Received: 9 March 2020
Accepted: 17 January 2021
First Online: 26 January 2021
Ethics approval and consent to participate
: Permission for this study was granted by the Danish Data Protection Agency (ID no. 2007-58-0015). No permission from the regional Ethics Committee was needed since the study was purely registry-based.
: Not applicable.
: The authors declare that they have no competing interests.