1. Division of Epidemiology and Community Health, School of Public Health, University of Minnesota, Minneapolis, Minnesota, United States
2. Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, Minnesota, United States
3. Department of Biostatistics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
4. Department of Epidemiology, University of Washington, Seattle, Washington, United States
5. Department of Medicine, University of Vermont, Burlington, Vermont, United States
6. Department of Pathology, University of Vermont, Burlington, Vermont, United States