Background: In fall 2014, the Danish government implemented a new reform in the Danish public schools in primary and lower secondary education. The reform entailed a longer and more varied school day intended to alternate between regular classes and activities such as play, movement, projects, and workshops. One of the aims in the reform is that physical activity to a greater extent shall be a mandatory part of the syllabus corresponding an average of 45 minutes per day. Thus, the Danish school reform provides a unique opportunity for evaluating the effectiveness of an ambitious nation-wide policy-driven school-based physical activity promotion initiative.
Objective: The overall objective is to examine the effectiveness of the school reform in promoting physical activity and preventing obesity. The study will be conducted as a quasi-experimental design examining a natural experiment.
Methods: Different research projects at SDU have previously (from 1998 to 2012) collected data on objectively measured physical activity using accelerometers, which makes it possible to estimate habitual physical activity before the reform. Moreover, two upcoming data collections will be conducted from 2017-2019 on the same schools as used in the previous research projects. Interrupted time-series analysis will be applied to evaluate the development of habitual physical activity and body mass index (BMI) before and after the implementation of the school reform. To avoid that the analysis of physical activity before and after the reform merely express trends in society, several data points before and after the introduction of the reform are required. New accelerometer technology will be used in the upcoming data collections in 2017-2019, which makes it possible to describe highly accurate estimates of young people's physical activity patterns in various contexts during school-time and transport to school after the introduction of the school reform.
Data on BMI will be collected from the Child Database (Børnedatabasen (BDB)), which is a nation-wide surveillance mandatorily obtained annually by school nurses or pediatricians among 6-7-year old children and 14-15-year old adolescents.
Anders Grøntved (EXE and RICH), Jens Troelsen (AL), Thomas Skovgaard (FIIBL), Niels Christian Møller (EXE and RICH), Peter Lund Kristensen (EXE and RICH) and Søren Brage (Cambridge) are all in the steering committee of the project. Kristian Traberg Larsen is project leader and Natascha Holbæk Pedersen is one of two PhD students at the project. The second PhD student will be recruited during the spring of 2017.