About the Authors
School of Public Health, Division of Epidemiology, Human Genetics and Environmental Sciences, University of Texas at Dallas, Dallas, Texas, United States of America
University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
The Leonard Cheshire Disability and Inclusive Development Centre, Department of Epidemiology and Public Health, University College London, London, United Kingdom
Faculty of Information and Department of Health Policy Management and Evaluation, University of Toronto, Toronto, Canada
The authors have declared that no competing interests exist.
Conceived and designed the experiments: KS AS. Performed the experiments: KH ZS KS. Analyzed the data: BR BM KS. Wrote the paper: KS KH BR NEG AS.