Published today in The Lancet Public Health, the international study introduces the first framework for estimating how much of each type of antibiotic individual countries need, providing policymakers with a practical way to improve antibiotic stewardship while ensuring patients have access to effective treatment.
Antimicrobial resistance (AMR) is one of the world's most pressing public health challenges. Using antibiotics appropriately is essential to slowing the development of resistance while ensuring people with bacterial infections can access the medicines they need.
To help guide antibiotic use, the World Health Organization (WHO) groups antibiotics into three categories through its AWaRe classification.
- Access antibiotics are recommended as first-line treatments for the most common bacterial infections and carry a lower risk of driving resistance.
- Watch antibiotics are broader-spectrum medicines that should be used more selectively because they have a greater potential to contribute to resistance.
- Reserve antibiotics are last-resort treatments for multidrug-resistant infections.
To understand how these antibiotics should be used across different health systems, the researchers behind the new study analysed data from 186 countries, territories and areas, representing 99.8% of the global population. They grouped countries with similar patterns of infectious disease, antimicrobial resistance, healthcare access and socioeconomic factors, then used benchmark countries with comparatively low antibiotic use and low infection-related mortality to estimate the optimal levels of Access, Watch and Reserve antibiotics needed to treat bacterial infections appropriately.
The study estimates that around 43 billion days of antibiotic treatment were required globally in 2019, equivalent to around one course of antibiotics per person each year. The researchers found that approximately 77% of antibiotic use should come from the WHO's Access group, suggesting the United Nations' target for at least 70% of antibiotic use worldwide to come from Access antibiotics by 2030 is appropriate.
Although higher-income countries currently use the most Watch and Reserve antibiotics, the study estimates that more than 80% of the world's optimal need for these medicines lies in lower-income countries, where infectious disease and antimicrobial resistance burdens are highest.
When the researchers compared these estimates with antibiotic use data from 67 countries, they found substantial differences between current practice and estimated need. Nearly three-quarters of countries (72%) were using more antibiotics overall than estimated to be necessary, while almost every country (99%) prescribed too many Watch antibiotics. The researchers also found that 60% of countries were still using antibiotics that the WHO considers should no longer be prescribed.
At the same time, 42% of countries were using fewer Access antibiotics than estimated to be needed, and more than half (52%) were not using enough Reserve antibiotics, which are essential for treating multidrug-resistant infections.
Lead author Aislinn Cook, Senior Research Fellow in Infectious Diseases Epidemiology at City St George's, University of London and DPhil student at the Nuffield Department of Primary Care Health Sciences, said:
"Our findings show the world faces a double challenge – while some antibiotics are being overused, millions of people may still lack access to the medicines they need to treat their infections.
"We have developed the first practical way for countries to estimate how much of each type of antibiotic their populations need based on infection burden and antibiotic resistance. This framework can help move the conversation beyond measuring antibiotic consumption to matching antibiotic use with public health need. This can support countries to develop more targeted policies to reduce overuse while ensuring sustainable access to effective antibiotics."
The findings also suggest that current global targets could be strengthened by combining them with country-specific estimates of antibiotic need. Rather than focusing only on the proportion of antibiotics prescribed from different groups, policymakers could use the new framework to make decisions that better reflect local patterns of disease and antimicrobial resistance.
Senior author Dr Koen Pouwels, Associate Professor in Health Economics at the Nuffield Department of Primary Care Health Sciences, said:
"Global targets such as aiming for 70% of antibiotic use to come from the WHO Access group are an important starting point, but they cannot tell countries how much of each AWaRe antibiotic group they actually need.
"By providing country-specific benchmarks, our work gives policymakers a practical way to move beyond percentage targets and make better-informed decisions about reducing overuse, improving access and strengthening antibiotic stewardship. Importantly, these benchmarks can become more ambitious over time if countries reduce infection burden, even in the face of demographic change."
The researchers say the framework could help governments better align antibiotic policies with public health needs by reducing unnecessary prescribing, improving access to essential antibiotics and ensuring that Reserve antibiotics are available for patients with life-threatening drug-resistant infections. They also highlight the importance of strengthening surveillance systems to better monitor antibiotic use and resistance over time, alongside improving access to quality-assured antibiotics and developing national targets that reflect local patterns of disease and antimicrobial resistance.
The study, ‘Estimating optimal levels of WHO Access, Watch, Reserve (AWaRe) antibiotic use in 186 countries, territories, and areas on the basis of clinical infection and resistance burden' was funded by the Wellcome Trust and is published in The Lancet Public Health.