ABC | Volume 110, Nº3, March 2018

Original Article Armstrong et al Urbanization and CV mortality among indigenous populations Arq Bras Cardiol. 2018; 110(3):240-245 investigate the CV mortality profile of indigenous populations during a rapid urbanization process that was largely influenced by governmental infrastructure interventions in the Sao Francisco Valley. For this purpose, we assessed longitudinal data on mortality rates of indigenous and non-indigenous populations in different degrees of urbanization. Methods Study population We assessed data for indigenous mortality in the Sao Francisco Valley, Northeast Brazil (states of Bahia and Pernambuco) between 2007 and 2011, excluding deaths under the age of 30 years. We also assessed the total population in the Sao Francisco Valley according to the Brazilian Institute of Geography and Statistics. The indigenous populations were then divided into two groups according to the degree of urbanization based on previous anthropological evaluations: 9,10 Group 1 - less urbanized tribes (Funi-ô, Pankararu, Kiriri, and Pankarar ); and Group 2 - more urbanized tribes (Tuxá, Truká, and Tumbalalá). We also assessed the mortality for the total population in two important and highly urbanized cities in the Sao Francisco Valley: Juazeiro and Petrolina. The Sao Francisco Valley University Ethics Committee approved this study. Mortality data The Brazilian Indigenous Healthcare Subsystem is currently the responsibility of the Special Secretariat of Indigenous Health, a section of the Ministry of Health, which, since 2007, has implemented a surveillance program regarding mortality. 11,12 Indigenous mortality was assessed from the official records of the Special Secretariat of Indigenous Health. Mortality in the largest cities of the Sao Francisco Valley used the Brazilian Health Ministry registry (DATASUS/TABNET: http://datasus.saude.gov.br/ ). Mortality was classified according to the ICD-10 groups. Cardiovascular mortality was considered if the cause of death was in the ICD-10 CV disease group or if registered as sudden death. Statistical analysis An exploratory analysis was performed to show trends of CV mortality in diverse indigenous populations over time. Trends over the years in CV mortality in adults (≥ 30 y/o) were shown as the percentage of the total deaths at the same age range for total indigenous communities in the Sao Francisco Valley and according to the urbanization group (less urbanized tribes in Group 1, more urbanized tribes in Group 2, and highly urbanized cities). Two Sample Test for Proportions assessed differences in CV mortality rates among indigenous populations. Statistical significance was established if p value < 0.05. STATA 10 was used for computing statistics. Results A total of 75,635 people was registered as indigenous in the Special Indigenous Health Districts of Bahia and Pernambuco. Of these, 25,560 were living in the assessed tribes of the Sao Francisco Valley, mostly in the less urbanized Group 1 tribes (Table 1). There was a tendency for mortality at a younger age between 2010 and 2011 when compared to 2007-2009 (Figure 1). The total of 1,333 deaths was registered for adult indigenous people in the Sao Francisco Valley, 281 deaths (1.8% of the population in 2012) in Group 1 (less urbanized) and 73 deaths (3.7% of the population in 2012) in Group 2 (more urbanized). Between 2007 and 2009, there were 133 deaths in Group 1 and 44 total deaths in Group 2. Between 2009 and 2010, there were 148 total deaths in Group 1 and 29 deaths in Group 2. Table 1 shows the absolute number of deaths in the indigenous people of the Sao Francisco Valley according to the study groups. The proportion of CV mortality has shown consistent increases along time in the assessed populations. Conversely, CV mortality has shown consistent decreases for the largest cities in the Sao Francisco Valley (Figure 2). When the degree of urbanization was considered for the entire period of observation, CV mortality rates were 24% and 37% in Group 1 and Group 2, respectively (p = 0.02). We also found a trend toward a steeper increase in Group 2 CV mortality along time, while Group 1 had nearly stable proportions of CV deaths (Figure 3). Table 1 – Description of indigenous populations in the Sao Francisco River Basin, according to the study groups. Groups Ethnicity Population ¥ Villages Total deaths* Group 1 Funi-ô 4,564 7 58 Pankararu 7,650 27 161 Kiriri 2,185 15 36 Pankararé 1,535 11 26 TOTAL 15,934 281 Group 2 Tuxá 1,665 11 26 Truká 6,741 36 39 Tumbalalá 1,220 8 8 TOTAL 9,626 73 ¥ As registered by the Brazilian Institute of Geography and Statistics for 2012; *Deaths of indigenous people ≥ 30 years old, between 2007 and 2011. 241