To assess whether antibiotics for common infections are prescribed in a risk-based manner and how this changed during the COVID-19 pandemic.


With the approval of NHS England, we accessed pseudonymised patient-level electronic health records of primary care data from The Phoenix Partnership (TPP) through OpenSAFELY. We included adults registered at general practices in England with a record of common infection, including lower respiratory tract infection (LRTI), upper respiratory tract infections (URTI), and lower urinary tract infection (UTI). Patients with a record of COVID-19 were excluded. Patient-specific risks of infection-related hospital admission were estimated for each infection cohort (not prescribed an antibiotic) using predictors. These predicted non-antibiotic risks were then applied to the antibiotic users and cohorts split into risk deciles.


We found 15,719,750 diagnoses of common infections from January 2019 to March 2023. Of them, 450,215 (2·86%) were hospitalised in the 30 days after the diagnosis and 10,429,060 (66·34%) prescribed an antibiotic. There were substantial differences in observed rates of hospital admissions between the lowest and highest risk deciles. The probability of prescribed antibiotic was unrelated for LRTI and UTI’s admission risks and weakly for URTI. During the COVID-19 pandemic, the level of risk-based antibiotic prescribing reduced. Predictors were not or only weakly associated with the probability of antibiotic prescribing.


There is a need to better target antibiotics in primary care to patients with worse prognosis and strengthen treatment guidelines in personalisation of prescribing.