1 Department of General Practice/Family Medicine, University of Marburg, Karl-von-Frisch Str. 4, D-35043 Marburg, Germany. Electronic address: Norbert@staff.uni-marburg.de.
2 Department of General Practice/Family Medicine, University of Marburg, Karl-von-Frisch Str. 4, D-35043 Marburg, Germany.
3 Department of Knowledge Engineering & Bioinformatics, University of Marburg, D-35043 Marburg, Germany.