Rationale, design and methods of the HEALTHY study physical education intervention component.

The HEALTHY primary prevention trial was designed to reduce risk factors for type 2 diabetes in middle school students. Middle schools at seven centers across the United States participated in the 3-year study. Half of them were randomized to receive a multi-component intervention. The intervention integrated nutrition, physical education (PE) and behavior changes with a communications strategy of promotional and educational materials and activities. The PE intervention component was developed over a series of pilot studies to maximize student participation and the time (in minutes) spent in moderate-to-vigorous physical activity (MVPA), while meeting state-mandated PE guidelines. The goal of the PE intervention component was to achieve > or =150 min of MVPA in PE classes every 10 school days with the expectation that it would provide a direct effect on adiposity and insulin resistance, subsequently reducing the risk of type 2 diabetes in youth. The PE intervention component curriculum used standard lesson plans to provide a comprehensive approach to middle school PE. Equipment and PE teacher assistants were provided for each school. An expert in PE at each center trained the PE teachers and assistants, monitored delivery of the intervention and provided ongoing feedback and guidance.

Recruitment and retention strategies and methods in the HEALTHY study.

HEALTHY was a 3-year middle school-based primary prevention trial to reduce modifiable risk factors for type 2 diabetes in youth. The study was conducted at seven centers across the country. This paper describes the recruitment and retention activities employed in the study. Schools and students were the focus of recruitment and retention. Each center was responsible for the recruitment of six schools; eligibility was based on ability to enroll a sufficient number of predominately minority and lower socioeconomic status students. Study staff met with district superintendents and school principals to verify the eligibility of schools, and to ascertain how appropriate the school would be for conducting the trial. Sixth grade students were recruited employing a variety of techniques; students and their parents did not know whether their school was randomized to the intervention or control arm. This cohort was followed through sixth, seventh and eighth grades. In the eighth grade, an additional sample of students who were not originally enrolled in the study was recruited in a similar manner to participate in data collection to allow for cross-sectional and dose-response secondary analyses. Parents signed informed consent forms and children signed informed assent forms, as per the needs of the local Institutional Review Board. Parents received a letter describing the results of the health screening for their children after data collection in sixth and eighth grades. Retention of schools and students was critical for the success of the study and was encouraged through the use of financial incentives and other strategies. To a large extent, student withdrawal due to out-migration (transfer and geographical relocation) was beyond the ability of the study to control. A multi-level approach that proactively addressed school and parent concerns was crucial for the success of recruitment and retention in the HEALTHY study.