Development and usability testing of an internet intervention to increase physical activity in overweight adolescents

Background: internet interventions may provide opportunities for low threshold counseling using feedback to guide and support health behavior,including increased physical activity. research shows that overweight and obese adolescents are less physically active than their peers of normal weight. there are good reasons to believe that internet-based interventions may be particularly suitable for motivating adolescents to increase physical activity,but we need to gain further knowledge of what features are effective and how to design such interventions. objective: to describe the process of development and evaluation of usability of a web-based program for increasing physical activity in overweight adolescents. methods: informed by the self-determination theory,motivational interviewing,and perspectives on self-regulation,this intervention was developed in a stepwise process by an interdisciplinary team of researchers,designers,developers,and representatives from the target group. an iterative qualitative usability testing approach (observation,survey,and interview) was applied in 2 sequences,first in the lab and second in the field,to assess how adolescents (aged 12-16 years) used and experienced the program and to make adjustments to the program based on evaluation of their response. results: the following components were included in the program: self-monitoring through planning and registration of physical activity and graphical response on progress,autonomy supportive individual web-based counseling,forum for social support,and relevant age-adjusted information about physical activity. the first usability test resulted in adjustments related mainly to making the content and aim of the different features more visible and explicit. the second test evaluated the program with adjustments from the first test,revealing that the program was well accepted by the participants and only small aesthetic adjustments had to be made to complete the final version of the internet program,young and active. conclusions: thorough preparation,with clear theory foundation and close monitoring in the developmental phase,as well as contribution and iterative evaluation from the target group,is essential to create a user-friendly and engaging program. the efficacy of the program will be evaluated in a controlled trial. © filippo castiglione.