Vacinação contra a influenza : redução na hospitalização e óbitos por doença respiratória em idosos

Abstract

The aging of the population has led to the search for interventions that may reduce health problems or prevent the complications of chronic conditions already existent. In the prevention field, the vaccines against influenza are highlighted, because respiratory diseases are great causes of illness and/or death in the senior population. In spite of the fact that vaccination against flu has started in Brazil in 1999, and is dispensed to individuals over 60 years of age in annual campaigns, the studies that evaluate the impact of this intervention are still scarce. Thus, this study had the purpose to evaluate the coverage of the vaccine against flu to the elderly in Paraná State and, the impact of such immunization in the morbidity and mortality caused by diseases of the respiratory system in the population over 60 years of age among t he health macro-regions of the State. The study was accomplished using information obtained in four sources of data: Hospital Data System of the Public Health Services, Data System of Mortality, Data System of the National Program of Immunizations and, Brazilian Institute of Geography and Statistics, all made available by the Department of Computer Science of the Public Health Services. The immunization coverage and the mortality were studied in the period from 1999 to 2005 and in the period from 1995 to 2004, respectively. For the determination of the impact of the vaccination in the hospitalizations the following indicators were approached: a) hospitalization rate for selected respiratory diseases / 1,000 of senior inhabitants, b) proportion of the respiratory diseases selected among the total of hospitalizations, c) relation between the selected respiratory diseases and hospital beds available. To determine the death impacts caused by respiratory diseases the coefficient of general mortality in senior people was used. For data treatment the Analysis of Variance, Tuckey Test, and Graph of Residues were used. The results revealed that in general, the vaccination coverage among the elderly of Paraná State was above the average of 70% predicted by the Ministry of Health. The macro-regions 1, 2 and 3 did not reach the goal expected on the year 2000 and the macro-region 2 did not reach its goal in the years 2001 and 2002 either. A statistically significant decrease was observed in hospitalization of elder people with respiratory diseases, after the vaccine intervention. The risk of hospitalization for respiratory diseases was 1.09 times (8.36%) greater among men. When comparing individuals over 80, with the ones between 60 and 64 years of age, the risk of hospitalization for respiratory diseases was shown to be 3.2 times greater. Such risk decreases with the age, being 2.84 times greater among the seniors of the group 75-79 years old, 2.18 times greater for the ones 70-74 years old, and 1.47 times greater among the ones 65-69 years old. The hospitalizations for respiratory diseases were seasonal, with the major incidence from June to October, which corresponds to the season of rain and low temperatures in the State of Paraná. The macro-regions that presented better index of hospital morbidity were in decreasing order, the ones of number 1, 2, 6, 5, 4 and 3. As for the mortality it was observed that the risk of dying from any of the causes was 1.31 times (16.28%) greater, among the male seniors. For those over 80 years of age, the coefficient of general mortality was 7.21 times greater than the group of 60- 64 years old. Among the other age groups this risk was 3.74 times (75-79 yrs), 2.37 times (70-74 yrs) and 1.54 times greater (65-69 yrs) when compared to the age group that presented smaller coefficient of general mortality (60-64 yrs). The risk of dying from respiratory diseases decreased significantly, going from the 3rd to 4th cause of death according to groups of causes and, this phenomenon seems to be associated to the vaccine intervention. The health macro-regions with better mortality rate were the macro-regions 3 and 5, followed by macro-regions 6, 1, 2 and 4, respectively. The proof of the positive impact of the vaccination against flu in the senior population, the existence of differences in the hospitalization profile and on deaths caused by related diseases in the State of Paraná, can contribute to redirect the strategies that promote the seniors' adhesion to the vaccination campaigns taking into account the particularities of each area. New studies describing this phenomenon among the areas of Brazil are necessary.