Ethical approval
The trial design and performance were approved by the following Norwegian committees: Regional Committee for Ethical Medical Research (REK, South-East C S-09269c 009/5419, date 29.4.2009), the Norwegian Social Science Data Services (21617, date 26.5.2009), and the Norwegian Medicines Agency, NoMA (EudraCT 2007–001778–10, date 9.4.2009). The trial was registered June 2009 (ClinicalTrial.gov NCT00921700).