Low prescription rate of drugs like methadone after opioid overdoses show improved care needed, say U of T researchers

Only one in 18 people who go to the emergency department or end up in hospital after an opioid overdose in Ontario are prescribed drugs like methadone or suboxone to help manage their substance use disorder, U of T researchers have found.

The study – published recently in the Canadian Medical Association Journal – looked at more than 47,000 emergency room visits or hospital admissions from January 2013 to March 2020.

The data from ICES examined the health care experiences of approximately 14,000 patients who sought treatment from hospital for opioid toxicity.

After analyzing the data, researchers concluded that “despite slight increases over time, [opioid agonist therapy] initiation rates after an emergency department visit or hospital admission for opioid toxicity in Ontario were low, with only one in 18 events leading to filling an [opioid agonist therapy] prescription within a week of discharge.”

Opioid agonist therapy (OAT) is the clinical practice of prescribing drugs like methadone or suboxone to help people with an opioid use disorder minimize their cravings and lower their physical withdrawal symptoms.

Researchers say the low prescription rate of drugs like methadone or suboxone to help people manage their opioid use disorder is a missed opportunity for harm reduction.

“We now know that only about four per cent of hospital encounters for opioid overdose led to OAT initiation. These low rates show that we need to improve care and access to treatment,” says Tina Hu, an assistant professor with the Temerty Faculty of Medicine’s department of family and community medicine, who was involved in the study.

Researchers also found that although the initiation rate of OAT increased over time in the study population, reaching more than five per cent of all patients seen in hospital by 2020, the process of starting OAT remained low overall.

“Our research shows that there were substantial disparities in OAT initiation rates, with potential barriers to prescribing for older patients, those with mental health diagnoses and those in the lowest neighbourhood income quintile,” said the study.

The missed opportunity to start OAT was especially striking given that the study noted that in about 22 per cent of cases, people who were part of the study population had an outpatient visit within seven days of their hospital visit.
“These results highlight critical missed opportunities to prevent future mortality and morbidity related to opioid use, despite connection to health care for many patients in the days after a toxicity event,” says the study.

The study also noted that a 2018 call by the Canadian Research Initiative in Substance Misuse to use “buprenorphine/naloxone as the preferred first-line treatment for [opioid use disorder] when possible” did not appear to lead to an increase in initiation rates.

“The release of a national guideline advocating for buprenorphine–naloxone as first-line therapy did not appear to substantially influence OAT initiation rates, suggesting that additional efforts are needed to improve initiation of OAT in acute care settings,” said the study.

Grants from the Canadian Institutes for Health Research supported this research.