1. Global Health Section, Department of Public Health, University of Copenhagen, 1014 Copenhagen, Denmark
2. Department of Epidemiology Research, Statens Serum Institut, 2300 Copenhagen, Denmark
3. Section of Health Services Research, Department of Public Health, University of Copenhagen, 1353 Copenhagen, Denmark
4. Center for Medicine and Society, Albert-Ludwigs-Universität Freiburg, 79098 Freiburg, Germany