Funding for this research was provided by:
Landsforeningen for Hjerte- og Lungesyke (NA)
Norwegian Rheumatism Association (NA)
Marit Hansens Memorial Fund (NA)
Merck Sharp and Dohme (NA)
Odd Fellow Norway (NA)
Raagholt Foundation (NA)
Received: 19 March 2019
Accepted: 14 June 2019
First Online: 25 June 2019
Ethics approval and consent to participate
: This study was approved by the REK sør-øst B regional ethics committee (REC), which approved the study for all the hospitals involved (study reference number 2012/643/REK sør-øst B). REC granted permission to access records without obtaining consent from patients or their relatives due to the long duration of the study and late onset of the disease. REC also granted permission to obtain a control cohort (3:1) matched on age, sex, and geography from the CPRN.
: Not applicable.
: The authors declare that they have no competing interests.