Del Risco Kollerud, Ruby
Ruud, Ellen
Haugnes, Hege S.
Cannon-Albright, Lisa A.
Thoresen, Magne
Nafstad, Per
Vlatkovic, Ljiljana
Blaasaas, Karl Gerhard
Næss, Øyvind
Claussen, Bjørgulf
Funding for this research was provided by:
StraStiftelsen The Norwegian Cancer Society The Research Council of Norway
Article History
Received: 14 December 2018
Revised: 13 March 2019
Accepted: 13 March 2019
First Online: 10 April 2019
Competing interests
: The authors declare no competing interests.
: The study was performed in accordance with the Declaration of Helsinki. The project was approved by the Regional Committees for Medical and Health Research Ethics, (REK Sør-Øst: 2016/1305). As this is a register-linked study, the approval also covers exemption from informed consent because that would not be feasible to acquire.
: All data generated or analysed during this study are included in this published article and its supplementary information files.
: This work is published under the standard license to publish agreement. After 12 months the work will become freely available and the license terms will switch to a Creative Commons Attribution 4.0 International (CC BY 4.0).