The association of preterm birth with area-level deprivation and individual-level factors in the Vancouver census metropolitan area

Evidence suggests area-level socioeconomic inequalities in adverse birth outcomes including preterm birth (PTB), one of the most important causes of perinatal mortality and morbidity throughout the life-course. This study analyzed inequality in PTB in live, singleton births in the Vancouver Census Metropolitan Area from 2006 to 2009 by area-level deprivation measures, and assessed the degree to which individual-level variables might indicate pathways through which area-level disparities manifest. Area-level material, but not social, deprivation was associated with higher odds of PTB. The relative odds of PTB by area-level material deprivation and known individual-level risk factors were modelled using hierarchical logistic regression. After adjusting for individual-level factors, the inequality in PTB by material deprivation was attenuated but not eliminated. Individual-level risk factors may, in part, be pathways through which this association manifests. However, future research and discussion should consider the potential interactions between individuals, environments and policies, and their possible effects on perinatal health.