1. Division of Vascular and Endovascular Surgery, Department of Surgery, Boston Medical Center, Boston, MA, USA
2. Division of Vascular Surgery, Department of Surgery, Warren Alpert Medical School of Brown University, Providence, RI, USA
3. Southern Connecticut Vascular Center, Stratford, CT, USA
4. Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
5. Division of Vascular Surgery, Department of Surgery, VA Boston Healthcare, West Roxbury, MA, USA