[1] Sanquin Res, Dept Donor Studies, Plesmanlaan 125, NL-1066 CX Amsterdam, Netherlands
[2] Vrije Univ Amsterdam, Ctr Philanthrop Studies, Amsterdam, Netherlands
[3] Univ Amsterdam, Acad Med Ctr, Dept Publ Hlth, Amsterdam, Netherlands
[4] Univ Amsterdam, Acad Med Ctr, Dept Social Med, Amsterdam, Netherlands
[5] Vrije Univ, Dept Sociol, Amsterdam, Netherlands