1. Gopal K. Singh ( ) is a senior epidemiologist at the Maternal and Child Health Bureau, Health Resources and Services Administration, U.S. Department of Health and Human Services, in Rockville, Maryland.
2. Mohammad Siahpush is a professor in the Department of Health Promotion, Social and Behavioral Health, University of Nebraska Medical Center, in Omaha.
3. Michael D. Kogan is director of the Office of Data and Program Development, Maternal and Child Health Bureau, Health Resources and Services Administration.