title: International variation in neighborhood walkability, transit, and recreation environments using geographic information systems: the IPEN adult study.
abstract: BACKGROUND
  The World Health Organization recommends strategies to improve urban design, public transportation, and recreation facilities to facilitate physical activity for non-communicable disease prevention for an increasingly urbanized global population. Most evidence supporting environmental associations with physical activity comes from single countries or regions with limited variation in urban form. This paper documents variation in comparable built environment features across countries from diverse regions.
  
  
  METHODS
  The International Physical Activity and the Environment Network (IPEN) study of adults aimed to measure the full range of variation in the built environment using geographic information systems (GIS) across 12 countries on 5 continents. Investigators in Australia, Belgium, Brazil, Colombia, the Czech Republic, Denmark, China, Mexico, New Zealand, Spain, the United Kingdom, and the United States followed a common research protocol to develop internationally comparable measures. Using detailed instructions, GIS-based measures included features such as walkability (i.e., residential density, street connectivity, mix of land uses), and access to public transit, parks, and private recreation facilities around each participant's residential address using 1-km and 500-m street network buffers.
  
  
  RESULTS
  Eleven of 12 countries and 15 cities had objective GIS data on built environment features. We observed a 38-fold difference in median residential densities, a 5-fold difference in median intersection densities and an 18-fold difference in median park densities. Hong Kong had the highest and North Shore, New Zealand had the lowest median walkability index values, representing a difference of 9 standard deviations in GIS-measured walkability.
  
  
  CONCLUSIONS
  Results show that comparable measures can be created across a range of cultural settings revealing profound global differences in urban form relevant to physical activity. These measures allow cities to be ranked more precisely than previously possible. The highly variable measures of urban form will be used to explain individuals' physical activity, sedentary behaviors, body mass index, and other health outcomes on an international basis. Present measures provide the ability to estimate dose-response relationships from projected changes to the built environment that would otherwise be impossible.
authors.affiliation: Exercise and Wellness Program, School of Nutrition and Health Promotion & Global Institute of Sustainability (GIOS), Arizona State University, 425 N, 5th Street (MC3020), Phoenix, Arizona. marc.adams@asu.edu.
authors.forename: Marc A
authors.initials: MA
authors.lastname: Adams
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: Frank
authors.forename: Jasper
authors.initials: J
authors.lastname: Schipperijn
authors.forename: Graham
authors.initials: G
authors.lastname: Smith
authors.forename: James
authors.initials: J
authors.lastname: Chapman
authors.forename: Lars B
authors.initials: LB
authors.lastname: Christiansen
authors.forename: Neil
authors.initials: N
authors.lastname: Coffee
authors.forename: Deborah
authors.initials: D
authors.lastname: Salvo
authors.forename: Lorinne
authors.initials: L
authors.lastname: du Toit
authors.forename: Jan
authors.initials: J
authors.lastname: Dygrýn
authors.forename: Adriano Akira Ferreira
authors.initials: AA
authors.lastname: Hino
authors.forename: Poh-chin
authors.initials: PC
authors.lastname: Lai
authors.forename: Suzanne
authors.initials: S
authors.lastname: Mavoa
authors.forename: José David
authors.initials: JD
authors.lastname: Pinzón
authors.forename: Nico
authors.initials: N
authors.lastname: Van de Weghe
authors.forename: Ester
authors.initials: E
authors.lastname: Cerin
authors.forename: Rachel
authors.initials: R
authors.lastname: Davey
authors.forename: Duncan
authors.initials: D
authors.lastname: Macfarlane
authors.forename: Neville
authors.initials: N
authors.lastname: Owen
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D004779:Environment Design / Q000706:statistics & numerical data; D040362:Geographic Information Systems / Q000706:statistics & numerical data; D006801:Humans; D038622:Internationality; D009043:Motor Activity; D011998:Recreation / Q000523:psychology*; D012111:Residence Characteristics / Q000706:statistics & numerical data; D014186:Transportation / Q000379:methods* / Q000706:statistics & numerical data; D016138:Walking / Q000523:psychology* / Q000706:statistics & numerical data