1. Section of Vascular Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, NH
2. VA Outcomes Group, White River Junction, VT
3. Dartmouth Institute for Health Policy and Clinical Practice, Dartmouth Medical School, Hanover, NH
4. Section of Vascular Surgery, University of Utah, Salt Lake City, UT
5. Section of Vascular Surgery, Mayo Clinic, Rochester, MN