Funding for this research was provided by:
Helse Vest (NA)
Bergen Medisinske Forskningsstiftelse (NA)
GlaxoSmithKline (Norway) through the Norwegian Respiratory Society (NA)
the Endowment of timber merchant A. Delphin and wife through the Norwegian Medical Association (NA)
Text and Data Mining valid from 2019-08-14
Received: 11 March 2019
Accepted: 31 July 2019
First Online: 14 August 2019
Ethics approval and consent to participate
: The study was approved by the Regional Committees for Medical and Health Research Ethics (REK-Nord, case # 2011/1307) and was conducted in accordance with the Declaration of Helsinki. All study subjects signed informed consent forms.
: Not applicable.
: CD, HGW, TK, EN: The authors declare that they have no competing interests.TME: Reports bursary from Boehringer Ingelheim for educational meetings within the last three years, unrelated to the current study.RN: Reports grants from GlaxoSmithKline, during the conduct of the study; grants from Boehringer Ingelheim, grants and personal fees from AstraZeneca, grants from Novartis, grants from Boehringer Ingelheim, personal fees from GlaxoSmithKline, outside the submitted work.