1. Department of Medicine, Perelman School of Medicine; University of Pennsylvania; Philadelphia PA USA
2. Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, and Center for Pharmacoepidemiology Research and Training, Perelman School of Medicine; University of Pennsylvania; Philadelphia PA USA
3. Medical Service, Corporal Michael J. Crescenz VA Medical Center; Philadelphia PA USA
4. VA Connecticut Healthcare System; West Haven CT USA
5. Yale University School of Medicine; New Haven CT USA
6. Philadelphia Field Initiating Group for HIV Trials; John Bell Health Center; Philadelphia PA USA
7. VA Greater Los Angeles Healthcare System and David Geffen School of Medicine; University of California Los Angeles; Los Angeles CA USA