Funding for this research was provided by:
Ella ja Georg Ehrnroothin Säätiö
Academy of Finland (266314, 31071)
Hengityssairauksien Tutkimussäätiö
Oulun Yliopisto
Jenny ja Antti Wihurin Rahasto
Article History
Received: 18 October 2019
Accepted: 27 December 2019
First Online: 15 January 2020
Ethics approval and consent to participate
: The FEAS study had been approved in 1997 by the Ethics Committee of the Finnish Institute of Occupational Health (where the Principal Investigator Dr MS Jaakkola was employed at the time of the data collection of FEAS) and the Ethics Committee of the Pirkanmaa Hospital District (approval number 97172 Jaakkola M). All participants gave an informed consent.
: Not applicable.
: The authors declare that they have no competing interests.