1 Dow Division of Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI, USA.
2 Survey Research Center, Institute for Social Research, University of Michigan, Ann Arbor, MI, USA.
3 Department of Health Management and Policy, University of Michigan School of Public Health, 2800 Plymouth Road, Bldg 16, Room 112 W, Ann Arbor, MI, 48109, USA.
4 Dow Division of Health Services Research, Department of Urology, University of Michigan Medical School, Ann Arbor, MI, USA. kinks@med.umich.edu.