1. Department of Family and Preventive Medicine; University of South Carolina School of Medicine; 3209 Colonial Drive Columbia South Carolina 29201 USA
2. South Carolina Revenue and Fiscal Affairs Office, Health and Demographics Section; Columbia South Carolina USA
3. Department of Epidemiology and Biostatistics; University of South Carolina Arnold School of Public Health; Columbia South Carolina USA
4. Economics Department, Moore School of Business, University of South Carolina; Columbia South Carolina USA
5. Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities; Atlanta Georgia USA