RESUMO
AIM: Prevention research has to elucidate how families with overweight children can be convinced to participate in obesity intervention trials. Here we describe the detailed recruitment process for a telephone-based obesity prevention programme for families with overweight children and present participation rates, the study design and a socio-demographic description of participating families. METHODS: Overweight (BMI > 90th percentile) children and adolescents 4-17 years of age were screened via the German paediatrician network CrescNet. The prevention programme (multiple computer aided telephone counselling interviews) was suggested to eligible families via local paediatricians. Participating families were compared anthropometrically and socio-demographically to the entire screening population and to micro-census data, a representative national survey. RESULTS: The screening process assessed 4005 candidates for eligibility. Paediatricians reported having suggested programme participation to 3387 candidates (referred to as 100%). 427 candidates (12.6%) returned a written consent for programme participation. 303 candidates (9.0%) started the intervention. The study population (n = 303) included more obese (45.6% vs. 33.2%; p < 0.001) and fewer overweight participants (40.4% vs. 55.2%; p < 0.001) than the entire screening population. Compared to the micro-census, families with adolescents (8.2% vs. 16.9%; p < 0.001) and single parents (16.0% vs. 23.3%; p < 0.005) were underrepresented in the study population, whereas families living in rural areas were overrepresented (58.7% vs. 50.2%; p < 0.005). CONCLUSIONS: Although 84.6% of the paediatricians forwarded the suggestion for programme participation to eligible families, participation rates for this low-threshold; telephone-based obesity intervention remained very low. "Hard-to-engage groups" for effective obesity prevention seem to include single parents, as well as parents of adolescents.
