Half of the antibiotics given without an infection noted

Another example would be the renewal of a prescription for someone taking antibiotics to treat acne, Linder said. But for the most part, he added, patients should be seen in the office before receiving an antibiotic.

Linder was due to present his findings Friday at IDWeek 2018, an annual meeting of infectious disease specialists in San Francisco. In general, studies presented at meetings are considered preliminary until they are published in a peer-reviewed journal.

Dr. Ebbing Lautenbach, head of the Division of Infectious Diseases at the University of Pennsylvania, agreed that the study could not show if all prescriptions were actually inappropriate. "But this certainly raises concerns that antibiotics are often prescribed for unclear reasons," he added.

Lautenbach said patients should feel free to ask questions when an antibiotic is prescribed. "Sometimes an antibiotic is an appropriate choice, and sometimes not.The providers should explain," Here's why I think an antibiotic is needed. "And there should be a discussion about the pros and cons of taking one," he suggested.

In addition to the public health problem related to antibiotic resistance, medications can also have side effects for anyone, such as nausea and diarrhea, and interactions with other drugs, Lautenbach noted.

Linder said his team was planning to "dive deeper" into their data to learn more about how doctors treat antibiotics.

For the moment, Linder said that there could be several reasons for doctors to prescribe an antibiotic even in the absence of accurate diagnosis of bacterial infection. Time constraints, for example, can cause some doctors to administer an antibiotic to a sore throat.

In some cases, Linder explained, a patient may require an antibiotic and the doctor gives up.

"But I think more often than not, the problem is the doctor's perception that patients want antibiotics," he said.

Linder suggested that patients play a more proactive role with regard to drugs.

"You can tell your doctor that you only want an antibiotic if it's really necessary," he said. "This will automatically change the doctor's default position."