Funding for this research was provided by:
Linköping University Library
Received: 6 March 2020
Accepted: 18 November 2020
First Online: 4 December 2020
Ethics approval and consent to participate
: The study was approved by the Research Ethics Committee at the Faculty of Health Sciences, Linköping University, Sweden (Dnr 2012/43-31) and The Research Ethics Committee at Athens University, Greece. All original research data will be stored for at least 10 years and will be available on request. All participant gave their written informed consent to participate including answering a questionnaire, and approval to have a small piece of hair cut from the back of the head.
: We declare that no competing interests exist.