Trends in mortality from respiratory diseases among the elderly and the influenza vaccine intervention, 1980-2009.

ABSTRACT

OBJECTIVE: To evaluate mortality trends before and after the anti-influenza vaccination campaigns among the elderly in Brazil. METHODS: This was an ecological time-series study of mortality from respiratory diseases among the elderly living in the state of São Paulo, Brazil, in 1980 - 2009. Mortality rates were calculated using death data from the Ministry of Health's Mortality Information System and population data from the Brazilian Institute of Geography and Statistics. Polynomial regression models were used to evaluate mortality trends by sex and age group (60 - 69 years; 70 - 79, and 80 years or older) before and after the beginning of influenza vaccination campaigns. RESULTS: An increase in the respiratory mortality rates was observed in 1980 - 1998, mainly among males. The rate and velocity of the increase was higher among the older age groups. In the years following the vaccine campaigns (1999 - 2009), respiratory mortality rate trends by sex and age stabilized in São Paulo state. CONCLUSIONS: A greater reduction in mortality rates would be observed if vaccinal coverage against influenza were greater and more homogenous. New strategies to increase the uptake of vaccine among the elderly are needed to reach higher coverage levels, especially in municipalities with older and larger populations.