1. Department of Biomedical Informatics, Vanderbilt University Medical Center , Nashville, TN 37203, United States
2. Kaiser Permanente Washington Health Research Institute , Seattle, WA 98101, United States
3. Center for Drug Evaluation and Research, US Food and Drug Administration , Silver Spring, MD 20903, United States
4. Harvard Pilgrim Health Care Institute , Boston, MA 02215, United States
5. Department of Biostatistics, Epidemiology and Informatics, University of Pennsylvania , Philadelphia, PA 19104, United States
6. Department of Medicine, Indiana University School of Medicine , Indianapolis, IN 46202, United States