1. Hospital Pablo Tobon Uribe; Anesthesiology Department; Medellin Colombia
2. Institute for Work & Health; 481 University Avenue, Suite 800 Toronto ON Canada M5G 2E9
3. University Health Network; TWH-Comprehensive Pain Unit; 399 Bathurst St 4th Floor Toronto ON Canada M5T 2S8
4. Toronto Western Hospital Comprehensive Pain Program; Department of Medicine; 399 Bathurst Street Fell Pavillion 4F811 Toronto Ontario Canada M5T 2S8
5. Massachusetts General Hospital; Medical Practices Evaluation Center; 50 Staniford Street 9th Floor Boston MA USA 02114
6. University of Washington; Department of Anesthesiology and Pain Medicine; Box 356540 Seattle Washington USA 98195