Table 2.

Variables and response options to be examined in association with pharmaceutical opioid-related emergency department presentations, by opioid-type

Category	Variable	Variable options
Patient demographics	Age	≥12 years; extracted in 5-year blocks
	Sex	Males, females, total (including other genders with cell sizes too small to be extracted separately)
	Region	Metro, regional/rural, interstate/overseas, unknown
	Country of birth	Australia, overseas (presented as an English speaking country, or non-English speaking country if cell sizes allow). The 12-month substance use disorder prevalence is 6% for Australian born residents, 4.4% if the birthplace was another English-speaking country, and 1.6% for a non-English speaking country.27
	Patient SEIFA	Socio-Economic Indexes for Areas (SEIFA) is a proxy measure for socioeconomic status based on home postcode.28 Australians living in the lowest socioeconomic areas have the highest burden of disease and highest rates of opioid prescriptions.2
Context of presentation (intent of use, indicator of misuse)	Human intent	i. Unintentional ii. Intentional self-harm iii. Assault, maltreatment and neglect iv. Other and undetermined intent
Admission outcome (proxy of severity)		i. Discharge to home/ returning to usual residence ii. Admission to ward/ procedure room—this campus (note, this is also a proxy for clinical severity) iii. Transfer to another hospital campus iv. Departure before treatment completed
Triage severity of presentation (proxy of severity)	Australasian Triage Scale (ATS) Category	Each of the five categories relates to treatment acuity and the maximum waiting time for medical assessment and treatment. i. ATS 1 (Immediate) ii. ATS 2 (10 min) iii. ATS 3 (30 min) iv. ATS 4 (60 min) v. ATS 5 (120 min)