Funding for this research was provided by:
Vetenskapsrådet (2014-2517, 2014-10134 and 2016-01176)
Text and Data Mining valid from 2018-07-03
Received: 5 March 2018
Accepted: 10 June 2018
First Online: 3 July 2018
Ethics approval and consent to participate
: The study was approved by the Regional Ethical Review Board of Lund University (no. 2012/795). No informed consent was required because the study used anonymous data from national health records over several decades.
: Not relevant.
: The authors declare that they have no competing interests.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.