Tendência da mortalidade por câncer de pulmão, traqueia e brônquios, segundo período e coorte, no estado de Minas Gerais, 1980 a 2010

Abstract

Analysis of mortality rates for cancer of the lung, trachea, and bronchi according to period and cohort effects is relevant due to changes in behavior related to smoking, whose prevalence has been changing over the years, by sex and age group. The aim of the study was to analyze trends in mortality from lung, tracheal, and bronchial cancer in the State of Minas Gerais, from 1980 to 2010, and compare the specific mortality rates and time series behavior, by age and gender subgroup, according to birth cohorts. This is an ecological study of time series using secondary data on deaths from cancer of the lung, trachea, and bronchi, comprised of individuals over 30 years of age. Data from the Mortality Information System and the Brazilian Institute of Geography and Statistics were used. Correction for underreporting was performed by redistributing deaths from poorly-defined causes. Data were evaluated by taking into account the period and the cohort, across age subgroups in five-year segments. Mortality rates for the selected causes were adjusted by age group, according to the direct method standardization technique, using the population of Minas Gerais, from the year 2010, as the standard. The period effect indicated a significantly increasing mortality trend in females and stability in males. The cohort and age group analysis was performed by means of the specific mortality rate indicator and the ratio of the rates, depicted via trend charts and tables. The cohort effect showed a convergence of rates between the two sexes, with a greater increase in the rates for females. Mortality rates for both sexes increased with age, but this effect was greater for females than for males. The evaluation of specific mortality rates, by age group, showed a reduction in mortality rates in males between 30 and 54 years. Among women, there was an increase in the specific rates for all age groups above 35 years. The results suggest that the impact of the changes in behavior has been "negative" for females. Moreover, the fact that cohort analyses were performed in this study made it possible to show more clearly the different stages of the tobacco epidemic that men and women of Minas Gerais undergo. The variation in mortality rates between the sexes may be contributing to the reduction of gender-related differences in this state. We emphasize the need for further actions to control smoking, taking into account the differences in behavior between the sexes, in order to reduce the prevalence of lung, tracheal, and bronchial cancer. The differences in trends between the sexes raise the need to better understand other gender-related issues that may influence mortality rates.