Received: 28 June 2018
Accepted: 24 September 2018
First Online: 12 October 2018
Ethics approval and consent to participate
: The study was performed according to the Helsinki declaration and approved by the Regional Ethics Committee in Stockholm (ref number 2018/204–31) at 21 February 2018. Informed consent was waived because of the retrospective design of this study that did not involve any additional risk for patients.
: Not applicable.
: The authors declare that they have no competing interests.
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