1. Division of Overdose Prevention, National Center for Injury Prevention and Control, Centers for Disease Control and Prevention , Atlanta, GA 30341, USA
2. Immunization Services Division, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention , Atlanta, GA 30333, USA
3. Massachusetts Department of Public Health, Massachusetts Prescription Monitoring Program, Bureau of Health Professions Licensure , Boston, MA 02108, USA