The influence of the Municipal Human Development Index compared to maternal education on infant mortality: a retrospective cohort study in the extreme south of Brazil

Abstract

Background: Infant mortality is considered an important and sensitive health indicator in several countries, especially in underdeveloped and developing countries. Most of the factors influencing infant mortality are interrelated and are the result of social issues. Thus, this study investigated the influence of the Municipal Human Development Index (MHDI) of the residence macro-region compared to maternal education on infant mortality in a capital city in the extreme south of Brazil. Methods: It is a retrospective cohort study with data on births and deaths for the period of 2000-2017. The association between the independent variables and the outcome was done by bivariate analysis through simple Poisson regression. Those with significant association (p<0.001) were used in a multiple Poisson regression for robust variances - adjusted model. Results: The study included 311361 children, of whom 2271 died. Maternal education, individually and jointly analyzed with the MHDI, showed association with the outcome of infant death in the first year of life, particularly for children of mothers with lower maternal education (p<0.001). In relation to other related factors, maternal age; number of Prenatal Care Consultations; gestational age, weight, gender and Apgar Index (5th minute) of the newborn showed association with IM (p<0.001). Conclusions: The lower the HDI classification of the macro-region, the worse were the socioeconomic and demographic conditions, but the results presumably indicated that an individual maternal characteristic supplants the environment in which the family resides as a factor of protection to infant mortality, reinforcing the relevance of maternal education as a social determinant in health.