PRINCIPLE trial demonstrates scope for in-pandemic improvement in primary care antibiotic stewardship

Background The Platform Randomised trial of INterventions against COVID-19 In older peoPLE (PRINCIPLE) trial has provided in-pandemic evidence of what does not work in the early primary care management of coronavirus-2019 disease (COVID-19). PRINCIPLE’s first finding was that azithromycin and doxycycline were not effective. Aim To explore the extent to which azithromycin and doxycycline were being used in-pandemic, and the scope for trial findings impacting on practice. Design and Setting We compared crude rates of prescribing and respiratory tract infections (RTI) in 2020, the pandemic year, with 2019, using the Oxford-Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC). Methods We used a negative binomial model including age-band, gender, socioeconomic status, and NHS region to compare azithromycin and doxycycline lower respiratory tract infections (LRTI), upper respiratory tract infections (URTI), and influenza-like-illness (ILI) in 2020 with 2019; reporting incident rate ratios (IRR) between years and 95% confidence intervals (95%CI). Results Azithromycin prescriptions increased 7% in 2020 compared to 2019, whereas doxycycline decreased by 7%. Concurrently, LRTI and URTI incidence fell by over half (58.3% and 54.4% respectively) while ILI rose slightly (6.4%). The overall percentage of RTI prescribed azithromycin rose by 42.1% between 2019 and 2020, doxycycline increased by 33%. Our adjusted IRR showed azithromycin prescribing was 22% higher in 2020 (IRR=1.22, 95%CI:1.19-1.26, p<0.0001), for every unit rise in confirmed COVID there was an associated 3% rise in prescription (IRR=1.026, 95%CI 1.024-1.0285, p<0.0001); whereas these measures were static for doxycycline. Conclusion PRINCIPLE trial flags scope for improvement in antimicrobial stewardship.