Comparing rates and characteristics of ambulance attendances related to extramedical use of pharmaceutical opioids in Victoria, Australia from 2013 to 2018

Abstract

Background and aims Despite increases in opioid prescribing and related morbidity and mortality, few studies have comprehensively documented harms across opioid types. We examined a population-wide indicator of extramedical pharmaceutical opioid-related harm to determine if the supply-adjusted rates of ambulance presentations, the severity of presentations or other attendance characteristics differed by opioid type. Design Retrospective observational study of coded ambulance patient care records related to extramedical pharmaceutical opioid use, Setting Australia Cases Primary analyses used Victorian data (n = 9823), with available data from other Australian jurisdictions (n = 4338) used to determine generalizability. Measurements We calculated supply-adjusted rates of attendances using Poisson regression, and used multinomial logistic regression to compare demographic, presentation severity, mental health, substance use and other characteristics of attendances associated with seven pharmaceutical opioids.Findings In Victoria, the highest rates of attendance [per 100 000 oral morphine equivalent mg (OME)] were for codeine (0.273/100 000) and oxycodone (0.113/100 000). The lowest rates were for fentanyl (0.019/100 000) and tapentadol (0.005/100 000). Oxycodone-naloxone rates (0.031/100 000) were lower than for oxycodone as a single ingredient (0.113/100 000). Fentanyl-related attendances were associated with the most severe characteristics, most likely to be an accidental overdose, most likely to have naloxone administered and least likely to be transferred to hospital. In contrast, codeine-related attendances were more likely to involve suicidal thoughts/behaviours, younger females and be transported to hospital. Supply-adjusted attendance rates for individual opioids were stable over time. Victorian states were broadly consistent with non-Victorian states. Conclusions In Australia, rates and characteristics of opioid-related harm vary by opioid type. Supply-adjusted ambulance attendance rates appear to be both stable over time and unaffected by large changes in supply.

Comparing rates and characteristics of emergency department presentations related to pharmaceutical opioid poisoning in Australia: a study protocol for a retrospective observational study

“…5 Similar research using Australian ambulance attendance data found that different pharmaceutical opioids have distinct patterns of harm. 6 For example, the highest rates of opioid-related ambulance attendance were accounted for by the lowest potency opioid, different opioids were associated with accidental overdoses versus suicidal Strengths and limitations of this study ► Indicator of population-level opioid harm. ► Cases have been selected using International Classification of Diseases 10th Revision (ICD) codes and free-text searches, increasing the capture of relevant cases over studies that use ICD codes alone.…”

“…13 Victoria's per capita rate for unintentional pharmaceutical-opioid induced deaths is comparable with other Australian jurisdictions, 14 and previous work demonstrated that Victorian rates of ambulance attendance for extramedical pharmaceutical opioid use were broadly consistent with other jurisdictions. 6 Australia has the eighth highest per capita licit pharmaceutical opioid consumption in the world. 2 This population-wide study has a catchment area of the entire Victorian state, for the past 10 years (July 2009-June 2019), for individuals aged 12 years of age and older.…”

“…Open access intent, and the availability and formulation of the opioid appeared important in explaining patterns of harm. 6 There is a need for further research to extend these findings with other datasets, and particularly to focus on the outcome of opioid poisoning. Opioid poisoning is also referred to as 'opioid overdose', and is an acute condition resulting from the absorption of excessive amounts of opioids into the body.…”

“…3 Although some studies have disaggregated results by heroin and pharmaceutical opioids, 10 few ED studies have differentiated between the individual pharmaceutical opioids involved. Relative harms with pharmaceutical opioids have been examined through coded ambulance attendances 6 ; however, there are many patients who self-present to the ED without the use of an ambulance service, and these patients may represent a unique population.…”

“…Tapentadol was introduced to the Australian market in 2011, subsidised in 2013 and is currently the fourth most commonly prescribed opioid in Victoria. 6…”