Antibiotics Could Be Wrongly Prescribed in Tens of Millions of U.S. Cases, Scientists Warn

Scientists fear antibiotics may have been wrongly prescribed in tens of millions of cases in the U.S., amid the growing threat that the drugs may soon stop working.

A study using data from 2015 revealed as many as two fifths of prescriptions could have been inappropriate. That amounts to an estimated 23.7 million instances where the healthcare providers offered the medicine without providing a reason. The drugs were wrongly given in 32 million cases.

The research published in the journal The BMJ drew on the 2015 National Ambulatory Medical Care Survey, which featured information on 28,332 healthcare visits in the U.S. outside hospitals. This was scaled up to represent an estimated 990.9 million visits across the country that year.

A prescription was deemed appropriate if the clinician had mentioned a bacterial infection or condition for which antibiotics are always used. Prescriptions were labelled inappropriate in instances where the drugs weren't necessary. They fell into the "no documented indication" category if neither of the other groups applied.

Of the estimated 130.5 million prescriptions made that year, antibiotics were prescribed in 13.2 percent of cases. 57 percent of prescriptions appeared to be appropriate, 25 percent inappropriate, while 18 percent didn't give a reason. That totalled to an estimated 23.7 million antibiotic prescriptions without a documented indication in 2015, the researchers said.

The authors wrote: "We observed that approximately 24 million U.S. ambulatory care visits with antibiotic prescriptions lacked a documented indication in 2015. Taken with the 32 million prescriptions that we identified as inappropriate, as many as 43 percent of prescriptions in our dataset were potentially inappropriate."

They stressed: "Inappropriate prescribing of antibiotics is a major public health problem, as it contributes to antibiotic resistance."

The World Health Organization describes the trend as "one of the biggest threats to global health, food security, and development today," and worsened by the misuse of drugs.

Prescriptions written to adult males, and by dermatologists, urologists, gynecologists, and ear, nose, and throat specialists, and involving certain types of antibiotics were less likely to have a corresponding documented indication in the medical chart, the researchers found.

Patients who spent more time with the provider were more likely to be given a prescription without a documented reason, the data showed. Those who saw their regular doctor were meanwhile less likely to receive a prescription without an indication.

Study co-author Michael Ray of Oregon Health and Science University, Portland State University School of Public Health, told Newsweek: "This is a major proportion of prescriptions for which we cannot assess appropriateness."

Pointing out an "important" limitation of the study, Ray said: "We used nationally-representative, publicly-available survey data, which is great. However, the amount of information provided in this dataset is fairly limited. We only had access to five diagnosis codes per visit. It is possible that we would see a documented reason for the prescription if more information was available, such as more diagnosis codes or provider notes."

Enrique Castro-Sanchez is postdoctoral researcher at the Health Protection Research Unit in Healthcare Associated Infection and Antimicrobial Resistance at the U.K.'s Imperial College London, and did not work on the study. He told Newsweek: "This is an excellent study that uses methods and data that could be replicated by other researchers in other settings, and which highlights a crucial area for improvement not just in the U.S., but worldwide."

Due to the methods used, it was not possible to learn why such suboptimal prescribing took place, said Castro-Sanchez. "Other studies such as interviews and observation of physician-patient interactions could address such gap," he said.

Castro-Sanchez said members of the public should "reflect upon their contribution to antibiotic usage."

They can engage in decisions about the need to use antibiotics with health care providers, without pressuring them to prescribe the drugs.

He advised against buying antibiotics online "without the advice of a suitably qualified professional." Readers should also ensure their vaccinations are up-to-date, and avoid sharing leftover antibiotics with others, he said.