Background. In the past decade the Internet has become a widely used communication medium that is extensively used by adolescents. Swiss data indicate that the percentage of 14-19 year-olds using the Internet regularly has increased dramatically between 1997 (4%) and 2009 (91%). It is likely that part of this increase is due to an increase in the academic demands. However, research on the impact of Internet use on health is scarce and longitudinal studies following youths over time are lacking. Moreover, studies on Internet use among adolescents do not differentiate between leisure and education/professional use.
Objectives. The main aims of this study are:
(1) To assess the amount of Internet use among adolescents in Vaud differentiating between the time devoted to educational/professional tasks and the time devoted leisure use. We hypothesize that the more demanding the educational pathway, the more likely to use the Internet more often for education/professional purposes.
(2) To assess whether the ratio between educational and leisure use modulates the relationship between Internet use and associated health-related outcomes, namely: psychiatric symptoms, overweight/obesity, and somatic complaints. We hypothesize that when the ratio educational/leisure Internet time is >1 (when the amount of educational time overcomes the amount of leisure time), the association with health-related negative outcomes is minimal or nonexistent.
(3) To assess whether the level and the education/leisure ratio of Internet use vary over time and whether different Internet use trajectories have different effects on health-related outcomes. We hypothesize that the Internet use trajectories will be different depending on the academic pathways and demands.
Secondary aims of this study are:
(1) To define the characteristics of Internet users according to their level of use and to the ratio educational/leisure use.
(2) To describe in what specific applications do adolescents spend their leisure Internet time on and whether these applications change over time.
(3) To establish to what degree the parents’ monitoring attitude towards the Internet has an effect on the adolescents’ use and whether this effect remains over time.
Methods. To reach our objectives we will use a longitudinal design. We will do the baseline collection of data in the schools using a representative sample of 8th graders (N~3000; age 14-15 years) from the canton of Vaud. Afterwards, four follow-up web-based waves at 6, 12, 18 and 24 months will be carried out. Overall, these students will be followed for 2 years which, for most of them, will represent that their final surveys will correspond to their first year of apprenticeship or gymnasium.
Importance and impact. The results of this research will set a framework on the amount and the type of Internet use among adolescents. Such data are necessary for prevention programs to be created and implemented. Moreover, such baseline data will be essential to assess the efficacy of prevention programs. The findings of this study will also allow defining the limits of reasonable Internet use among adolescents together with the best possible education/leisure ratio. Additionally, the results of this research will provide data on the variability of Internet use among adolescents over time, and such longitudinal data will help identify windows of opportunity for prevention. Furthermore, due to its longitudinal design, the results of this research will allow assessing the causality between the amount of Internet use and health-related outcomes.
Finally, we believe that the results of our research will be helpful for public health professionals, clinicians, educators and parents.