High rate of drug overdose deaths among adults recently released from incarceration

The overdose death rate was highest immediately following release -- nine per cent of the deaths occurred in the first two days and 20 per cent within the first week.

The study, published in PLOS ONE, also found that three quarters of those who died of an overdose were under the age of 45.

"This is the first Canadian study to examine overdose mortality rates by matching incarceration records with coroner reports after release," said Dr. Nav Persaud, a scientist with the Li Ka Shing Knowledge Institute of St. Michael's and a family doctor with the hospital's Academic Family Health Team. "We were surprised at how high the fatal overdose rate was among those who were recently released from provincial custody -- almost 12 times higher than the general population."

The researchers obtained data from the Ontario Ministry of Community Safety and Correctional Services between 2006 and 2013 on the nearly 50,000 people released annually from Ontario provincial correctional facilities. Dr. Persaud and his team looked at incarceration release records with coroner reports in the Coroner's Information System to determine how many of these people died of drug overdoses within one year of their release.

"Previous research has speculated that the higher risk for overdose immediately following release can be attributed to periods of no or less frequent drug use while individuals are incarcerated," said Dr. Persaud. "Once released, these individuals may not realize that their tolerance has diminished and can accidentally overdose."

The study also found that the majority of the overdose deaths involved opioids and that in over half of these cases, there was a person present who could have intervened.

Dr. Persaud said that increasing education around and access to interventions like naloxone, which can reverse an overdose, could help prevent future overdoses -- especially in situations where another person is present and could administer the treatment.

"At least some of these deaths are preventable and there may be opportunities to prevent overdose deaths by supporting this vulnerable group--during incarceration and immediately following release," said Dr. Persaud. "Future research and policy should focus on immediate interventions such as directing people to treatment programs and providing better access to naloxone, drug substitution therapies and overdose prevention education."