25% of Antibiotic Prescriptions Are Unnecessary. Here’s Why That’s So Dangerous

The overuse of antibiotics is a growing problem. When used too frequently or inappropriately, the drugs can become ineffective for conditions they could normally treat since bacteria can develop resistance to them. As more bacteria are becoming resistant to all available antibiotics, there will be fewer, and sometimes not any, antibiotic options for people who might truly need them to control life-threatening infections.

Now, a new study published in the BMJ puts some hard numbers on just how often they’re overprescribed. Nearly 25% of the time, antibiotics are inappropriately prescribed, the study finds.

The study authors started by categorizing the more than 90,000 medical conditions in the standard diagnosis coding scheme, which doctors use to classify medication conditions for billing, into three categories: whether antibiotics are always, sometimes or never justified in the treatment of that condition. They then analyzed more than 15 million prescriptions for antibiotics filled by more than 19 million people in 2016 who filed claims for reimbursement through private insurance plans. They looked back three days before the prescription was filled to determine why the antibiotics might have been needed, and classified each prescription as appropriate if the conditions found always justified antibiotics, potentially appropriate if the conditions sometimes justified the drugs, and inappropriate if the condition never justified antibiotics.

The researchers found that 12% of the prescriptions filled by this group were appropriate, and 23% were inappropriate. About a quarter were also not connected to a recorded condition, which could mean that some of them were also inappropriate. Some antibiotic prescriptions were not even linked to a condition in the three-day period before the fill. (Some of that could have represented inappropriate prescribing, while some of it could indicate refills or even prescriptions paid out of pocket by people going to retail clinics, for example.)

“Our findings are striking,” says Dr. Kao-Ping Chua, an assistant professor of pediatrics at the University of Michigan Medical School, who led the study. “On a population level, one out of seven people in the study received at least one inappropriate antibiotic prescription during the year. That’s huge if you consider there are 320 million people in America.”

Chua notes that looking at the entire range of medical conditions that doctors diagnose provided a clearer picture of the extent to which antibiotics are prescribed inappropriately — for viral conditions, for example, when they can only treat bacterial ones. Previous studies looked only at certain conditions, such as upper respiratory infections, to gauge how frequently antibiotics were prescribed inappropriately for that condition.

The most common conditions for which antibiotics were inappropriately prescribed included acute bronchitis, upper respiratory infections and coughing — conditions for which the drugs wouldn’t be helpful, since they are caused by viruses rather than bacteria.

When he broke the prescriptions down by age, Chua found that antibiotics are prescribed inappropriately for adults (25% of cases) more than for children (17% of cases). That could mean that pediatricians are more careful about using the medications among children, but he also says that the data showed that 40% to 50% of the antibiotics prescribed for children were potentially appropriate — meaning that some of those prescriptions may not have been necessary or helpful.

The study highlights how rampant overprescribing and inappropriate prescribing of antibiotics still is, despite recent efforts to address the problem, Chua says. Some hospitals now rate doctors on how often they prescribe antibiotics, comparing them to their colleagues in an effort to prompt more rigorous consideration before they write a prescription. Digital programs that alert physicians when they are prescribing the drugs for inappropriate conditions also help to reduce the number of questionable prescriptions. But Chua says that the current health care system promotes the unnecessary use of antibiotics. “There are lots of factors that push us toward that,” he says. “There is fear of litigation in some cases, and other instances where patients won’t have good follow up, so it pushes you toward prescribing since it’s easy and it’s fast. We need a long-term culture change…if you don’t really need a prescription, it’s okay not to give it.”