1 Department of General Practice and Health Services Research, University Hospital Heidelberg, Heidelberg D-69115, Germany kayvan.bozorgmehr@med.uni-heidelberg.de.
2 Department of General Practice and Health Services Research, University Hospital Heidelberg, Heidelberg D-69115, Germany.
3 Institute of Medical Biometry and Informatics, University Hospital Heidelberg, Heidelberg D-69120, Germany.
4 Department of Epidemiology and International Public Health, School of Public Health, Bielefeld University, Bielefeld 33501, Germany.