title: Utility of computer-assisted approaches for population surveillance of physical activity.
abstract: BACKGROUND
  Computer-assisted techniques may be a useful way to enhance physical activity surveillance and increase accuracy of reported behaviors.
  
  
  OBJECTIVE
  Evaluate the reliability and validity of a physical activity (PA) self-report instrument administered by telephone and internet.
  
  
  METHODS
  The telephone-administered Active Australia Survey was adapted into 2 forms for internet self-administration: survey questions only (internet-text) and with videos demonstrating intensity (internet-video). Data were collected from 158 adults (20-69 years, 61% female) assigned to telephone (telephone-interview) (n = 56), internet-text (n = 51), or internet-video (n = 51). Participants wore an accelerometer and completed a logbook for 7 days. Test-retest reliability was assessed using intraclass correlation coefficients (ICC). Convergent validity was assessed using Spearman correlations.
  
  
  RESULTS
  Strong test-retest reliability was observed for PA variables in the internet-text (ICC = 0.69 to 0.88), internet-video (ICC = 0.66 to 0.79), and telephone-interview (ICC = 0.69 to 0.92) groups (P-values < 0.001). For total PA, correlations (ρ) between the survey and Actigraph+logbook were ρ = 0.47 for the internet-text group, ρ = 0.57 for the internet-video group, and ρ = 0.65 for the telephone-interview group. For vigorous-intensity activity, the correlations between the survey and Actigraph+logbook were 0.52 for internet-text, 0.57 for internet-video, and 0.65 for telephone-interview (P < .05).
  
  
  CONCLUSIONS
  Internet-video of the survey had similar test-retest reliability and convergent validity when compared with the telephone-interview, and should continue to be developed.
authors: Dept of Epidemiology, Human Genetics, and Environmental Sciences, University of Texas School of Public Health, Austin, TX.
authors: MeLisa
authors: M
authors: Creamer
authors: Heather R
authors: HR
authors: Bowles
authors: Belinda
authors: B
authors: von Hofe
authors: Kelley
authors: K
authors: Pettee Gabriel
authors: Harold W
authors: HW
authors: Kohl
authors: Adrian
authors: A
authors: Bauman
mesh_terms: D061725:Accelerometry; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D020407:Internet; D007406:Interview, Psychological; D008297:Male; D008875:Middle Aged; D009043:Motor Activity; D011159:Population Surveillance / Q000379:methods*; D015203:Reproducibility of Results; D057566:Self Report; D011795:Surveys and Questionnaires; D013689:Telephone; D014741:Video Recording; D055815:Young Adult