From the *Department of Epidemiology, Bloomberg School of Public Health, and
†Department of Pediatrics, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, MD
Correspondence: Jacky M Jennings, PhD, MPH, Johns Hopkins University School of Medicine, Baltimore, MD. E-mail: firstname.lastname@example.org.
Received for publication October 15, 2018, and accepted October 21, 2018.