1. Departments of Medicine and Biostatistics; Vanderbilt University School of Medicine; Nashville TN USA
2. Departments of Epidemiology and Medicine; Johns Hopkins University; Baltimore MD USA
3. Kaiser Permanente Northern California; Oakland CA USA
4. Harvard Medical School; Boston MA USA
5. British Columbia Centre for Excellence in HIV/AIDS; Vancouver BC Canada
6. University of Alabama at Birmingham; Birmingham AL USA
7. University of North Carolina; Chapel Hill NC USA
8. Alberta HIV Clinic; Sheldon M. Chumir Health Centre; Calgary AB Canada
9. Center for AIDS Research; University of Washington; Seattle WA USA