Accurate identification of opioid overdose deaths using coronial data

Area of Science:

• Forensic Toxicology
• Public Health Surveillance
• Mortality Auditing

Background:

• Drug-related mortality definition is complex, encompassing diverse diseases and circumstances.
• Fatal opioid toxicity deaths require precise identification for accurate public health assessment.
• Coronial data offers a valuable resource for investigating causes of death.

Purpose of the Study:

• To develop and outline a method for accurately identifying deaths directly resulting from fatal opioid toxicity.
• To improve the specificity and capture rate of opioid overdose deaths using coronial data.
• To explore the utility of coronial information beyond toxicology for understanding overdose circumstances.

Main Methods:

• Utilized the National Coronial Information System (NCIS), an Australian online coronial database.
• Developed methods to identify opioid overdose deaths by analyzing Medical Cause of Death, toxicology, clinical, and police investigation data.
• Compared different data sources within the NCIS for accuracy in identifying opioid overdose fatalities.

Main Results:

• Using Medical Cause of Death in coronial findings enhanced the identification of opioid overdose deaths.
• Distinguishing heroin from pharmaceutical opioid (e.g., morphine) deaths required integrating clinical and investigative data with toxicology.
• One-quarter of morphine-attributed deaths were reclassified as heroin-related after further investigation, indicating underestimation.
• Codeine-related deaths were also subject to some underestimation.
• Coronial data provided insights into comorbidities like chronic pain, substance use, and mental health issues.

Conclusions:

• Sole reliance on toxicology underestimates heroin-related overdose deaths.
• Differentiating pharmaceutical opioid from illicit opioid overdose deaths has significant policy implications for prescribing and harm reduction.
• Understanding comorbidities is vital for developing targeted interventions to reduce preventable opioid overdose deaths.