FACTORS ASSOCIATED WITH INFANT MORTALITY IN A BRAZILIAN CITY WITH HIGH HUMAN DEVELOPMENT INDEX

To identify factors associated with infant mortality in a city with good socioeconomic development.

A retrospective cohort study with 7,887 live births in the year of 2012 recorded in the Live Births Information System (SINASC) and associated by linkage with the Mortality Information System (SIM) to identify the deaths in the first year of life. The risk factors were ranked in three levels of determination: distal, intermediate and proximal. The logistic binomial regression models and the multivariate model quantified the impact of the individual variables tested and adjusted the effect of confounding variables. The magnitude of the effect of the explanatory variables was estimated by calculating the crude and adjusted Odds Ratio (OR) and their respective 95% confidence intervals (95%CI), being significant p<0.05.

There were 61 deaths in the cohort and the infant mortality rate was 7.7 per thousand live births. Teenage mother (adjOR 3.75; 95%CI 1.40-10.02), gestational age <32 weeks (adjOR 12.08; 95%CI 2.30-63.38), weight at birth <1500g (adjOR 8.20; 95%CI 1.52-44.23), Apgar score at 1 and 5 minutes of life <7 (adjOR 4.82; 95%CI 2.01-11.55 and adjOR 6.26; 95%CI 1,93-20,30, respectively) and the presence of congenital malformation (adjOR 21.49; 95%CI 7.72-59.82) were risk factors for infant mortality.

The lower relevance of socioeconomic and health care variables and the greater importance of biological factors in determining infant mortality may reflect the protective effect of high economic and social development of the locality.