Funding for this research was provided by:
Received: 4 October 2019
Accepted: 18 June 2020
First Online: 26 June 2020
Ethics approval and consent to participate
: The study protocol was approved by the Ethics Committee of Human Sciences at the University of Oulu (statement 6/2014). The participants were informed about the study and they gave their written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.