- Correspondence to Koenraad Cuypers, Nord-Trøndelag Health Study Research Center, Norwegian University of Science and Technology, Skjesol Østre, Åsenfjord 7632, Norway;
- Accepted 24 March 2011
- Published online 23 May 2011.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.