BACKGROUND The COVID-19 pandemic led to changes in delivery of opioid-agonist treatment (OAT) and risk of drug-related harm in Scotland. This study aimed to (i) examine changes in drug-related death (DRD) rates and the protective effect of OAT during the COVID-19 pandemic in Scotland (2020-2022) compared with the previous decade (2011-2019); and (ii) describe trends in OAT prescribing over the same period.

METHODS We conducted a retrospective cohort study using data from the Scottish national Prescribing Information System linked to healthcare and administrative data from Public Health Scotland. The cohort included individuals prescribed OAT (methadone or buprenorphine). We examined trends in OAT prescribing, calculated crude DRD rates per 1000 person-years, and used multivariable quasi-Poisson regression to estimate adjusted incidence rate ratios (aIRR) for DRD risk across four time periods (2011-2013, 2014-2016, 2017-2019, and 2020-2022).

RESULTS Between 2011 and 2022, 49,000 individuals accessed OAT, contributing 366,344 person years of follow-up, during which 5255 DRDs occurred. In the COVID-19 pandemic period (2020-2022), 34,241 people received OAT and there were 1825 DRDs. DRD rates increased steadily prior to 2020, but remained stable during the pandemic: the observed DRD rate during 2020-2022 was comparable to 2017-2019 (aIRR=0.96, 95 % CI=0.80, 1.15). Across all periods, being on OAT was consistently associated with a lower risk of DRD compared to being off treatment (aIRR=3.47, 95 % CI=2.98, 4.05).

CONCLUSIONS During the COVID-19 pandemic in Scotland, DRD rates remained stable following a three-fold rise since 2011-13. The protective effect of OAT was sustained during the pandemic, which highlights the importance of maintaining access to OAT during public health crises.