COVID-19 Impact on Australian Patients with Substance Use Disorders: Emergency Department Admissions in Western Sydney before Vaccine Roll Out.

Background: In this study, we determined the impact of the COVID-19 pandemic on Western Sydney patients with substance use disorders (SUD) by comparing emergency department (ED) admission rates before and after the onset of the COVID-19 pandemic and before the rollout of COVID-19 vaccination. Methods: ED admission data for patients with SUD were retrieved from the local electronic medical record (eMR) on the hospital central database. ED data collected from 25 January to 25 July 2019 (before the COVID-19 pandemic) were compared with data from 25 January to 25 July 2020 (early pandemic). ED admission reasons were categorised based on the presenting complaints and ED diagnoses. Results: Despite an overall reduction in ED admissions during the early pandemic, compared to the pre-pandemic period, admissions for patients with SUD increased significantly (1.7% to 3.4%, p < 0.01). ED admission rates related to infection (0.05% to 0.12%, p < 0.01), local infection (0.02% to 0.05%, p < 0.01), trauma (0.06% to 0.12%, p < 0.01), alcohol (0.01% to 0.03%, p < 0.05), and other issues (0.06% to 0.10%, p < 0.05) increased significantly among Indigenous patients with SUD. ED admission rates related to drugs (0.12% to 0.39%, p < 0.01), infection (0.21% to 0.34%, p < 0.01), local infection (0.07% to 0.18%, p < 0.01), gastrointestinal (0.15% to 0.23%, p < 0.05), trauma (0.14% to 0.25%, p < 0.01), alcohol (0.36% to 0.74%, p < 0.01), and ‘other’ issues (0.47% to 0.91%, p < 0.01) increased significantly among non-Indigenous patients with SUD. Four cases of COVID-19 were reported among these patients. Conclusions: There was an increase in ED admissions for patients with SUD in the initial six months of the COVID-19 pandemic (before vaccine rollout), mainly for drugs, systemic infection, local infection, trauma, and alcohol-related reasons. Now that most people in New South Wales have been vaccinated against COVID-19, a further study is needed to quantify the effect of the pandemic on patients with SUD in the post-vaccine era.