1. Department of Epidemiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
2. CTI Clinical Trials and Consulting, Inc., Covington, Kentucky, USA
3. Department of Medicine, Columbia University, New York, New York, USA
4. Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
5. Department of Preventive Medicine, Northwestern University, Chicago, Illinois, USA
6. Stony Brook University, Stony Brook, New York, USA
7. Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
8. Department of Medicine, University of Mississippi, Jackson, Mississippi, USA