Funding for this research was provided by:
ATHLOS project (No 635316)
Received: 2 March 2020
Accepted: 28 May 2020
First Online: 8 June 2020
Ethics approval and consent to participate
: ATTICA study was approved by the Bioethics Committee of Athens Medical School. The study was carried out in accordance with the Declaration of Helsinki (1989) of the World Medical Association. All participants were informed about the study aims and procedures and provided written informed consent.
: Not applicable.
: Prof. Demosthenes Panagiotakos is a member of the editorial board of BMC Medical Research Methodology. Thomas Tsiampalis declares no conflicts of interest related to this research work.