1. Department of Emergency Medicine and Schaeffer Center for Health Policy and Economics; University of Southern California; Los Angeles California
2. Pardee RAND Graduate School; Santa Monica California
3. U.S. Social Security Administration Office of Retirement and Disability Policy; Washington District of Columbia
4. Center for Patient Safety and Quality Research; Boston Children's Hospital; Boston Massachusetts
5. Department of Environmental Health; Boston University, School of Public Health; Boston Massachusetts