Hansen, Claus D.
Kirkeby, Mette J.
Kjelmann, Kristian G.
Andersen, Johan H.
Møberg, Rasmus J.
Article History
Received: 1 February 2021
Accepted: 19 October 2021
First Online: 8 November 2021
Declarations
:
: The study was approved by the Danish Data Protection Agency prior to collecting the data in October 2003. The participants were informed about the purpose of the project and returning a filled in questionnaire was interpreted as informed consent to participate. This was in accordance with the regulation at the time of collecting the data in Denmark. According to Danish law (Act on Research Ethics Review of Health Research Projects), available at: ExternalRef removed, questionnaire and register-based studies require neither approval by ethical or scientific committees nor written informed consent. It was not possible to apply for ethical approval of studies unless they involved clinical examinations or biological material. The linking of information across registers was re-approved by the Danish Data Protection Agency in 2009 (Study No. 2009-41-3761). All procedures were performed in accordance with relevant guidelines including the Declaration of Helsinki (DoH-Oct2000).
: Not applicable.
: No competing interests.