The IDEFICS intervention trial to prevent childhood obesity: design and study methods.

INTRODUCTION: One of the major research dimensions of the Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS (IDEFICS) study involved the development, implementation and evaluation of a setting-based community-oriented intervention programme for primary prevention of childhood obesity. In this supplement of Obesity Reviews, a compilation of key results of the IDEFICS intervention is packaged in a series of complementary papers. OBJECTIVE: This paper describes the overall design and methods of the IDEFICS intervention in order to facilitate a comprehensive reading of the supplement. In addition, some 'best practice' examples are described. RESULTS: The IDEFICS intervention trial was conducted to assess whether the IDEFICS intervention prevented obesity in young children aged 2 to 9.9 years. The study was a non-randomized, quasi-experimental trial with one intervention matched to one control region in each of eight participating countries. The intervention was designed following the intervention mapping framework, using a socio-ecological theoretical approach. The intervention was designed to address several key obesity-related behaviours in children, parents, schools and community actors; the primary outcome was the prevalence of overweight/obesity according to the IOTF criteria based on body mass index. The aim was to achieve a reduction of overweight/obesity prevalence in the intervention regions. The intervention was delivered in school and community settings over a 2-year period. Data were collected in the intervention and control cohort regions at baseline and 2 years later.