1. Department for Health Services Research, Division of Ethics in Medicine , Carl von Ossietzky University of Oldenburg , Ammerländer Heerstraße 114-118, 26129 Oldenburg , Germany
2. Friedrich-Alexander-University of Erlangen-Nuremberg, Institute of Sociology , Bismarckstraße 6, 91054 Erlangen , Germany
3. Friedrich-Alexander-University of Erlangen-Nuremberg, Institute of Sociology , Kochstraße 4, 91054 Erlangen , Germany