Impact of COVID-19 lockdown on methadone and buprenorphine prescriptions in England primary cares: an interrupted time series analysis.

BACKGROUND: The COVID-19 lockdown prompted changes in accessing opioid agonist therapy in England, but the lockdown and further adaptations could exacerbate inequalities in opioid agonist therapy availability across practices with different socioeconomic statuses. This study aimed to evaluate the impact of the COVID-19 lockdown on the prescribing of methadone and buprenorphine and how general practices located within areas with differing socioeconomic status responded to these policies in England. METHODS: This quasi-experimental study used a health administrative practice-level dispensing database from March 2019 to February 2022 and socioeconomic deprivation from the Office for National Statistics in England. General practices that prescribed methadone or buprenorphine were included. The monthly number of Defined Daily Doses (DDDs) and dispensed items were quantified. The monthly changes in DDDs and dispensed items during the COVID-19 lockdown were also calculated. Interrupted time series analysis was used to evaluate the impact of the COVID-19 lockdown in March 2020. For practices with consistent prescribing (any OAT prescribing from December 2019 to February 2020 and 6 months during the lockdown), a group-based trajectory model explored the variability between practices. RESULTS: A significant level elevation (β2 = 473,678.3, p = 0.002) and slope decrease (β3 = - 46,396.6, p = 0.03) in DDDs of methadone, and a level elevation (β2 = 114,041.9, p = 0.002) in DDDs of buprenorphine were found after COVID-19 lockdown. Practices located in the more deprived areas were more likely to prescribe OAT consistently, and 16.8% of practices were categorised into decreasing methadone dispensing during the COVID-19 lockdown, and 5.4% of practices were classified as increasing dispensing of buprenorphine. There was a tendency for practices located in deprived areas to be grouped into the trajectory of decreasing methadone dispensing, but not with buprenorphine. CONCLUSIONS: The COVID-19 lockdown limited the prescribing of methadone and increased the prescribing of buprenorphine in England. Further studies should adopt individual patient data to investigate the potential reasons for limiting the prescribing of methadone.