pubmed-article:20117067 | pubmed:affiliation | Institute of Clinical Epidemiology, Medical Faculty, Martin-Luther-University of Halle-Wittenberg, Magdeburger Str. 8, 06097 Halle, Germany. andreas.stang@medizin.uni-halle.de <andreas.stang@medizin.uni-halle.de> | lld:pubmed |