Overdoses of opioid drugs are a major cause of emergency hospital admissions and preventable death in many countries. In Massachusetts, annual opioid-related overdose deaths have exceeded motor vehicle deaths since 2005, so several strategies have been introduced to tackle this growing problem.

For example, overdose education and naloxone distribution (OEND) programs train drug users, their families and friends, and potential bystanders to prevent, recognize, and respond to opioid overdoses. OEND participants are trained to recognize signs of overdose, seek help, rescue breathe, use naloxone (a drug that reverses the effects of opioid overdose), and stay with victims.

From 1996 to 2010, over 50,000 potential bystanders were trained by OEND programs in the United States, resulting in over 10,000 opioid overdose rescues, but their impact on death rates and hospital use has not been examined in controlled studies.

A team of researchers from Boston Medical Center (BMC), Boston University Schools of Medicine (BUSM) and Public Health (BUSPH) in collaboration with the Massachusetts Department of Public Health (MDPH), set out to evaluate the impact of OEND programs between 2006 and 2009.

They analysed annual opioid-related overdose deaths, emergency department and acute hospital use from 2002 to 2009 in 19 Massachusetts communities with high levels of opioid overdose where there was no, low and high OEND implementation.

After adjusting for factors such as age, sex, ethnicity, poverty, "doctor shopping" for prescription opioids, and addiction treatment, they found a significant reduction in opioid-related overdose deaths in communities where OEND was implemented compared with those where it was not. There appeared to be a dose-related impact, where the higher the cumulative rate of OEND implementation, the greater the reduction in death rates.

However, no significant differences in emergency department and acute hospital use were found. This, say the authors may be because the program encourages bystanders to engage the emergency medical system if they suspect an overdose.

"This study provides observational evidence that by training potential bystanders to prevent, recognize, and respond to opioid overdoses, OEND is an effective public intervention," they conclude.