IJCS | Volume 31, Nº3, May/ June 2018

255 Santos et al. Mortality due to hypertensive diseases in Brazil International Journal of Cardiovascular Sciences. 2018;31(3)250-257 Original Article age groups, the greater the age, the greater the risk of death associated with systemic arterial hypertension. Skin color, taking “whites” as reference group, indicated greater association between hypertensive diseases and mortality in “browns”, and lower association in “blacks”, “yellows”, “indigenous” and in the cases in which this variable was “ignored”. It should be stressed that the total number of “indigenous” and “yellows” added to the “ignored” group corresponded to less than 6%. “Blacks” represented less than 12% of the “brown”, “white” and “black” groups, with the vast majority among the “whites”. Since this is not an ethnical study, but still taking into account that skin color, as stated in the death certificate, has been considered a relevant data in the development of public health policies, the inclusion of this predictor has been less useful in producing racial inferences, than in adjusting this data to the other predictors and establishing iterative algorithms. In addition, it was observed that the models that include the variable “skin color”, compared to the models that exclude this predictor, in addition to presenting predictors with similar IRRs, also achieved convergence in less time and provided lower AIC values, which indicates higher adequacy from a statistical point of view. Taking the southeast region as a reference, due to its highest development level and public policies applied for longer, there was no statistical difference compared to the northeast region, and the other regions presented a lower incidence rate ratio than the southeast Brazil. The predictive model showed that there was no significantly statistical difference in the incidence rate ratio of mortality between the years, when adjusted to the other predictors. Similarly, sex differences had no influence. High-age group, brown skin and southeast and northeast regions were predictors of the greatest mortality during the period under study. Discussion An epidemiological study was carried out based on aggregate data, obtained in population strata. Therefore, in order to avoid the “ecological fallacy”, the applicability of the results cannot be extended to the individual level, to the doctor’s practice level, but only to state, regional and national levels. Since the data were collected from public organizations, which, in turn, came from constant notifications in death certificates, the outline of this article does not include methodological elements able to test their veracity. This also applies to the matter of item selection in the death certificates, which may potentially present differences related to preferences in each state or region to highlight, more or less often, hypertension as a relevant cause of death. The number of deaths associated with hypertensive diseases is related with the increase in age, as can be observed in this study. The impact of this illness tends to aggravate, since the elderly population increases every year, corresponding nowadays to 15% of the world’s population. World projections indicate that this population will continue to increase, and it is estimated that this number may nearly double to 30% by the year 2050. This demands special attention to the development of measures that can help prevent and control hypertensive diseases. 16 In another study, this time about the prevalence of arterial hypertension, the south and southeast regions of Brazil presented higher rates, compared to the other regions: 25% (95% CI: 23.8 - 26.1) and 25% (95% CI: 23.5 - 26.5) , respectively. 17 However, the present study focused on mortality rates associated with hypertensive diseases, and the regions with the highest rates were the northeast and the southeast. Although this issue is beyond the scope of the present research, it is speculated that the discrepancy between higher prevalence and lower mortality in the south could result from more intensive application of therapeutic strategies, both in health care and drug provision. An opposite phenomenon could be observed in a northeastern state. This study showed that the state of Piauí presented, for four consecutive years, the highest mortality rate associated with hypertensive diseases. Nevertheless, a research conducted with elderly people in 2013, in the same state, indicated that the prevalence of SAH in this population is 40.2%, below than expected for that age group, whose prevalence is 68% among the population over 60 years of age. 4,18 Once again, speculatively speaking, but still beyond the scope of this research, this finding could be a result of obstacles to health care and access to medications. These considerations are mainly intended to formulate hypotheses that remain to be analyzed in future research. Death rates associated with hypertensive diseases were higher among the brown population in Brazil,