(210) Long-term prescribed opioid use after hospitalisation or emergency department presentation among opioid-naïve adults in New South Wales (NSW), Australia (2014–2020)—a population-based cohort study

Background: Opioids initiated for acute pain, particularly post-surgery, can be a precursor to long-term use, increasing the risk of opioid-related harm. There is limited Australian evidence on opioid use following hospitalisation.

Objectives: To describe opioid initiation and long-term use after emergency department (ED) visits or hospitalisations, by patient, admission and clinical characteristics .

Methods: Retrospective population-based cohort study, based on all hospitalisations and ED visits between 2014-2020 in NSW, linked to medicine dispensings, deaths and cancer registrations. Participants were >=18 years with no opioid dispensings in the previous year. Outcome measures were: opioid initiations (an opioid dispensing within 7 days of discharge) and long-term use (90 days of continuous opioid exposure in the period 90–270 days after initiation). We calculated the proportions of admissions resulting in opioid initiation and long-term use, stratified by patient, admission and clinical characteristics, age–sex standardised using model-based direct standardisation.

Results: The cohort included 16 153 096 admissions by 4.2 million opioid-naïve adults; 39.0% were ED presentations without hospital admission, 16.8% hospital admissions via ED and 44.2% direct hospital admissions. Opioids were initiated post-discharge for 6.20% of ED (95% CI 6.18–6.22), 8.32% of hospital via ED (95% CI 8.28–8.35) and 9.97% of direct hospital admissions (95% CI 9.94–10.01); of these 0.99% (95% CI 0.96–1.20), 2.46% (95% CI 2.39–2.53) and 0.54% (95% CI 0.52–0.56) progressed to long-term opioid use, respectively. Initiation was lowest in obstetric admissions without surgery (1.00%, 95% CI 0.97–1.03), and highest among trauma admissions (25.41%, 95% CI 25.27–25.55), obstetric admissions with surgical intervention (19.84%, 95% CI 19.64–20.03), non-trauma surgical admissions (11.99%, 95% CI 11.96–12.03), and ED presentations without subsequent admission (6.20%, 95% CI 6.18–6.22). Long-term use was highest among medical admissions via ED (3.46%, 95% CI 3.33–3.59), trauma admissions (2.29%, 95% CI 2.21–2.37) and ED alone (0.99%, 95% CI 0.96–1.02) and low after obstetric admissions with or without surgical intervention ( < 0.5%). Overall, opioid initiations decreased a relative 16% from 8.7% in 2014 to 7.2% in 2020; long-term opioid use decreased a relative 33% from 1.3% in 2014 to 0.8% in 2020.

Conclusions: Both opioid initiation and long-term use decreased over time. Nonetheless, the higher rates of long-term use following trauma and medical admissions via ED warrant monitoring and surveillance. Strategies supporting appropriate prescribing and access to multidisciplinary pain services will facilitate best-practice care.