aAIDS Policy Research Center, University of California, San Francisco, San Francisco, CAbDepartment of Social Medicine, University of North Carolina School of Medicine, Chapel Hill, NCcDepartment of Medicine, University of California, San Francisco, School of Medicine, San Francisco, CAdHouston Center for Quality of Care and Utilization Studies, Houston, TXeInstitute for Health Policy Studies, University of California, San Francisco, San Francisco, CA