1. a Department of Medicine , Johns Hopkins University School of Medicine , Baltimore , MD
2. b Center for Substance Abuse Prevention , Substance Abuse & Mental Health Services Administration , Rockville , MD
3. c Agency for Healthcare Research and Quality , Rockville , MD
4. d Department of Medicine , Oregon Health and Science University , Portland , OR
5. e Community Medical Alliance , Boston , MA
6. f Office of AIDS Research , National Institutes of Health , Bethesda , MD , US