1. Department of Anesthesiology, University of Minnesota , Minneapolis, Minnesota, USA
2. Department of Anesthesiology, Beth Israel Deaconess Medical Center, Harvard University , Boston, Massachusetts, USA
3. Ispine Pain Physicians , Maple Grove, Minnesota, USA
4. Department of Anesthesiology, Division of Pain Management, MD Anderson Cancer Center , Houston, Texas, USA
5. Department of Anesthesiology, University of Chicago , Chicago, Illinois, USA
6. Department of Community Dentistry and Behavioral Science, University of Florida , Gainesville, Florida, USA