title: A novel assessment of adolescent mobility: a pilot study.
abstract: BACKGROUND
  The accurate measurement of daily mobility and travel to destinations beyond the residential neighbourhood has been identified as an important but almost systematically overlooked factor when investigating the relationship between exposure to the built environment and physical activity. The recent development of VERITAS - a web-based application nested within a computer-assisted personal interview - allows researchers to assess daily mobility, travel to regular destinations, and perceived neighbourhood boundaries using interactive mapping technology. The aims of this pilot study were to (1) demonstrate the feasibility and functionality of using VERITAS in an adolescent sample, and (2) compare urban form characteristics and geometric features of the perceived neighbourhood with traditional neighbourhood delimitations.
  
  
  METHODS
  Data were collected and analysed for twenty-eight participants (14 male, 15.9 ± 1.48 years) in 2013. Participants underwent anthropometric assessment before completing a custom-designed VERITAS protocol under the supervision of trained interview technicians. Regularly visited destinations, school travel routes, transportation modes, travel companions, and perceived neighbourhood boundaries were assessed. Data were imported into ArcGIS and street network distances between the home and each geolocated destination were generated. Convex hull activity spaces were derived from destinations. Urban form variables and geometric characteristics were compared between the perceived neighbourhood, existing meshblocks, 1 mile Euclidean buffers, and 1 km network buffers.
  
  
  RESULTS
  In total, 529 destinations were geolocated, 58% of which were outside the perceived neighbourhood boundary. Active travel was inversely associated with distance to destinations (r = -.43, p < .05) and traveling with adults (r = -.68, p < .01). Urban form and geometric characteristics of the perceived neighbourhood were different from those in other neighbourhood delimitations.
  
  
  CONCLUSIONS
  This study demonstrates the feasibility of using VERITAS to assess mobility within adolescent populations. Our results also illustrate the potential novelty and use of user-defined spaces, and highlight the limitations of relying on restricted definitions of place (i.e., administrative or residential-focused neighbourhoods) when assessing environmental exposure.
authors.affiliation: Human Potential Centre, Auckland University of Technology, Private Bag 92006, Auckland, 1142, Auckland, New Zealand. tom.stewart@aut.ac.nz.
authors.forename: Tom
authors.initials: T
authors.lastname: Stewart
authors.affiliation: Human Potential Centre, Auckland University of Technology, Private Bag 92006, Auckland, 1142, Auckland, New Zealand. scott.duncan@aut.ac.nz.
authors.forename: Scott
authors.initials: S
authors.lastname: Duncan
authors.affiliation: Inserm, U707, Paris, France. chaix@u707.jussieu.fr.
authors.forename: Basile
authors.initials: B
authors.lastname: Chaix
authors.affiliation: CRCHUM, Department of social and preventive medicine, Université de Montréal, Montreal, Canada. yan.kestens@umontreal.ca.
authors.forename: Yan
authors.initials: Y
authors.lastname: Kestens
authors.affiliation: Research Unit for Active Living, Department of Sport Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark. jschipperijn@health.sdu.dk.
authors.forename: Jasper
authors.initials: J
authors.lastname: Schipperijn
authors.affiliation: Human Potential Centre, Auckland University of Technology, Private Bag 92006, Auckland, 1142, Auckland, New Zealand. grant.schofield@aut.ac.nz.
authors.forename: Grant
authors.initials: G
authors.lastname: Schofield
mesh_terms: D000293:Adolescent; D004779:Environment Design; D015444:Exercise; D005240:Feasibility Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D020407:Internet; D008297:Male; D010465:Perception; D010865:Pilot Projects; D012111:Residence Characteristics; D012574:Schools; D012984:Software; D014186:Transportation; D014195:Travel; D014505:Urban Population