2. Individuals dying of overdoses related to pharmaceutical opioids differ from individuals dying of overdoses related to other substances

Recently deaths involving pharmaceutical opioids have increased, and there are indications that these deaths often occur in a different sub-population than other overdoses. We investigated differences in characteristics of individuals who died from pharmaceutical opioid overdoses (POO) compared to all other overdoses (AOO).

Using the Norwegian Cause of death registry, we retrieved information on overdoses (ICD-10) and identified POOs (T40.2; T40.4) and AOOs (T40.X; T43.6) in 2010-2019. By linking data from nationwide registries, we analyzed data on opioid dispensations and the history of mental and behavioral disorders due to psychoactive substance use. 1224 persons were registered with POOs and 1432 persons with AOOs.

Individuals in the POO group were older and were more frequently women (35.0% vs 20.5%). They had higher prevalence of chronic pain (35.8% vs 13.2%), filled prescriptions of analgetic opioids more frequently the month before death (38.8% vs 12.0%) and used threefold higher doses of prescribed opioids compared to individuals in the AOO group (66 vs 26 oral morphine equivalents/day). In the POO group oxycodone and fentanyl were more frequently dispensed, while codeine and tramadol were more frequently dispensed in the AOO group. A lower proportion of those in the POO group had recorded diagnoses of substance use disorder compared to the AOO group.

Individuals overdosing on pharmaceutical opioids may not belong to the population who is targeted by existing prevention strategies, as they are more frequently older women with chronic pain using high doses of analgesic opioids.