Text and Data Mining valid from 2019-12-01
Received: 29 May 2019
Accepted: 5 November 2019
First Online: 5 December 2019
Ethics approval and consent to participate
: This study was approved by the Danish Data Protection Agency. Ethical approval and informed consent is not required for registry-based studies in Denmark.
: Not applicable.
: The authors declare that they have no competing interests.