assessment and risk evaluation (CARE) system carried out by family doctors and nurses (registry, risk evaluation, treatment, vaccination against hepatitis B virus and follow-up with the patients by family doctors). Patients with diabetes mellitus and high blood pressure (HBP), both substantial in groups with increased CKD risk, are also included in the CARE system, contributing to better monitoring of these risk groups.

The CARE system, together with other information sources of the national health system, integrates the CKD surveillance system into primary health care.

Another important step are the actions directed at health promotion in the general population, taken by the health and other sectors, which contribute to CKD prevention.

RESULTS

The CKD Prevention Program, integrated into the Program for the Prevention of Chronic Non-Communicable Diseases, has achieved the following results in accordance with the objectives of the program.

Risk for CKD has been reduced in the general population. Smoking prevalence, 36.8% in 1995, dropped to 31.9% in 2001;[9] control of HBP > 149/90 mmHg in patients with hypertension, 45.2% in 1995, rose to 52.0% in 2001;[9] and low birth weight, 7.9% in 1995, decreased to 5.9% in 2002.[2] Vaccination against hepatitis B (HBV) in initial stage CKD patients at the primary health care level and at the dialysis centers reduced HBV incidence to 0.1% in 2002.[10]

To bring services closer to the community, nephrology departments in the country were increased from 31 to 47, with significant increase in dialysis capacities. Nephrology departments and related primary health care territories were redistributed. New nephrology outpatient services were opened at the primary level. This increases the interaction of nephrologists and family doctors, making the referral and cross referral of CKD patients easier.

CKD prevention training of the primary health care team has improved diagnosis and treatment; 841 family doctors have received the 40-hour course on prevention, diagnosis and treatment of chronic renal disease and 128 family doctors passed the 400-hour preventive nephrology course.

Numbers of known diabetes mellitus and HBP patients registered by family doctors have risen. Prevalence of known diabetic patients was 18.1 per 1000 inh. in 1995 and 27.1 per 1000 inh. by 2002.[11] Prevalence of known patients with chronic renal failure, serum creatinine level ³133 mmol/L (³1.5 mg/dl), also rose from 0.61 per 1000 inh. in 1995 to 0.92 per 1000 inh. in 2002.[11]

The registry and follow-up at the primary health care level of patients with increased CKD risk and patients with chronic renal failure is one of the elements of the CKD surveillance system, which, together with other information sources available in the health system, has enabled knowledge to be gathered on the frequency, distribution patterns and trends of the disease in the population and the program’s actions to be evaluated.

CONCLUSIONS

1. The CKD Prevention Program is being implemented and extended in primary health care centers across the country.
   
   
2. Program actions are carried out in an integrated manner with other programs of the health sector and other sectors.
   
   
3. Nephrology departments have moved closer to the community, improving referral and cross referral of patients with CKD.
   
   
4. There is improved knowledge and competencies among family doctors for carrying out CKD prevention in primary care.
   
   
5. CKD risk in the population has decreased; there is reduced smoking; decreased low weight births; greater control of HBP; and decreased incidence of infections from hepatitis B virus in dialysis patients.
   
   
6. The number of diagnosed patients with diabetes mellitus and HBP registered by family doctors in primary care has increased.
   
   
7. The number of diagnosed patients with chronic renal failure registered by family doctors in primary health care has increased.
   
   
8. Primary health care and the community are the public health tools and ideal social space for carrying out health promotion and the prevention of CKD.

REFERENCES

1. Schena, FP. “Epidemiology of end-stage renal disease. International comparison of renal replacement therapy.” Kidney Int 57 (Suppl 74), 2000: S39-S45.
2. Ministerio de Salud Pública. Dirección Nacional de Estadísticas. “Anuario Año 2002.” La Habana, Cuba, 2002.
3. Almaguer, M; CH Magrans. “Mortalidad por insuficiencia renal crónica. Cuba 1970-72.” Tesis. Instituto de Nefrología. La Habana, Cuba, 1974.
4. Ministerio de Salud Pública. Dirección Nacional de Estadísticas. “Estudio de causas múltiples de muerte de insuficiencia renal crónica.” La Habana, Cuba, 1991.
5. Valdivia, J; M Almaguer; A Garcia; O Benitez; et al. “Aplicación de un programa de nefrología comunitaria en Cuba.” NefrologíaXII (Supl 2): 158.
6. Herrera, R; M Almaguer. “Atención de la insuficiencia renal crónica por el sistema nacional de salud de Cuba.” Primera Conferencia de Consenso: Insuficiencia Renal Crónica, Diálisis y Trasplante. Organización Panamericana de la Salud (OPS). Washington: OPS. Publicación Científica No. 520, p 131-137, 1989.
7. Santa Cruz, P; J Pereira; M Rangel; J Collot; et al. “Prevalencia de insuficiencia renal crónica. Estudio en población abierta. Importancia de la atención primaria de salud.” NefrologíaXII (Supl 2): 158, 1992.
8. Ministerio de Salud Pública. “Programa Nacional de Prevención de la Insuficiencia Renal Crónica.” La Habana, Cuba, 1996.
9. Bonet, M. “I y II Encuesta Nacional de Factores de Riesgo para las Enfermedades No-transmisibles (1995-2001).” Instituto Nacional de Higiene, Epidemiología y Microbiología, La Habana, Cuba. (Datos no publicados).
10. Ministerio de Salud Pública. “Programa Nacional de Hepatitis. Informe Anual Año 2002.” La Habana, Cuba, 2002.
11. Ministerio de Salud Pública. Dirección Nacional de Estadísticas. “Pacientes dispensarizados por diabetes mellitus, hipertensión arterial e insuficiencia renal crónica.” Informe anual Año 2002. La Habana, Cuba, 2002.

This paper was originally published in Academia Nacional de Medicina May 2004, 2(1): 5-10.

THE AUTHOR

Miguel Almaguer López is a nephrologist, epidemiologist, assistant professor, and senior researcher. He heads the Department of Preventive Nephrology at the Institute of Nephrology, Havana.