Economic, physical, and political characteristics of neighborhood of residence and the risk of low birth weight.

Abstract

Low birth weight remains an important public health problem in the U.S. Most research on low birth weight focuses on individual-level determinants of low birth weight such as health behaviors or use of prenatal care. We sought to determine how characteristics of residential neighborhood influenced low birth weight. We first present a theoretically based framework that describes the mechanisms by which neighborhoods can lead to adverse health outcomes. Our research question centered on whether neighborhood economic, physical and political characteristics directly and indirectly influenced the risk of low birth weight and whether neighborhood factors moderated the relation between individual-level risk factors and low birth weight. We used methods of multi-level statistical modelling to investigate our research question. Direct neighborhood level determinants of low birth weight included high crime (OR=2.49), low wealth (OR=5.50) and low level of political organization (2.54). Interactions and confounding between individual- and neighborhood-level characteristics were observed. When multi-level models accounted for neighborhood levels of wealth, the two-fold gap between African-American and White births was no longer significant. Methods of multi- level modelling facilitated testing of a model emphasizing environmental and social factors in determining poor health outcome. The application of such models also resulted in a better explanatory model for low birth weight. High rates of low birth weight births remain an important public health problem in the U.S., especially among impoverished communities. Most research on low birth weight, however, focuses on individual-level determinants of low birth weight such as maternal education, health behaviors including smoking during pregnancy, and quantity and quality of clinical care (1). Increasingly, public health researchers are recognizing that models of disease etiology that focus exclusively on individual characteristics (e.g., demographic, biologic or personality factors) are insufficient for explaining the complex set of factors that contribute to poor health (2, 3). For example, health behaviors and health outcomes of individuals are influenced by workplace and residential environments (2, 4-14). Studies on the influence of neighborhood residence on health outcomes often analyze individual- and community-level characteristics separately (15, 16). This has, in part, been due to (1) a lack of available data on the contexts of study subjects, (2) lack of easily accessible statistical methods and software for the analyses of complex multi-level data (17- 20), and (3) lack of appropriate theory that explicitly acknowledges the mechanisms by which contexts are related to health outcomes (17, 19, 22-24).

We undertook the current study to contribute to theoretical development of neighborhood effects on health. In particular, we sought to build a conceptual framework describing the mechanisms by which residential characteristics influence health outcomes and low birth weight. We also were interested in answering two research questions concerning the relation between residential neighborhood risk of low birth weight.

(1) Do neighborhood economic, physical and political characteristics directly and indirectly influence the risk of low birth weight? (2) Do neighborhood economic, physical and political characteristics moderate the relation between individual-level risk factors and low birth weight (LBW)?