Text and Data Mining valid from 2018-04-05
Received: 4 September 2017
Accepted: 23 March 2018
First Online: 5 April 2018
Ethics approval and consent to participate
: The study was approved by the Regional Ethical Review Board of Lund University, Sweden (301/2007, 406/2008), and an informed written consent was obtained from all the patients participating in the 2009 survey in compliance with the Declaration of Helsinki.
: Not applicable.
: The authors declare that they have no competing interests.
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