1. Medical Practice Evaluation Center, Massachusetts General Hospital , Boston, Massachusetts , USA
2. Division of Infectious Diseases, Massachusetts General Hospital , Boston, Massachusetts , USA
3. Harvard Medical School , Boston, Massachusetts , USA
4. Harvard University Center for AIDS Research , Boston, Massachusetts , USA
5. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland , USA
6. Division of Pulmonary and Critical Care Medicine, Massachusetts General Hospital , Boston, Massachusetts , USA
7. Department of Medicine, Vanderbilt University School of Medicine , Nashville, Tennessee , USA
8. Department of Biostatistics, Vanderbilt University School of Medicine , Nashville, Tennessee , USA
9. Department of Medicine, Johns Hopkins School of Medicine , Baltimore, Maryland , USA
10. Division of General Internal Medicine, Massachusetts General Hospital , Boston, Massachusetts , USA