Who participates in a computer-tailored physical activity program delivered through the Internet? A comparison of participants' and non-participants' characteristics

Data was collected in two ways. First, 5706 brochures with a call to participate in a physical activity program, with as key element a website-delivered tailored physical activity advice, were distributed indirectly (through their ildren) to parents of all pupils in 14 primary and secondary schools in Belgium. Parents were asked to return the reply card mentioning if they wanted to participate or not. Second, characteristics of participating and non-participating parents were collected by distributing 2000 short questionnaires to pupils between 10–18 years of age, in 12 of the 14 schools. Chi-square analysis and binary logistic regressions were used to compare characteristics of those parents who showed interest (i.e. positive response on reply card) or actually participated (completed online assessment) in a website-delivered physical activity intervention with the characteristics of those parents who showed no interest or did not participate.In total 1730 pupils (87% respondents), completed the short questionnaire concerning their parents' age, occupation (to derive the socio-economic status) and physical activity habits. The results of the binary logistic regression showed that mothers were more likely to show interest (Odds Ratio (OR) = 1.68, p < 0.001) and participate (OR = 2.27, p < 0.005) in the program than fathers. High socioeconomic status (OR = 3.42, p < 0.001) and being employed (OR = 3.03, p < 0.001) were also significant predictors for showing interest but not for participation. Age and physical activity level did neither predict interest nor participation.Both younger and older adults as well as physically active and inactive people participated in our online computer-tailored physical activity program when recruitment was done through schools. However, other health-education programs are still needed to reach all segments of the population equally.Epidemiological evidence shows that physical inactivity is an independent risk factor for developing cor