Multilevel Mediation Analysis, with an Application to Explore Racial Disparity in Physical Activity and Obesity

• Activity Number: 452
• Type: Contributed
• Date/Time: Wednesday, August 6, 2014 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Qingzhao Yu*+ and Richard Scribner and Claudia Leonardi and Chi Li and Lu Zhang and Neal Simonsen
• Companies: and LSUHSC and LSUHSC and LSUHSC and LSUHSC and
• Keywords: environmental factors ; mediation analysis ; obesity ; physical activity ; racial disparity

Abstract

Research has shown a consistent racial disparity in obesity between whites and blacks in US adults, and kids. Whites have a lower obesity rate when compared with blacks and Hispanics based on the 2003-2004 NHANES data. A similar racial disparity is seen in physical activities. Research also suggests that several characteristics of the built environment may influence physical activity including street network connectivity, population density, and land-use pattern. However the relationships might be different for inner-city and suburban residents. In this study, we propose general definitions on mediation effects, based on which we propose a Bayesian mediation analysis with multilevel structure to better understand the relationship among race, environmental factors, physical activities, and obesity. We will combine NHANES data with census data and use both individual and tract level variables to explore the racial disparity in physical activity as well as obesity. We will differentiate and report the contribution of each environmental factor to the racial disparities, and we will determine the degree to which mediation effects are different between inner-city and suburban residents.