1. RAND Health Care, Santa Monica, CA, USA
2. Department of Social & Behavioral Sciences, Indiana University Richard M. Fairbanks School of Public Health, Indianapolis, IN, USA
3. Parent Project Muscular Dystrophy, Hackensack, NJ, USA
4. RAND, Santa Monica, CA, USA
5. RTI International, Research Triangle Park, NC, USA
6. Department of Medicine, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
7. Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities, Atlanta, GA, USA