Funding for this research was provided by:
The North Norwegian Health Authorities (ID 5645, ID 9167, ID 9168, ID 10295, ID 12156)
Text and Data Mining valid from 2017-11-14
Received: 12 July 2017
Accepted: 1 November 2017
First Online: 14 November 2017
Compliance with ethical standards
: All participants provided written informed consent; the study was approved by the Regional Committee of Research Ethics and was conducted in accordance with the World Medical Association Declaration of Helsinki.