aDepartment of Clinical Epidemiology, Aarhus University Hospital
bDepartment of Epidemiology, Institute of Public Health, Aarhus University, Aarhus, Denmark
cDepartment of Human Genetics and Teratology, National Centre for Epidemiology, Budapest, Hungary
dDepartment of Epidemiology, Boston University School of Public Health, Boston, Massachusetts, USA
Correspondence and requests for reprints to Dr Vivian Langagergaard, MD, Department of Clinical Epidemiology, Aarhus University Hospital, Ole Worms Allé 150, DK-8000 Aarhus C, Denmark
Tel: +45 8942 4800 or +45 8942 4818; fax: +45 8942 4801;
e-mail: [email protected]
Sponsorship: This work was supported by the Danish Cancer Society, the Danish Cancer Research Foundation, the Western Danish Research Forum for Health Sciences, Ingeborg and Leo Dannins Foundation for Scientific Research, Frits, George and Marie Cecilie Glud's Foundation, and Else and Mogens Wedell-Wedellsborg's Foundation.
There are no conflicts of interest.
Received 14 July 2006 Accepted 17 October 2006