[1] Johannes Gutenberg Univ Mainz, Univ Med, Inst Med Biostat Epidemiol & Informat, D-55131 Mainz, Germany
[2] German Canc Res Ctr, Unit Environm Epidemiol C030, D-69120 Heidelberg, Germany
[3] Danish Canc Soc, Inst Canc Epidemiol, DK-2100 Copenhagen, Denmark
[4] Univ Bielefeld, Fac Publ Hlth, Dept Epidemiol & Int Publ Hlth, D-33501 Bielefeld, Germany