Acceptability, feasibility and effectiveness of a computer-tailored physical activity intervention in adolescents Leen Haerens a, * , Benedicte Deforche a , Corneel Vandelanotte b , Lea Maes c , Ilse De Bourdeaudhuij d a Department of Movement and Sports Sciences, Ghent University, Belgium b Cancer Prevention Research Centre, School of Population Health, University of Queensland, Australia c Department of Public Health, Ghent University, Belgium d Department of Movement and Sports Sciences, Ghent University, Belgium Received 17 October 2006; received in revised form 5 January 2007; accepted 7 January 2007 Abstract Objective: To evaluate acceptability, feasibility and effectiveness of computer-tailored physical activity education among adolescents. Methods: Two classes of 7th graders from 10 randomly selected schools were assigned to the intervention (computer-tailored intervention, n = 139) or control (no-intervention, n = 142) condition. Questionnaires were completed 1 week before and 3 months after the intervention. The computer-tailored intervention was completed during classes. Results: Students had few problems with the diagnostic questions and with the use of a computer. About half of the students evaluated the advice as interesting and easy to understand and about 40% as personally relevant, easy to use and credible. Half of students evaluated the advice as too long and only 33% reported to have used the advice. The computer-tailored intervention was effective for increasing school related physical activity levels with on average 25 min per week (F = 3.4, P  .05), but not for increasing total physical activity or leisure time physical activity. Conclusions: A 1-h computer-tailored intervention offered during class-time has the potential to increase school related physical activity. Practice implications: Although favourable effects of large scale implementation may be expected, some adaptations that might increase effectiveness should be investigated in the future. # 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Tailoring; Computer; Physical activity; Intervention; Adolescent 1. Introduction Adolescents should engage in physical activity of moderate to vigorous intensity (MVPA) for at least 60 min and up to several hours daily for enhanced health and weight control [1–3]. During the last 20 years physical activity has declined in all age groups [1,4] and decreased markedly across adolescence [1,5]. Hence, there is a strong need for effective interventions that promote physical activity among adolescents. During the past decade computer-tailored interventions have emerged as a new and cost-effective form of theory- driven health education [6–7]. Computer-tailored interven- tions provide respondents with personally adapted feedback about their present health behavior and with personally adapted suggestions to change behaviors. An automated expert system takes demographic, behavioral and psychoso- cial characteristics into consideration by linking a compu- terised questionnaire to a comprehensive message library [8– 9]. Compared with non-tailored messages, tailored messages are more likely to be read and remembered, saved and discussed with others, perceived as interesting, personally relevant and as though they were written especially for them [10–12]. The behavioral effects of computer-tailored inter- ventions have mainly been investigated in adults [6-7,13–16] and efficacy was demonstrated. The evidence was most www.elsevier.com/locate/pateducou Patient Education and Counseling 66 (2007) 303–310 * Corresponding author at: Ghent University, Department of Movement and Sports Sciences, Watersportlaan 2, 9000 Gent, Belgium. Tel.: +32 9 264 8686; fax: +32 9 264 6484. E-mail address: Leen.Haerens@UGent.be (L. Haerens). 0738-3991/$ – see front matter # 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.pec.2007.01.003