title: Measuring psychological, social, and environmental influences on leisure-time physical activity among adults.
abstract: Many of the self-administered scales for measuring physical activity (PA) influences were originally developed for vigorous-intensity exercise, focus on only one domain of influence, and have not been evaluated for both reliability and validity using population-based samples.
  
  
  OBJECTIVE
  This study describes the factorial validity and internal reliability of scales for measuring individual-level psychological, social, and environmental influences on leisure-time PA among adults in the general population.
  
  
  METHODS
  Constructs were identified from a literature review and formative research with a socio-economically diverse sample. Items were generated using previously developed scales and interview data. New items were pre-tested using reliability and principal components analyses, with data collected from a mail survey sent to a randomly selected population-based sample. Qualitative feedback was obtained from a convenience sample and expert panel. A second mail survey provided data for principal components and reliability analyses.
  
  
  RESULTS
  Twenty-eight scales were factorially derived and 24 had acceptable or marginally acceptable levels of internal consistency with Cronbach's alpha values ranging from 0.65 to 0.91.
  
  
  CONCLUSIONS
  The 24 scales are suitable for researchers and practitioners interested in measuring individual-level influences on PA that are consistent with Social Cognitive Theory. More research is required to assess predictive validity, sensitivity to change and test/re-test reliability.
authors.affiliation: School of Human Movement Studies, University of Queensland, St Lucia, Queensland. nburton@hms.uq.edu.au
authors.forename: Nicola W
authors.initials: NW
authors.lastname: Burton
authors.forename: Brian
authors.initials: B
authors.lastname: Oldenburg
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
authors.forename: Gavin
authors.initials: G
authors.lastname: Turrell
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001315:Australia; D003625:Data Collection / Q000379:methods; D004522:Educational Status; D004777:Environment; D015444:Exercise / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D007899:Leisure Activities / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012919:Social Behavior; D012931:Social Environment; D012959:Socioeconomic Factors