1. Medical Practice Evaluation Center, Massachusetts General Hospital , Boston, Massachusetts , USA
2. Department of Medicine, Harvard Medical School , Boston, Massachusetts , USA
3. Africa Health Research Institute , Durban, Kwa-Zulu Natal , South Africa
4. Division of Infectious Diseases, Department of Medicine, Massachusetts General Hospital , Boston, Massachusetts , USA
5. Center for AIDS Research, Harvard University, Cambridge, Massachusetts , USA
6. Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital , Boston, Massachusetts , USA
7. Division of General Internal Medicine, Department of Medicine, Massachusetts General Hospital , Boston, Massachusetts , USA
8. Department of Health Policy and Management, Harvard T.H. Chan School of Public Health , Boston, Massachusetts , USA