PRALIMAP: study protocol for a high school-based, factorial cluster randomised interventional trial of three overweight and obesity prevention strategies

<p>Abstract</p> <p>Background</p> <p>Given the increase in overweight and obesity prevalence in adolescents in the last decade, effective prevention strategies for these conditions in adolescents are urgently needed. The PRALIMAP (Promotion de l'ALImentation et de l'Activité Physique) trial aims to evaluate the effectiveness for these conditions of 3 health promotion strategies -- educational, screening and environmental -- applied singly or in combination in high schools over a 2-year intervention period.</p> <p>Methods</p> <p>PRALIMAP is a stratified 2 × 2 × 2 factorial cluster randomised controlled trial including 24 state high schools in Lorraine, northeastern France, in 2 waves: 8 schools in 2006 (wave 1) and 16 in 2007 (wave 2). Students entering the selected high schools in the 4 academic years from 2006 to 2009 are eligible for data collection. Interventional strategies are organized over 2 academic years. The follow-up consists of 3 visits: at the entry of grade 10 (T0), grade 11 (T1) and grade 12 (T2). At T0, 5,458 (85.7%) adolescents participated. The educational strategy consists of nutritional lessons, working groups and a final party. The screening strategy consists in detecting overweight/obesity and eating disorders in adolescents and proposing, if necessary, an adapted care management program of 7 group educational sessions. The environmental strategy consists in improving dietary and physical activity offerings in high schools and facilities, especially catering. The main outcomes are body size evolution over time, nutritional behaviour and knowledge, health and quality of life. An evaluation process documents how each intervention strategy is implemented in the schools and estimates the dose of the intervention, allowing for a per protocol analysis after the main intention-to-treat analysis.</p> <p>Discussion</p> <p>PRALIMAP aims at improving the prevention and management of overweight and obesity in adolescents by translating current evidence into public health practice. Particular attention is paid to clustering, multiple factorials and long-term duration to address common pitfalls in health promotion trials. The results should inform how best to implement, in a school environment, effective nutrition prevention programs targeting adolescents who are at a point their lives when they develop responsibilities and empowerment for health attitude behaviours.</p> <p>Trial registration</p> <p>This trial is registered at ClinicalTrials.gov under <a href="http://clinicaltrials.gov/ct2/show/NCT00814554">NCT00814554</a>.</p

US pediatric population-level associations of DXA-measured percentage of body fat with four BMI metrics with cutoffs

Four body mass index (BMI) metrics--BMI, BMI z-score, BMI percentile and BMI%--are commonly used as proxy measures for children's adiposity. We sought to determine a BMI metric that is most strongly associated with measured percentage of body fat (%BF) in the US pediatric population stratified by sex, age and race/ethnicity, and to determine cutoffs that maximize the association for each BMI metric. SUBJECTS, DESIGN AND METHODS: %BF was measured by dual-energy X-ray absorptiometry among N=6120 US boys and girls aged 8.0-17.9 years old from the National Health and Nutrition Examination Survey 1999-2004. We fit piecewise linear regression models with cutoffs to %BF data using each BMI metric as the predictor stratified by sex, race/ethnicity and age. The slopes were modeled differently before and after the cutoffs which were determined on the basis of grid searches

Finding Targets for Obesity Intervention in Urban Communities: School-Based Health Centers and the Interface with Affected Youth

Urban schools and school-based health centers (SBHCs) in low-income minority communities may be important points of intervention for overweight and obese youth. To date, little is known about the interface of overweight youth and the public health system through SBHCs. The objective of this study is to determine the prevalence, geographic distribution, sociodemographic, and comorbidity factors associated with obese status as a part of a public health system needs assessment. We conducted a cross-sectional clustered sampling utilizing prospective anthropometric measurement and chart review. Demographic, anthropometric, and medical comorbidity data were collected from 2,630 students in SBHCs in Baltimore, MD, USA. Students were geocoded to their primary residential address and assigned to a census block group using MapInfo v6.5. Demographic and comorbidity associations were analyzed using multivariable logistic regression analysis. Overall, the mean body mass index (BMI) was 25.5 (SD 6.6), and prevalence of obesity (BMI > 95th percentile) and overweight (BMI 85th–95th percentile) was 26.5% and 15.7%, respectively. Obesity was distributed among all the schools without one school being significantly more affected than others. Obese status was associated with gender, poverty, and several medical comorbidities such as asthma, high blood pressure, and disordered eating. Public health practitioners in this SBHC system appear to be faced with a greater burden of obesity than predicted by Centers for Disease Control and Prevention estimates. Given the ongoing interface with affected youth, these schools and health centers may be well situated to deliver public health obesity interventions