1. Division of General Internal Medicine and Sheps Center for Health Services Research, University of North Carolina at Chapel Hill; UNC Sheps Center for Health Services Research, Suite 208, Campus Box 7590, Chapel Hill, NC 27599-7590
2. Department of Psychology, University of California, Riverside
3. Department of Family Medicine, School of Nursing, University of California, Los Angeles
4. Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles
5. Department of Family Medicine, University of California, Los Angeles