Funding for this research was provided by:
Text and Data Mining valid from 2019-05-30
Received: 29 September 2018
Accepted: 20 May 2019
First Online: 30 May 2019
Ethics approval and consent to participate
: The Research Ethics Board at Umeå University approved this study. A written consent to participate in the registration of NPCR as well as other quality registries is not legally mandated, however an opt-out procedure is applied so a person can reject to be registered.
: Not applicable.
: The authors declare that they have no competing interests.