Funding for this research was provided by:
Text and Data Mining valid from 2020-05-05
Received: 21 January 2019
Accepted: 3 March 2020
First Online: 5 May 2020
Ethics approval and consent to participate
: The study is based upon data which were collected routinely. An application was made to use data from patients without their consent, and this was approved by the Regional Committee for Medical and Health Research Ethics for Western Norway (237.06).
: Not applicable.
: The authors declare that they have no competing interests.