1. German Center for Neurodegenerative Diseases (DZNE); Witten North Rhine Westphalia Germany 58453
2. Witten/Herdecke University; School of Nursing Science; Stockumer Straße 12 Witten North Rhine Westphalia Germany 58453
3. University of Lübeck; Nursing Research Group, Institute of Social Medicine and Epidemiology; Ratzeburger Allee 160 Lübeck Germany D-23538