Institutional Review Board Statement
All subjects gave their informed consent for inclusion before they participated in the study. The study was conducted in accordance with the Declaration of Helsinki, and the protocol was approved by the following ethics committees: METC van de stichting BEBO, Dr. Nassaulaan 10, 9401 HK Assen, The Netherlands (NL64202.056.17) 18th September 2018; Regional Committee for Medical and Health Research Ethics (South East) B), Gullhaugveien 1–3, 0484 Oslo, Norway (2018/436) on 20th September 2018; Tallinn Medical Research Ethics Committee, Hiiu 42, Tallinn 11619, Estonia (No 2532) on 15th November 2018; Vilnius regioninis biomedicininių tyrimų etikos komitetas, M.K.Čiurlionio g. 21, Vilnius, Lithuania (Nr. 2019/3–1106–604) on 26th March 2019 and Commissie voor medische ethiek, UZ Gent, C. Heymanslaan 10, B 9000 Gent, Belgium (2019/1928 BC-06481) on 6 March 2020.