1. Cecil G. Sheps Center for Health Services Research; University of North Carolina at Chapel Hill; 725 Martin Luther King Jr. Blvd Chapel Hill NC 27599-7590 USA
2. School of Social Work; University of North Carolina at Chapel Hill; Rm 228-E 301 Pittsboro St, 3550 Chapel Hill NC 27599-3550 USA
3. School of Public Health, Management, Policy and Community Health; University of Texas; Austin TX USA
4. Fielding School of Public Health; University of California Los Angeles; 650 Charles E. Young Dr. South, 31-299D CHS Mail Code 177220 Los Angeles CA 90095-1772 USA