Christine Layton, PhD, MPH¹, Jacqueline Amoozegar, MSPH², Patrick Nerz, BA², Carol Stanwyck, MEd, PhD³ and Karen Wooten, MA⁴, 1Division of Health Services and Social Policy Research, RTI International, Baltimore, MD, 2Division of Health Services and Social Policy Research, RTI International, Research Triangle Park, NC, 3NCIRD/ISD/Assessment Branch, Centers for Disease Control and Prevention, Atlanta, GA, 4Immunization Services Division, Centers for Disease Control and Prevention, Atlanta, GA