Environment and physical activity dynamics: The role of residential self-selection

Objectives: Within the socio-ecologic framework, diet and physical activity are influenced by individual, inter-personal, organizational, community, and public policy factors. A basic principle underlying this framework is that environments can influence an individual's behavior. However, in the vast majority of cross-sectional and even the few longitudinal studies of this relationship, the question of whether individuals select their area of residence based on physical activity-related amenities is ignored. In this paper, we address a critical methodological issue: self-selection of residential location, which is generally not accounted for, and can significantly compromise research on the relationship between environmental factors and physical activity behaviors. Method: We define and discuss the problem of residential self-selection in the study of neighborhood influences on health and health behavior, review methods used to control for residential self-selection in the literature, and present our strategy for addressing this potentially important source of bias. Conclusion: Existing research has built our understanding of residential self-selection bias, but important gaps remain. Our strategy uses data from a longitudinal cohort study linked to contemporaneous environmental measures to create a multi-equation model system to simultaneously estimate residential choice, environmental influences on physical activity, and downstream health outcomes such as obesity and clinical cardiovascular disease risk factor measures. (C) 2009 Elsevier Ltd. All rights reserved.