Funding for this research was provided by:
Suomen Tuberkuloosin Vastustamisyhdistyksen Säätiö (-)
Hengityssairauksien Tutkimussäätiö (-)
the Competitive State Research Financing of the Expert Responsibility Area of Tampere University Hospital (-)
the Medical Research Fund of Seinäjoki Central Hospital (-)
Nummela Sanatorium Foundation (-)
Received: 4 February 2019
Accepted: 23 December 2019
First Online: 10 January 2020
Ethics approval and consent to participate
: The study protocol was approved by the Ethical Committee of Helsinki University Hospital, Finland (approval number 200/13/03/00/15). The subjects filled in a written informed consent form attached to the written questionnaire.
: Not applicable.
: The authors declare that they have no competing interests.