Millennium Development Goals: the impact of healthcare interventions and changes in socioeconomic factors and sanitation on under-five mortality in Brazil.

The United Nations approved the Millennium Development Goals (MDGs) in 2000, including Target 4.A, or a two-thirds reduction in under-five mortality by 2015. Brazil reached this target in 2010. The current study aimed to analyze the trend in under-five mortality and the correlation with healthcare, socioeconomic, and sanitation indicators in Brazil's major geographic regions that helped the country meet the MDGs. This was an ecological study using secondary data for Brazil according to Intermediate Urban Linkage Regions (RIAU in Portuguese) from 2001 to 2017. Analyses of tendencies were performed with joinpoint and multiple linear regression models. The study showed a downward trend in the under-five mortality rate during the periods studied, with the largest statistically significant change from 2001 to 2010 (AAPC = -3.95; 95%CI: -4.3; -3.6), the lowest changes from 2011 to 2015 (AAPC = -2.35; 95%CI: -3.7; -1.0), and stabilized rates in 2016 and 2017 (AAPC = -0.07; ICC = -4.2; +4.3). Low income (extreme poverty) in the children's families and absence of maternal schooling were the variables most closely correlated with under-five mortality rate (r = 0.649, p < 0.001 and r = 0.640, p < 0.001, respectively). The fact that Brazil met the fourth target in the MDGs reflected the country's progress in reducing the under-five mortality rate, but the data suggest the rate's possible stabilization in recent years. Meanwhile, social and healthcare indicators revealed the importance of this reduction, challenging the country to maintain and further improve its public policies in this area.