Funding for this research was provided by:
Academy of Finland (Skidi‐Kids Research Programme, the project 264276/2012, and the project 288774/2015)
Tays (Expert Responsibility Area of Tampere University Hospital)
Text and Data Mining valid from 2019-11-04
Received: 21 January 2019
Accepted: 21 October 2019
First Online: 4 November 2019
Ethics approval and consent to participate
: The study protocol was approved by the Ethical Committee of the Finnish Institute for Health and Welfare. The educational authorities of all 14 municipalities of the Helsinki Metropolitan Region gave a permission for the study. In line with the instructions of the Finnish National Board on Research Integrity (TENK) in 2009, no parental consent was required when the study was conducted as part of the students’ normal schoolwork. Two of the 14 municipalities had adopted a policy that a written parental consent is always required. These were collected. In the other municipalities, information letters were sent to the parents who had the possibility to withdraw their child from the study. The students were instructed about the purpose of the study and that participation was voluntary and that they can decline to answer any question or withdraw from the survey at any time.
: Not applicable.
: The authors declare that they have no competing interests.