Comment: New research suggests antibiotic use may bear little association to clinical need. Instead, it can often be driven by other factors that have nothing to do with why a person is unwell.
Taking an antibiotic “just in case” can feel like a reasonable decision. But antibiotics only treat bacterial infections. If you don’t have a bacterial infection, an antibiotic won’t help and it can lead to harm. That’s because every exposure to an antibiotic increases the chances of resistant bacteria developing and multiplying. These bacteria can then spread between people, animals, and the environment, making future infections more difficult to treat.
A study in The Lancet Public Health provides a clearer picture of the scale and nature of this problem. Drawing on health data, the authors estimated the quantity of antibiotics needed in 186 countries. They then compared these estimates with reported antibiotic use in 67 countries where usage information was available.
Nearly three quarters of the 67 countries used more antibiotics than the researchers estimated were needed. Worryingly, 66 used more antibiotics from the World Health Organization’s ‘watch’ group than estimated as optimal. Antibiotics in this group are broad-spectrum drugs that come with a greater risk of causing antibiotic resistance and should generally be reserved for defined infections.
The study also found some higher-income countries used substantially more antibiotics than their infection burden appeared to justify. In contrast, lower-income regions often carry greater burdens of serious infection and resistance, while lacking access to effective antibiotics.
The findings are particularly relevant to New Zealand. Our antibiotic consumption is high compared with many other countries—we have the fourth-highest rate of antibiotic prescribing in the OECD.
Although our dispensing rates are dropping and resistance rates are still relatively low by international norms, resistance is increasing for some infections. High antibiotic use today risks eroding this favourable position.
What’s driving overuse?
Clinicians write antibiotic prescriptions during busy consultations, often before test results are available. A prescription can offer reassurance to a worried patient and apparent protection against the possibility that an illness will deteriorate.
Patients may also associate receiving medicine with receiving care. When someone is unwell, being told an antibiotic will not help can sound dismissive unless the clinician explains the likely cause of illness, offers ways to manage symptoms, identifies warning signs that symptoms may be worsening, and provides realistic options for care.
The health system shapes these conversations. Short appointments favour quick decisions. Poor continuity of care makes “watchful waiting” harder. Delays in accessing care may also lower the threshold for prescribing because neither patient nor clinician can be confident that reassessment will occur promptly.
This places a greater onus on patients to quiz their health professional and ask: “Is this illness likely to be bacterial?”, “What can I do to manage the symptoms?”, and “What warning signs mean I should seek help again?” When a clinician recommends watchful waiting or a delayed prescription, ask how long symptoms are expected to last and when the plan should change.
The key message for all of us is to only take antibiotics when needed and follow instructions on use. Never share medicines or use antibiotics left over from an earlier illness, particularly those kept in the back of the medicine cabinet “just in case” you get sick again.
Why antimicrobial stewardship matters
Antibiotic use not only affects the person taking these drugs but everyone who may later depend on their effectiveness. The drugs underpin surgery, cancer treatment, organ transplants, and treatment of common infections. Resistance threatens each of these areas.
Antimicrobial stewardship is the coordinated effort to ensure antimicrobials (antibiotics, antivirals, antifungals, and antiparasitic medicines) are used only when clinically necessary, and that the right medicine, dose, route, and duration are chosen.
Applying good stewardship practices is crucial. A person with a serious bacterial infection needs prompt access to an effective antibiotic. A person with a viral infection does not benefit from one.
Preventing the spread of infection is also part of stewardship. Vaccination, hand hygiene, safer sex, careful food preparation, and staying away from vulnerable people while infectious reduce the number of illnesses requiring treatment. These actions may appear mundane, but fewer infections mean fewer opportunities for antibiotics to be used and resistance to develop.
More broadly, antibiotic use in animals, plants, and the environment forms part of the resistance problem. Resistant bacteria do not respect boundaries between hospitals, communities, farms, food systems, and waterways. New Zealand has recorded reductions in veterinary and horticultural antibiotic sales. But this progress does not remove the need for vigilance. Instead, it highlights the value of surveillance, regulation, professional leadership, and sector accountability.
Preserving the effectiveness of antibiotics will require more than asking clinicians to prescribe less: patients, clinicians, health services, and policymakers each have roles in antimicrobial stewardship.
This article was originally published on Newsroom.
Tara Officer is a senior lecturer in the School of Health at Te Herenga Waka—Victoria University of Wellington.