title: Spatially Modelling the Association Between Access to Recreational Facilities and Exercise: The 'Multi-Ethnic Study of Atherosclerosis'.
abstract: Numerous studies have investigated the relationship between the built environment and physical activity. However these studies assume that these relationships are invariant over space. In this study, we introduce a novel method to analyze the association between access to recreational facilities and exercise allowing for spatial heterogeneity. In addition, this association is studied before and after controlling for crime, a variable that could explain spatial heterogeneity of associations. We use data from the Chicago site of the Multi-Ethnic Study of Atherosclerosis of 781 adults aged 46 years and over. A spatially varying coefficient Tobit regression model is implemented in the Bayesian setting to allow for the association of interest to vary over space. The relationship is shown to vary over Chicago, being positive in the south but negative or null in the north. Controlling for crime weakens the association in the south with little change observed in northern Chicago. The results of this study indicate that spatial heterogeneity in associations of environmental factors with health may vary over space and deserve further exploration.
authors.affiliation: University of North Carolina at Chapel Hill, Department of Biostatistics, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Berchuck
authors.affiliation: Yale University, Department of Biostatistics, Yale School of Public Health, New Haven, CT, USA.
authors.forename: Joshua L
authors.initials: JL
authors.lastname: Warren
authors.affiliation: University of North Carolina at Chapel Hill, Department of Biostatistics, Gillings School of Global Public Health, Chapel Hill, NC, USA. University of North Carolina at Chapel Hill, Carolina Population Center, Chapel Hill, NC, USA.
authors.forename: Amy H
authors.initials: AH
authors.lastname: Herring
authors.affiliation: University of North Carolina at Chapel Hill, Department of Epidemiology, Gillings School of Global Public Health, Chapel Hill, NC, USA.
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
authors.affiliation: University of Michigan, Center for Social Epidemiology and Population Health, Ann Arbor, MI, USA.
authors.forename: Kari A B
authors.initials: KA
authors.lastname: Moore
authors.affiliation: Division of Epidemiology, University of California, Berkeley, CA.
authors.forename: Yamini K
authors.initials: YK
authors.lastname: Ranchod
authors.affiliation: Drexel University, School of Public Health, Philadelphia, PA, USA.
authors.forename: Ana V
authors.initials: AV
authors.lastname: Diez-Roux
keywords: Environment; Physical activity; Spatially varying coefficients; Tobit regression