title: Neighborhood Context and Youth Physical Activity: Differential Associations by Gender and Age.
abstract: OBJECTIVE
  The goal of this research is to examine the extent to which facets of neighborhood sociodemographic contexts influence individual-level physical activity (PA) among youth.
  
  
  METHODS
  Using National Health and Nutrition Examination Survey (NHANES), geographic information systems (GIS), and census data sources, we explicitly test whether built environment factors have differential associations depending on the age and gender of the youth living in urban census tracts.
  
  
  METHODS
  Participants are from the NHANES 2003 to 2006 waves.
  
  
  METHODS
  The study sample for this article was 2706 youth aged 6 to 17 years with valid PA accelerometer measures.
  
  
  METHODS
  A measure of park accessibility was constructed from the 2006 park GIS layer in Environmental System Research Institute ArcGIS 9.3 data. Average daily minutes of moderate to vigorous PA in bouts equal to or longer than 1 minute were recorded using accelerometers over 4 to 7 days.
  
  
  METHODS
  Analysis was conducted with SAS 9.2, including descriptive analyses and linear regression for PA.
  
  
  RESULTS
  Findings suggest that built environment features are especially salient for adolescents and youth living in urban areas. Vigorous activity varied by the age and gender of the youth. For example, greater distance to parks is associated with a decrease in PA among girls and boys aged 6 to 11 years. Among teens, distance to parks is significantly associated with decreases in PA among the total sample and among male teens. However, an increase in population density is associated with less time spent in PA among youth aged 6 to 11 years but more PA among teens.
  
  
  CONCLUSIONS
  These analyses represent an important step to considering the implications of modifiable environmental features for youth and contrast with existing literature for adults. Results speak to the efficacy of built environment measures in urban communities and the importance of considering the possibility of differing patterns of associations in childhood and adolescence and by gender. Results from this research inform policy efforts to interdict in the growing trend of youth inactivity in the United States.
authors.affiliation: 1 Department of Family and Consumer Studies, University of Utah, Salt Lake City, UT, USA.
authors.forename: Lori
authors.initials: L
authors.lastname: Kowaleski-Jones
authors.affiliation: 1 Department of Family and Consumer Studies, University of Utah, Salt Lake City, UT, USA.
authors.forename: Jessie X
authors.initials: JX
authors.lastname: Fan
authors.affiliation: 2 Department of Sociology, University of Utah, Salt Lake City, UT, USA.
authors.forename: Ming
authors.initials: M
authors.lastname: Wen
authors.affiliation: 3 Department of Family and Preventive Medicine, University of Utah, Salt Lake City, UT, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Hanson
mesh_terms: D061725:Accelerometry; D000293:Adolescent; D000367:Age Factors; D019352:Censuses; D002648:Child; D004779:Environment Design / Q000706:statistics & numerical data*; D015444:Exercise; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D009749:Nutrition Surveys; D000068316:Parks, Recreational / Q000706:statistics & numerical data*; D012111:Residence Characteristics / Q000706:statistics & numerical data*; D012737:Sex Factors; D012959:Socioeconomic Factors; D013997:Time Factors
keywords: built environment; children and adolescents; energy balance; neighborhood effects; physical activity