Impact of a web-based intervention supplemented with text messages to improve cancer prevention behaviors among adolescents: Results from a randomized controlled trial.

OBJECTIVE
To assess the impact of a web-based intervention supplemented with text messages to reduce cancer risk linked with smoking, unhealthy diet, alcohol consumption, obesity, sedentary lifestyle and sun exposure.

METHODS
A total of 2001 voluntary adolescents from Spain and Mexico were recruited between 2009 and 2012 and randomly assigned to: one control group and two experimental groups, which received exclusively the online intervention (experimental group 1) or the intervention supplemented with encouraging text messages (experimental group 2). The educational intervention was based on both: successful psychosocial models (i.e. A.S.E. and Transtheoretical model) and the school curriculum.

RESULTS
After a 9-month follow-up, the prevalence of students who did not eat fruit was reduced significantly in all groups: experimental group 1 (-62.6%), experimental group 2 (-71.5%) and even the control group (-66.8%). Being overweight was only reduced in the experimental group 2 (-19.6%). The total cancer behavioral risk score, which ranged from 0 to 100 points (highest risk), was significantly reduced in the experimental group 1 (-3.5 points) and in the experimental group 2 (-5.3 points). The text-supplemented online intervention increased the probability of improving the post-test total cancer behavioral risk (OR=1.62).

CONCLUSIONS
The web-based intervention supplemented with text messages had a positive global impact, but it lead to only minimal changes in risky behaviors. This intervention appears useful in controlling overweight adolescents.