Abstract Opioid deprescribing is recommended to reduce opioid-related harms; however, research suggests that opioid dose changes may lead to adverse health outcomes. We aimed to determine if opioid dose changes are associated with mental health–related or substance use–related emergency department (ED) presentations. This self-controlled case-crossover study used POpulation Level Analysis and Reporting (POLAR) primary care data linked with data from 3 metropolitan hospitals in Victoria, Australia. People who had a mental health–related or substance use–related ED (MHSU-ED) presentation between April 2018 and May 2022 and had received ≥4 opioid prescriptions in the 12 months preceding their ED presentation were included. Adjusted odds ratios (aOR) for MHSU-ED presentations were estimated using conditional logistic regression, comparing opioid dose change in the 30 days before MHSU-ED presentation to that in 5 corresponding sets of control periods of equal length not immediately preceding MHSU-ED presentation. Of the 1458 eligible patients, 75.9% experienced a >25% reduction in their prescribed opioid dose in the 30 days before MHSU-ED presentation. Compared with receiving no opioid prescriptions in the 30 days prior, a >25% reduction in prescribed opioid dose (aOR: 1.78; 95% confidence interval CI: 1.44-2.21) or opioid discontinuation (aOR: 2.04; 95% CI: 1.48-2.82) was linked to higher odds of a MHSU-ED presentation whilst a 10% to 25% reduction (aOR: 0.15; 95% CI: 0.10-0.23) or a stable or increased dose (aOR: 0.01; 95% CI: 0.008-0.022) was associated with lower odds of MHSU-ED presentation. Larger opioid dose reduction or discontinuation is associated with increased risk of subsequent mental health–related and substance use–related ED presentations.
Jung et al. (Wed,) studied this question.