(B-067) Assessing the Impact of COVID-19 Lockdown on Methadone and Buprenorphine Prescriptions in England: An Interrupted Time Series Analysis

Background: Supervised consumption of opioid agonist therapy (OAT) was required to treat patients with opioid use disorders (OUD). Lockdown in response to COVID-19 changed access to OAT to two weeks 'take-home doses' in England. The lockdown and adjustment of relevant guidance could exacerbate inequalities in OAT availability across practices with different socioeconomic status (SES).

Objectives: This study aims to evaluate the impact of the guidance change response to the COVID-19 lockdown on the prescribing of OAT (i.e., methadone and buprenorphine) and how the policy affected the prescribing in general practices across socioeconomic disparities in England.

Methods: This quasi-experimental study used practiced-level dispensing data from March 2019 to February 2022 from the English Prescribing Data (EPD) and socioeconomic deprivation from the 2019 Index of Multiple Deprivation (IMD) in England. General practices that prescribed methadone or buprenorphine for opioid dependence during the study period were included. The monthly number of Defined Daily Doses (DDDs) were quantified, and SES for each neighbourhood was measured by IMD decile. Interrupted time series analysis was used to evaluate the impact of COVID-19 lockdown in March 2020. A group-based trajectory model was used to explore the variance between practices, and conditional logistic regression was used to observe the association with SES.

Results: Overall, 4,273 general practices were included in the study. A significant level elevation (β2=473678.3, p=0.002) and slope decrease (β3=-46396.6, p=0.03) in the monthly number of DDDs of methadone, and a level elevation (β2=114041.9, p=0.002) but no change in slope (β3=298.7952, p= 0.983) in the monthly number of DDDs of buprenorphine were found after COVID-19 lockdown. Overall, 16.8% of practices were categorised into decreasing methadone dispensing during the COVID-19 lockdown, but for buprenorphine, practices were categorised into either increasing or maintaining. More deprived SES was associated with a lower chance of being categorised into the trajectory of increasing methadone dispensing (Odds ratio=0.86, 95% confidence interval: 0.75-0.99) but not for buprenorphine (Odds ratio=1.00, 95% confidence interval: 0.87-1.15).

Conclusions: The guidance change due to the COVID-19 lockdown increased the prescribing of methadone and buprenorphine in England. Deprived SES was associated with decreased dispensing of methadone. More research is needed to explore the reasons for the variance in the response to the change of OAT access between general practices from different SES areas and did the prescribing amount restored to the pre-lockdown period in each SES.