Funding for this research was provided by:
Received: 8 May 2018
Accepted: 19 October 2018
First Online: 20 November 2018
Ethics approval and consent to participate
: The study was approved by the Regional Research Ethical Board at Karolinska Institutet, Stockholm (No. 2013/1272–31/4 and No. 2014/1572–32). Informed consent from individual participants was not required due to the register-based nature of the study.
: Not applicable.
: The authors declare that they have no competing interests.
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