Text and Data Mining valid from 2019-04-26
Received: 29 November 2017
Accepted: 12 April 2019
First Online: 26 April 2019
Ethics approval and consent to participate
: The study was approved by the Regional Ethical Review Board in Stockholm, Sweden (Dnr. 2011/330–31/3), according to which the informed consent of participants was not required.
: Not applicable.
: The authors declare that they have no competing interests.
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