1. Section of General Internal Medicine, Clinical Addiction Research and Education Unit, Boston Medical Center, Boston, MA, USA
2. University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
3. Boston University Aram V. Chobanian & Edward Avedisian School of Medicine, Boston, MA, USA
4. Department of Community Health Sciences, Boston University School of Public Health, Boston, MA, USA
5. Opioid Overdose Prevention Pilot Program, Massachusetts Department of Public Health, Boston, MA, USA