1 Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, NC, USA; Department of Family Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, USA. Electronic address: Christine_Kistler@med.unc.edu.
2 Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, NC, USA; Department of Family Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, USA.
3 Cecil G. Sheps Center for Health Services Research, University of North Carolina at Chapel Hill, NC, USA; Schools of Social Work and Public Health, University of North Carolina at Chapel Hill, NC, USA.