title: Development of a Scottish physical activity questionnaire: a tool for use in physical activity interventions.
abstract: OBJECTIVE
  Three studies were undertaken to establish the reliability and validity of the Scottish physical activity questionnaire (SPAQ), developed to aid seven day recall of leisure and occupational physical activity.
  
  
  METHODS
  To establish reliability, SPAQs (n = 34) were completed on a Monday and the following Wednesday. Thus each questionnaire measured four identical days. To establish concurrent validity, 94 participants completed a SPAQ and an adapted stage of exercise behaviour change questionnaire. Responses to SPAQ were then analysed by stage of exercise behaviour change. In a further study of criterion validity, 30 volunteers wore a Caltrac motion sensor for four consecutive days, after which they completed a SPAQ.
  
  
  RESULTS
  In the first study, total physical activity had a coefficient of repeatability (R) of 53 minutes. Occupational physical activity showed a similar variance (R = 54.6 minutes) but leisure physical activity was more reliable (R = 29.3 minutes). The main variation in occupational physical activity was found to be walking (R = 39.8 minutes). In study 2, a one way analysis of variance showed the expected relation between physical activity and stage of exercise behaviour change, confirming the concurrent validity of SPAQ with the stage of exercise behaviour change model. In study 3, several erroneous recordings affected both SPAQ and the Caltrac results (kcal). After relevant corrections had been made, the correlation between the two measurement devices was 0.52 (p < 0.05).
  
  
  CONCLUSIONS
  SPAQ has been shown to be reliable and to hold strong concurrent validity and limited criterion validity. The main limitation in SPAQ appears to be the measurement of occupational walking. It is therefore recommended that further work be conducted to refine the measurement of this physical activity component. It is evident nonetheless that SPAQ can be used with confidence to measure outcomes in physical activity interventions when account is taken of its limitations.
authors.affiliation: University of Glasgow, Centre of Exercise Science and Medicine, Scotland.
authors.forename: M
authors.initials: M
authors.lastname: Lowther
authors.forename: N
authors.initials: N
authors.lastname: Mutrie
authors.forename: C
authors.initials: C
authors.lastname: Loughlan
authors.forename: C
authors.initials: C
authors.lastname: McFarlane
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001519:Behavior; D016001:Confidence Intervals; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007899:Leisure Activities; D016014:Linear Models; D008297:Male; D011939:Mental Recall; D009043:Motor Activity / Q000502:physiology*; D009790:Occupations / Q000145:classification; D017063:Outcome Assessment, Health Care; D015203:Reproducibility of Results; D012606:Scotland; D011795:Surveys and Questionnaires; D016138:Walking / Q000502:physiology