Study: 88% of Americans cling to outdated 'finish antibiotics' advice

For decades, the message was simple and absolute: finish every antibiotic your doctor prescribes, even after you feel better. It appeared on posters in clinics, came from the mouths of physicians, and lodged itself so firmly in the American mind that it became almost a moral imperative—a sign of responsibility, of doing the right thing with your health. But medicine has moved on, and the public largely hasn't.

A new study published in Open Forum Infectious Diseases found that 88% of Americans still believe they must always complete a full antibiotic course, regardless of circumstance. The survey of 1,475 people across the country reveals a significant gap between what patients think they should do and what current medical evidence actually recommends. For many common infections, shorter courses of antibiotics work just as well as longer ones—and carry fewer risks of side effects.

The disconnect is most visible in how people respond to pneumonia treatment. Current guidelines recommend three to five days of antibiotics for pneumonia, a substantial reduction from older protocols. Yet when researchers asked survey participants whether they'd feel comfortable with that shorter duration or would prefer a week or longer, about 60% chose the extended course. The reason was consistent: they'd been told, repeatedly and authoritatively, that stopping antibiotics early was dangerous. Most had heard this directly from clinicians. Many had absorbed it from public health campaigns that, while well-intentioned, had calcified into dogma.

Alistair Thorpe, a research assistant professor of population health sciences at University of Utah Health and lead author of the study, frames this as a natural consequence of how medical guidance works. "Historically, there was very strong guidance by major health organizations and clinicians that you must always finish the course," he explains. "Now, we're seeing a growing body of evidence saying that that is not always the case. And oftentimes, shorter durations of antibiotics are as effective and safe as longer alternatives." The evidence is substantial: for many infections, the shorter course achieves the same outcome with less exposure to the drug and lower risk of adverse reactions.

There are exceptions. Tuberculosis, for instance, still requires extended treatment. But for respiratory infections, urinary tract infections, and other common bacterial illnesses, the science has shifted. The problem is that the public's understanding hasn't kept pace, and the gap matters. When patients distrust their doctor's recommendation to stop antibiotics early, they may either refuse to follow the new guidance or feel anxious about doing so—both outcomes that undermine the doctor-patient relationship and potentially compromise care.

The researchers argue that the solution lies not in abandoning public health messaging but in making it more honest about complexity. Rather than declaring that shorter or longer courses are universally better, doctors and public health campaigns should acknowledge that recommendations evolve as evidence accumulates. They should avoid overly simplistic claims and instead engage patients in conversations tailored to their specific situation.

Thorpe's recommendation to patients is direct: ask your doctor about the appropriate duration for your particular infection and when you should stop. "Getting advice directly from a clinician on a one-to-one basis about what is most appropriate for you in that situation is the right way to go," he says. He emphasizes that the shift in guidance is not a failure of medicine but evidence of its success—a sign that doctors are learning more and adjusting practice accordingly. The challenge now is making sure that learning reaches the people taking the pills.