Additional Contributions: Nancy Linn, MFA, helped design the graphics for the medication instruction sheets. Jill Linnell, MPH, and Claudia Aristy, BA, assisted with instruction sheet development. Liang Yin, MS, developed the computer application. Stephanie DeFiores, MS, Meyling Oei, BA, and Neha Sathe, BA, were senior research assistants. We acknowledge Marc Gourevitch, MD, MPH, and Mark Schwartz, MD, who direct the Centers for Disease Control and Prevention/New York University Medicine and Public Health Research Fellowship Program, and Isabel Bazan, BA, Amy Chu, BS, Carolyn Cutler, BA, Michelle Diaz, BA, Leydi Espinal, BA, Giselle Jose, BA, Lindsay Katona, BA, Eric Levy, BA, Katherine Milligan, BA, Heidi Mock, BA, Susanna Silverman, BA, Margaret Wolff, BA, Julie Wytock, BS, and the staff of Bellevue Hospital's pediatric emergency department for their assistance with this study.