Received: 22 May 2019
Accepted: 3 October 2019
First Online: 22 October 2019
Compliance with ethical standards
: The authors declare no conflict of interest.
: The study was approved by the Regional Centre for Clinical Quality Development and the National Data Protection Agency approval number 1-16-02-65-17).
: No written consent is necessary in Denmark for studies based on data from national board of health approved national healthcare registries.