Process evaluation of a school-based overweight and obesity screening strategy in adolescents.

The PRALIMAP (PRomotion de l'ALIMentation et de l'Activité Physique) trial highlights the effectiveness of implementing a screening strategy in high schools to prevent overweight/obesity among adolescents. The strategy comprises three steps: i) body measurements to detect overweight/obese adolescents, ii) a medical interview with each adolescent identified to discuss the findings, and iii) an adapted care management consisting of seven group educational sessions. A process evaluation was conducted in the PRALIMAP trial to assess the effective implementation of the screening strategy activities, and the participation of adolescents and school professionals in them, from a qualitative and a quantitative point of view. The present paper describes the process and the implementation of the screening strategy as performed in the PRALIMAP trial, and discusses the feasibility of such an intervention in high school settings. The ability of nurses to explain the screening results improved with the addition of specialist support. The ability of adolescents to take part in the screening strategy improved when the adapted care management was conducted inside schools and could be increased even further if the waiting time between the three steps could be minimised.

Overweight and obesity prevention for adolescents: a cluster randomized controlled trial in a school setting.

BACKGROUND: Given the increasing prevalence of obesity among youth over the past decade, prevention has become an international public health priority. PURPOSE: To evaluate the 2-year effectiveness of three strategies aimed at preventing overweight and obesity among adolescents in a high school setting. DESIGN: PRomotion de l'ALIMentation et de l'Activité Physique (PRALIMAP) is a school-based RCT. Each study high school was assigned to receive or not, over a 2-year period (Grades 10 and 11), each of three prevention strategies according to a 2 × 2 × 2 factorial school randomization. Data were collected in 2006-2009 and analyzed in 2009-2011. SETTING/PARTICIPANTS: A total of 3538 adolescents (aged 15.6±0.7 years at baseline) in 24 public high schools in Lorraine (northeastern France) completed the PRALIMAP trial. INTERVENTIONS: The prevention strategies were education (development of nutritional knowledge and skills); environment (creation of a favorable environment by improving availability of "healthy" dietary items and physical activity); and screening and care (detection of overweight/obesity and, if necessary, adapted care management). MAIN OUTCOMES MEASURES: The main outcome of interest was BMI; BMI z-score and prevalence of overweight/obesity were considered as secondary outcomes. RESULTS: Adolescents who completed the PRALIMAP trial were younger, less often suspected of having eating disorders and depression, and came from a higher socioeconomic class than those who did not. The 2-year change of outcomes was more favorable in the 12 screening and care high schools compared to the no-screening ones: a 0.11 lower increase in BMI (p=0.0303); a 0.04 greater decrease in BMI z-score (p=0.0173); and a 1.71% greater decrease in overweight/obesity prevalence (p=0.0386). Education and environment strategies were not more effective than no strategy intervention. CONCLUSIONS: Although the screening and care strategy is an effective way to prevent, at 2 years, overweight and obesity among adolescents in a high school setting, its effects over and above no strategy intervention were small. TRIAL REGISTRATION: This study is registered at www.clinicaltrials.govNCT00814554.

Effect of gender on the association between weight status and health-related quality of life in adolescents.

BACKGROUND: Some studies have investigated the association between body mass index (BMI) and health-related quality of life (HRQoL) among adolescents, but their results have been discrepant and few paid attention to the role of gender. The present investigation aimed to assess the relationship between weight status and HRQoL in adolescents and to verify whether it was similar in boys and girls. METHODS: Five thousand two hundred and twenty six adolescents aged 14 to 18 years were included in the PRomotion de l'ALIMentation et de l'Activité Physique (PRALIMAP) trial, a 2x2x2 factorial cluster randomized trial performed in 24 high schools in France. Sociodemographic, anthropometric and HRQoL data were collected. BMI was categorized in four classes (thin, normal-weight, overweight, obese). Linear regression models were used to estimate the association between weight status and HRQoL, adjusting for confounders. RESULTS: The mean age of adolescents was 15.7±0.6 years and their mean BMI was 21.6 ±3.5 kg/m2; 55% were girls. Boys were more often overweight and obese than were girls (overweight: 15.6% vs 14.2%, obese: 4.8% vs 3.3%), and girls were more likely to be thin (5.5% vs 4.5%, p=0.0042). All HRQoL scores were higher for boys (p=<0.0001). Weight status was not associated with physical and social scores neither in boys nor in girls. Conversely, it was associated with mental score, but differently in girls than boys. As compared with normal-weight girls, thin girls had better mental HRQoL (ß=+6.17, p=0.0010), and overweight and obese girls had lower mental HRQoL (ß=-3.89 and ß=-5.90, respectively, p<0.001). Mental HRQoL was lower for thin, overweight and obese boys than for normal-weight boys (ß= -4.97, ß= -1.68 and ß= -3.17, respectively, p<0.0001). CONCLUSIONS: Gender can modify the association between weight status and HRQoL in adolescents. Body image could be an important target of public health programs to improve subjective health during adolescence.

Intervention dose estimation in health promotion programmes: a framework and a tool. Application to the diet and physical activity promotion PRALIMAP trial.

BACKGROUND: Although the outcomes of health promotion and prevention programmes may depend on the level of intervention, studies and trials often fail to take it into account. The objective of this work was to develop a framework within which to consider the implementation of interventions, and to propose a tool with which to measure the quantity and the quality of activities, whether planned or not, relevant to the intervention under investigation. The framework and the tool were applied to data from the diet and physical activity promotion PRALIMAP trial. METHODS: A framework allowing for calculation of an intervention dose in any health promotion programme was developed. A literature reviews revealed several relevant concepts that were considered in greater detail by a multidisciplinary working group. A method was devised with which to calculate the dose of intervention planned and that is actually received (programme-driven activities dose), as well as the amount of non-planned intervention (non-programme-driven activities dose). RESULTS: Indicators cover the roles of all those involved (supervisors, anchor personnel as receivers and providers, targets), in each intervention-related groups (IRG: basic setting in which a given intervention is planned by the programme and may differ in implementation level) and for every intervention period. All indicators are described according to two domains (delivery, participation) in two declensions (quantity and quality). Application to PRALIMAP data revealed important inter- and intra-IRG variability in intervention dose. CONCLUSIONS: A literature analysis shows that the terminology in this area is not yet consolidated and that research is ongoing. The present work provides a methodological framework by specifying concepts, by defining new constructs and by developing multiple information synthesis methods which must be introduced from the programme's conception. Application to PRALIMAP underlined the feasibility of measuring the implementation level. The framework and the tool can be used in any complex programme evaluation. The intervention doses obtained could be particularly useful in comparative trials. TRIAL REGISTRATION: PRALIMAP is registered at ClinicalTrials.gov under NCT00814554.

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

BACKGROUND: 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. METHODS: 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. DISCUSSION: 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. TRIAL REGISTRATION: This trial is registered at ClinicalTrials.gov under NCT00814554.