Infant mortality in the Brazilian countryside: a proposal to overcome epidemiological and demographic invisibility

The study aimed to compare two concepts of rurality, one proposed by the Brazilian Institute of Geography and Statistics (IBGE) and the other by the World Bank, to determine which is better fitted to the territory's reality, besides analyzing the infant mortality profile of rural municipalities (counties) in the state of Paraiba, Brazil, according to the best criterion for rurality. This was an observational epidemiological study conducted in the state of Paraiba. The method for analyzing rural/urban typologies was based on data mining, using the Apriori algorithm of association. Infant mortality was analyzed with descriptive statistics. The data were obtained from the Mortality Information System of the Brazilian Ministry of Health, from 2007 to 2016, and municipal indicators were from IBGE. The World Bank definition of rurality showed kappa = 0.337, compared to the IBGE definition, with kappa = 0.616. Among the 223 municipalities that were analyzed, the World Bank classified 130 (65.66%) correctly, and the IBGE 183 (82.06%). The predominant epidemiological profile of infant mortality in rural municipalities in Paraiba state was male gender (57.4%), brown skin color (61.1%), age from 0 to 7 days (52.4%), low birthweight (44%), and gestational age less than 37 weeks (43.2%). Underlying cause of death was classified as avoidable death via interventions by the Brazilian Unified National Health System (65.2%). The urban/rural typology adopted by the IBGE was better than the World Bank at classifying the municipalities in Paraiba state. This classification allowed studying the infant mortality profile in rural municipalities, which was similar to the overall profile, except for maternal schooling.