Antibiotic prescribing patterns by age and sex in England: why we need to take this variation into account to evaluate antibiotic stewardship and AMR selection

Objectives The drivers of antimicrobial resistance (AMR) likely vary substantially by different demographics. However, few complete open national detailed data exist on how antibiotic use (ABU) varies by both age and sex. Methods Here, prescriptions of antibiotics from General Practices in England for 2015-2023 disaggregated by 5-year age bands and sex were analysed at the national and Integrated Care Board (ICB) level. From a total of 249,578,795 prescriptions (across 9 years), 63% were given to women and the most prescribed were amoxicillin, nitrofurantoin and flucloxacillin sodium. Prescriptions per 100K population varied substantially across sex, age, geographical region, season, year, COVID-19 pandemic period and drug. Results Most antibiotics were prescribed more to women across most age bands (84% of antibiotics had more prescriptions to females across 50% of age bands). We show how this variation requires a more nuanced approach to comparing ABU across geographies and highlight that AWaRe targets are not met uniformly (young men have a higher proportion of Watch antibiotic prescriptions). We also show the impact on ABU of time-sensitive interruptions, including differential age-targeted influenza vaccination, COVID-19 restrictions and a shortage of amoxicillin combined with a Streptococcus A outbreak. Comparing to open access AMR data (MRSA in bloodstream infections) highlights the complexity of the link between ABU and AMR. Conclusions These detailed differences in ABU across England suggest that there should be large variation in AMR burden by age and sex, which now need to be quantified with detailed open access AMR data for a better intervention design.