1. Center for Clinical and Genetic Economics, Duke Clinical Research Institute, Durham, North Carolina
2. Department of Medicine, Duke University School of Medicine, Durham, North Carolina
3. Outcomes Research and Assessment Group, Duke Clinical Research Institute, Durham, North Carolina
4. Department of Biostatistics and Bioinformatics, Duke University School of Medicine, Durham, North Carolina
5. Division of Cardiology, University of Maryland School of Medicine, Baltimore, Maryland