Infant mortality: analysis of associated factors in a capital of Northeast Brazil

Abstract Objective To analyze the factors associated with infant mortality in Fortaleza, Ceará. Methods A case-control study with a sample of 147 cases and 441 controls. The outcome studied was the occurrence of death among children under one year of age and the explanatory variables were arranged in hierarchical blocks. The value of p <0.20 was adopted as criteria for including variables in the model and p <0.05 for keeping them. Association tests were carried out with chi-square and Maximum Likelihood ratio and the level of significance adopted was 5%. Gross and adjusted Odds Ratios (ORs) were used to measure the strength of association between variables in the non-conditional logistic regression.. confounding factors in the associations of the univariate analysis were controlled through adjusted OR. Finally, a multiple logistic regression was carried out including only the significant variables of each hierarchical level. Results The factors associated with infant mortality were: twin pregnancy (OR: 78.1; 95% CI: 22.1, 275.6) and ≤36 weeks gestational age (OR: 18.8; 95% CI: 6.2; 57.0). Cesarean section is presented as a factor associated with protection. Conclusion The prevention of associated factors identified in this study, such as twin pregnancy and gestational age ≤ 36 weeks, may result in greater reduction in infant mortality rate.