Main characteristics and participation rate of European adolescents included in the HELENA study
1 Inserm U955, IFR 114/IMPRT, Faculty of Medicine, Université Lille Nord de France, F-59037, Lille, France
2 CIC-PT- 9301-CH&U-Inserm of Lille, CHRU de Lille, F-59037, Lille, France
3 Department of Public Health, Ghent University, B-9000, Ghent, Belgium
4 GENUD (Growth, Exercise, NUtrition and Development) Research Group, Department of Physiotherapy and Nursing, School of Health Sciences, University of Zaragoza, Avd. Domingo Miral s/n, E-50009, Zaragoza, Spain
5 Department of Health and Human Performance, Faculty of Physical Activity and Sport Sciences (INEF), Universidad Politécnica de Madrid, C/Martín Fierro, 7, E-28040, Madrid, Spain
6 Laboratoire d’épidémiologie et de santé publique, Inserm U744, Institut Pasteur de Lille, Université Lille Nord de France, F-59024, Lille, France
7 Department of Biosciences and Nutrition, Unit for Preventive Nutrition, Karolinska Institutet, Karolinska Institutet, S-10044, Huddinge, Sweden
8 Istituto Nazionale di Ricerca per gli Alimenti de la Nutrizione, I-00178, Rome, Italy
9 Medical University of Vienna, A-1040, Vienna, Austria
10 Department of Medical Physiology School of Medicine, University of Granada, E-18071, Granada, Spain
11 Faculty of Medicine, University of Crete, GR-710 03, Heraklion, Greece
12 Department of Paediatrics, University of Pecs, H-7624, Pécs, Hungary
13 Research Institute of Child Nutrition Dortmund, Rheinische Friedrich-Wilhelms-Universität Bonn, G-44225, Dortmund, Germany
14 Department of Consumer & Sensory Sciences, Campden BRI, UK-GL1, Gloucestershire, United Kingdom
Archives of Public Health 2012, 70:14 doi:10.1186/0778-7367-70-14Published: 19 June 2012
Participation rate and response rate are key issues in a cross sectional large-scale epidemiological study. The objective of this paper is to describe the study population and to evaluate participation and response rate as well as the key nutritional status variables in male and female adolescents involved in the HELENA study.
A multi-stage random cluster sampling with a target sample of 3000 adolescents aged [12.5 to 17.5] years, stratified for geographical location and age, was carried out. Information for participants and non-participants (NP) was compared, and participation and response rates to specific questionnaires were discussed.
3,865 adolescents aged [12.5 to 17.5] years (1,845 females) participated in the HELENA study, of whom 1,076 (568 females) participated in the blood sampling. 3,528 (1,845 females) adolescents were finally kept for statistical analysis. Participation rates for the schools and classes differed importantly between countries. The participation rate of pupils within the participating classes also differed importantly between countries. Sex ratio, mean age and BMI were similar between NP and participating adolescents within each centre, and in the overall sample. For all the questionnaires included in the database, the response rate of questionnaires was high (more than 80% of questions were completed).
From this study it could be concluded that participation rate differed importantly between countries, though no bias could be identified when comparing the key study variables between participants and non-participants. Response rate for questionnaires was very high. Future studies investigating lifestyle and health in adolescents can optimize their methods when considering the opportunities and barriers observed in the HELENA study.