[1] Univ Calif San Francisco, AIDS Policy Res Ctr, San Francisco, CA 94105 USA
[2] Univ N Carolina, Sch Med, Dept Social Med, Chapel Hill, NC 27515 USA
[3] Univ Calif San Francisco, Dept Med, Sch Med, San Francisco, CA 94105 USA
[4] Houston Ctr Qual Care & Utilizat Studies, Houston, TX USA
[5] Univ Calif San Francisco, Inst Hlth Policy Studies, San Francisco, CA 94105 USA