1. Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
2. Institute of Health and Society, University of Oslo, Oslo, Norway
3. Primary Care Research Unit, Vårdcentralen Värmlands Nysäter, Värmland County, Sweden
4. Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, Massachusetts
5. Harvard-MIT Division of Health Science and Technology, Boston, Massachusetts