Funding for this research was provided by:
Fundação Calouste Gulbenkian (231980 Academias Gulbenkian do Conhecimento)
Câmara Municipal de Sintra (7819008155)
Received: 26 August 2020
Accepted: 15 October 2020
First Online: 27 October 2020
Ethics approval and consent to participate
: This study is conducted according to the guidelines laid down in the Declaration of Helsinki and it is obtained written informed consent from the children’s legal guardian. Lisbon Academic Medical Centre ethics committee (401/17), the National Data Protection Commission (11468/2017) and the Ethics Boards of each participating school approved the study. Permission from the relevant rights holders of each questionnaire applied was obtained.
: Not applicable.
: The authors declare that they have no competing interests.