1. Department of Family & Community Medicine, Wake Forest University School of Medicine,Winston-Salem, North Carolina,
2. Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University School of Medicine,Winston-Salem, North Carolina
3. Department of Family & Community Medicine, Wake Forest University School of Medicine,Winston-Salem, North Carolina
4. Department of Urology, Vanderbilt University Medical Center, Nashville, Tennessee
5. Department of Internal Medicine ,Wake Forest University School of Medicine,Winston-Salem, North Carolina