Dr. Boone is at the Centers for Disease Control, Atlanta, Georgia. Dr. Hay is at the Department of Pharmaceutical Economics and Policy, University of Southern California, Los Angeles, California. Dr. Aguanno is at the Department of Pathology, Baylor University Medical Center, Dallas, Texas. Dr. Getzen is at the Department of Risk, Insurance and Healthcare Management, Temple University, Philadelphia, Pennsylvania. Dr. Hortin is at the Clinical Pathology Department, National Institutes of Health, Bethesda, Maryland.