Funding for this research was provided by:
Received: 24 April 2017
Accepted: 5 February 2018
First Online: 14 February 2018
Ethics approval and consent to participate
: The study was approved by the Ethical Committee of the Karolinska Institutet (registration number 00–012) and by the complementing ethical permission approved by the Ethical Committee of the Karolinska Institutet (registration number 2010/1516–32). Participants were informed about the content and purpose of the study and a written informed consent was obtained from all respondents.
: Not applicable.
: The authors declare that they have no competing interests.
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