[1] East Carolina Univ, Dept Surg, Brody Sch Med, Greenville, NC 27858 USA
[2] Univ South Carolina, Dept Epidemiol & Biostat, Arnold Sch Publ Hlth, Columbia, SC 29208 USA
[3] East Carolina Univ, Brody Sch Med, Greenville, NC 27858 USA
[4] Furman Univ, Dept Hlth Sci, Greenville, SC 29613 USA