title: Using pedometers to estimate ambulatory physical activity in Vietnam.
abstract: BACKGROUND
  Pedometer measurement of physical activity (PA) has been shown to be reliable and valid in industrialized populations, but its applicability in economically developing Vietnam remains untested. This study assessed the feasibility, stability and validity of pedometer estimates of PA in Vietnam.
  
  
  METHODS
  250 adults from a population-based survey were randomly selected to wear Yamax pedometers and record activities for 7 consecutive days. Stability and concurrent validity were assessed using intraclass correlation coefficients (ICC) and Spearman correlation coefficients.
  
  
  RESULTS
  Overall, 97.6% of participants provided at least 1 day of usable recordings, and 76.2% wore pedometers for all 7 days. Only 5.2% of the sample participants were involved in work activities not measurable by pedometer. The number of steps increased with hours of wear. There was no significant difference between weekday and weekend in number of steps, and at least 3 days of recordings were required (ICC of the 3 days of recordings: men 0.96, women 0.97). Steps per hour were moderately correlated (men r = .42, women r = .26) with record estimates of total PA.
  
  
  CONCLUSIONS
  It is feasible to use pedometers to estimate PA in Vietnam. The measure should involve at least 3 days of recording irrespective of day of the week.
authors.affiliation: Menzies Research Institute, University of Tasmania, Hobart, Australia.
authors.forename: Au Bich
authors.initials: AB
authors.lastname: Thuy
authors.forename: Leigh
authors.initials: L
authors.lastname: Blizzard
authors.forename: Michael
authors.initials: M
authors.lastname: Schmidt
authors.forename: Costan
authors.initials: C
authors.lastname: Magnussen
authors.forename: Emily
authors.initials: E
authors.lastname: Hansen
authors.forename: Terence
authors.initials: T
authors.lastname: Dwyer
mesh_terms: D061725:Accelerometry / Q000592:standards*; D000328:Adult; D002908:Chronic Disease / Q000517:prevention & control; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012424:Rural Population; D014505:Urban Population; D014744:Vietnam; D016138:Walking / Q000706:statistics & numerical data*