Received: 29 October 2020
Accepted: 20 April 2021
First Online: 3 May 2021
: The current study was approved by The Norwegian Regional Committee for Medical and Health Research Ethics (REC), “Ref 2012/1619/REK Sør-Øst”. REC granted exemption from the requirement of consent from the individuals included in this register-based study.
: Not applicable.
: The authors have no competing interests.