Multivariate analysis of state variation in breastfeeding rates in the United States

Objectives. We sought to determine the impact of sociodemographic and behavioral factors and state legislation on breastfeeding initiation (child ever fed breastmilk) and duration. Methods. We used data from a nationally representative study of children aged 6 to 71 months (N=33121); we calculated unadjusted and adjusted state estimates for breastfeeding initiation and duration. We used logistic regression models to examine factors associated with never breastfeeding or breastfeeding less than 6 months. We conducted a multilevel analysis of state legislation's role. Results. There were wide state variations in breastfeeding initiation and duration. The western and northwestern states had the highest rates. Covariate adjustment accounted for 25% to 30% of the disparity. Multivariate analysis showed that the adjusted odds of not being breastfed were 2.5- to 5.15-times greater in southern states compared with Oregon (reference). Children in states without breastfeeding legislation had higher odds of not being breastfed. Conclusions. Sociodemographic and maternal factors do not account for most breastfeeding rate variation. The association with breastfeeding legislation should be explored and may reflect cultural norms.