[1] University of California,Department of Family and Community Medicine
[2] University of California,Departments of Internal Medicine and Pediatrics
[3] San Francisco,Department of Sociology
[4] University of California,Departments of Medicine and Public Health Sciences
[5] Santa Cruz,The Philip R. Lee Institute of Health Policy Studies
[6] University of Chicago,undefined
[7] University of California,undefined
[8] San Francisco,undefined