Funding for this research was provided by:
Velliv Foreningen (19-0170, 19-0170, 19-0170)
Article History
Received: 5 September 2022
Accepted: 23 January 2023
First Online: 27 January 2023
Declarations
:
: This study was conducted in accordance with the 1975 Declaration of Helsinki (ExternalRef removed). The study was approved by the Danish Data Protection Agency, which is an independent authority that supervises compliance with the rules on protection of personal data. The participants were informed about the purpose of the project, and their returning of the questionnaire was interpreted as informed consent and willingness to participate. This was in accordance with Danish regulations at the time of data collection. According to Danish law, questionnaire and register-based studies require neither approval by ethical or scientific committees nor written informed consent ( ExternalRef removed ). It is not possible to apply for ethical approval of studies unless they involved clinical examinations or biological material. The Danish research ethics committee specifically waived the need for consent before collection of any data with the following statement, translated from Danish:<i>“it can be hereby announced that in connection with a questionnaire survey of 15-year-olds such as the one outlined, there is no requirement for informed consent (either oral or written) from parents/guardians”.</i>
: Not applicable.
: The authors declare that they have no competing interests.