Consortia The members of the POC1B Study Group are Karsten Boldt, Elfride de Baere, Caroline C.W. Klaver, Frauke Coppieters, David A. Koolen, Dorien Lugtenberg, Kornelia Neveling, Jeroen van Reeuwijk, Marius Ueffing, Sylvia E.C. van Beersum, and Marijke N. Zonneveld-Vrieling.