Community-based obesity prevention in Australia: Background, methods and recruitment outcomes for the evaluation of the effectiveness of OPAL (Obesity Prevention and Lifestyle)

Background: The Obesity Prevention and Lifestyle (OPAL) intervention program targets families and communities to improve children’s eating and physical activity patterns. We outline the quantitative evaluation design and recruitment results for baseline data collection. Methods: A longitudinal quasi-experimental design, with baseline data collection and five-year follow-up. Participants targeted are children, parents, and school principals/directors from primary, secondary/R-12 schools, pre-schools, childcare and out-of-school-hours-care (OSHC) centers in 20 selected communities across South Australia (SA), and one in the Northern Territory (NT). A total of 277 (262 SA, 15 NT) schools participated; 4860 9-11 year olds and 1164 12-16 year olds completed a questionnaire. Anthropometric measures were taken from 5531 students; 6552 parents, 276 pre/school/childcare directors, 139 OSHC directors and 237 principals completed questionnaires. Data include measurements of child participants’ weight/height/waist circumference; paper-based/online surveys of informants in early childhood, primary/secondary school and community settings; and secondary growth check data for 4-5 year old children. Serial cross-sectional analyses will compare intervention to matched comparison communities. Results: Overall school response rate was 50%. Student response rates were 20-22% and 11-13% (questionnaires and measurements respectively); 14-21% of parents, 49-55% of directors, and 26-44% of principals completed and returned questionnaires. Changes to child weight status; eating practices; sleep, physical activity/sedentary behaviors; physical environments; community capacity; and economic evaluation (Quality Adjusted Life year gain) will examine program effectiveness. Conclusions: As the most significant program of its kind in Australia, OPAL will contribute to obesity prevention efforts on an international scale.