Funding for this research was provided by:
Helse Nord RHF
Text and Data Mining valid from 2019-10-03
Received: 27 March 2019
Accepted: 24 September 2019
First Online: 3 October 2019
Ethics approval and consent to participate
: The study has been approved by the regional ethical committee of North Norway (Reference Number REK Nord 2010/1931, 2013/2271). The Data Inspectorate has also approved the storing of relevant, not identifiable data and the linkage to national registries in the NOWAC study.
: Not applicable.
: The authors declare that they have no competing interests.