IMPACT of COVID-19 on the PRESCRIPTION of BIOLOGIC DMARDS: A POPULATION-LEVEL STUDY in ENGLAND

ABSTRACT

Background: There has been considerable uncertainty about the impact of biologic DMARDs (bDMARDs) on COVID-19 morbidity and vaccine efficacy, which may have influenced prescribing during the pandemic. Objectives: To assess trends in the prescription of three commonly used bDMARDs with different modes of action-adalimumab (ADA), rituximab (RTX) and tocilizumab (TOC)-in England before and during the COVID-19 pandemic. Methods: The National Health Service (NHS) Secondary Care Medicines dataset was utilised to analyse temporal trends in bDMARD prescriptions issued by all NHS hospital pharmacies in England. Monthly averages of prescriptions issued for ADA, RTX and TOC for combined indications, standardised using WHO Defned Daily Doses (DDD), were described from January 2019 to November 2021. Interrupted time-series analyses (ITSA) were used to estimate the effect of the pandemic on prescription trends for ADA, RTX and TOC;Newey-West standard errors with lags were used to account for autocorrelation between observation periods in these models. Results: Temporal trends in ADA, RTX and TOC prescriptions are shown in Figure 1. A 46% decrease in RTX prescriptions was observed between March and April 2020, from 1,338,300 DDD to 718,900 DDD, respectively, coinciding with the worsening COVID-19 pandemic in England. RTX prescriptions increased after May 2020, refected in the positive prescription trend observed in ITSA models (Table 1);however, RTX prescriptions remained below pre-pandemic levels, before decreasing again between November 2020 and February 2021. This coincided with increasing COVID-19 case numbers in England. For ADA, the pre-pandemic trend of increasing prescriptions continued during the pandemic, with no differences in prescription trends seen in ITSA models (Table 1). A 22% decrease in ADA prescriptions was observed between September and October 2020, from 2,037,800 DDD to 1,587,500 DDD, respectively, before rebounding to above pre-pandemic levels. Prescriptions for TOC increased during the pandemic, driven primarily by a 76% increase in prescriptions between December 2020 and January 2021, from 241,800 DDD to 425,000 DDD, respectively. Conclusion: Prescriptions for RTX in England halved during the early COVID-19 pandemic, and remain below pre-pandemic levels as of November 2021. This likely refects concerns about RTX use and increased COVID-19 mortality and reduced vaccine efficacy.1,2 In contrast, prescriptions for ADA have continued to increase during the pandemic, while prescriptions for TOC surged in December 2020, coinciding with the more widespread use of TOC for the treatment of severe COVID-19.