1. Department of Surgical Sciences, Unit of Medical Epidemiology, Uppsala University , Uppsala , Sweden
2. Department of Medicine, University of North Carolina School of Medicine , Chapel Hill, NC , USA
3. Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina , Chapel Hill, NC , USA
4. Unit of Cardiovascular and Nutritional Epidemiology, Institute of Environmental Medicine, Karolinska Institutet , Stockholm , Sweden