1. Center for Pain Research on Impact; Measurement and Effectiveness; Department of Anesthesiology and Pain Medicine; University of Washington; Seattle Washington
2. Division of Gerontology and Geriatric Medicine; Department of Medicine; University of Washington; Seattle Washington
3. College of Nursing and Health Sciences; University of Massachusetts; Boston Massachusetts
4. Division of General Medicine and Primary Care; Beth Israel Deaconess Medical Center; Harvard Medical School; Boston Massachusetts
5. Warwick Clinical Trials Unit; Warwick Medical School; University of Warwick; Warwick UK
6. Kadoorie Critical Care Research Centre; Nuffield Department of Orthopedics; Rheumatology and Musculoskeletal Sciences; University of Oxford; Oxford UK
7. Department of Epidemiology; University of Iowa; Iowa City Iowa
8. Department of Epidemiology and Public Health; University of Maryland; Baltimore Maryland