Text and Data Mining valid from 2019-03-28
Received: 17 December 2018
Accepted: 21 March 2019
First Online: 28 March 2019
Ethics approval and consent to participate
: All participants gave informed written consent and the regional ethical board in Gothenburg approved the study.The regional ethical board in Gothenburg located at Sahlgrenska University hospital approved the study.
: Not applicable.
: The authors declare that they have no competing interests.
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