Ethics approval and consent to participate
POLAND
Each country obtained ethics approval prior to the commencement of the trial (Australia [Human Ethics Sub-Committee approval no. 1852845]; Germany [approval no. DGP 19-013]; Norway [Norwegian Centre for Research Data (Ref 502736) and Norwegian REK Medical and Research Ethics Ref 2019/941]; Poland [approval no. 186/KBL/OIL/2019]; UK Integrated Research Application System (IRAS) [approval no. 19/EE/0177]). Results will be disseminated in international peer-reviewed journal(s) and at scientific meetings. Informed consent was provided from all dyads.