title: Evaluation of a computer-tailored physical activity intervention in adolescents in six European countries: the Activ-O-Meter in the HELENA intervention study.
abstract: OBJECTIVE
  The present study investigates the effect of the Activ-O-Meter, an internet-based computer-tailored physical activity intervention in adolescents in six European centers involved in the HELENA study.
  
  
  METHODS
  Adolescents (12-17 years old) from Vienna, Ghent, Heraklion, Dortmund, Athens, and Stockholm were randomized into intervention and control schools. Participants in the intervention condition received the computer-tailored advice at baseline and after 1 month. Participants in the control condition received a generic standard advice. Effects were evaluated after 1 (n = 675) and 3 months (n = 494) using multi-level modeling. Physical activity levels were measured using the International Physical Activity Questionnaire for adolescents (IPAQ-A).
  
  
  RESULTS
  After 1 month, the intervention group reported higher levels of moderate (beta = -32.8, 95% CI (confidence interval): -64.2 to -1.4) and vigorous (beta = -28.0, 95% CI: -50.7 to -5.3) physical activity in leisure time, as well as higher levels of cycling for transport (beta = -19.1, 95% CI: -34.4 to -7.6) compared to the control group. After 3 months, when the intervention group had received the tailored feedback twice, intervention effects were even stronger. Favorable changes in physical activity levels of all intensities and in different contexts were found in the tailored group compared to the control group. Among adolescents not reaching the physical activity recommendations at baseline similar effects as in the total sample were found.
  
  
  CONCLUSIONS
  The data indicated that the computer-tailored physical activity intervention had positive effects on physical activity levels among the adolescents. However, the implementation of the computer-tailored intervention in the schools was not feasible in all countries.
authors.affiliation: Department of Movement and Sport Sciences, Ghent University, Ghent, Belgium. Ilse.Debourdeaudhuij@UGent.be
authors.forename: Ilse
authors.initials: I
authors.lastname: De Bourdeaudhuij
authors.forename: Lea
authors.initials: L
authors.lastname: Maes
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
authors.forename: Tineke
authors.initials: T
authors.lastname: De Vriendt
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.forename: Mathilde
authors.initials: M
authors.lastname: Kersting
authors.forename: Katerina
authors.initials: K
authors.lastname: Sarri
authors.forename: Yannis
authors.initials: Y
authors.lastname: Manios
authors.forename: Kurt
authors.initials: K
authors.lastname: Widhalm
authors.forename: Michael
authors.initials: M
authors.lastname: Sjöstrom
authors.forename: Jonatan R
authors.initials: JR
authors.lastname: Ruiz
authors.forename: Leen
authors.initials: L
authors.lastname: Haerens
mesh_terms: D000293:Adolescent; D002648:Child; D005060:Europe; D015444:Exercise; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D020407:Internet; D008297:Male; D015397:Program Evaluation; D011795:Surveys and Questionnaires; D014584:User-Computer Interface