Patients with acute cough illness (ACI) believe symptoms should resolve somewhere between 5-9 days (depending on the scenario), though a systematic review of published literature shows the mean duration of a cough to be almost 18 days, according to researchers at The University of Georgia. This discrepancy may be causing patients to seek care and request antibiotics, researchers hypothesized.

“We know from clinical trials there is very little, if any, benefit to antibiotic treatments for acute cough because most of these illnesses are caused by a virus,” said Mark Ebell, MD, associate professor of epidemiology in the UGA College of Public Health. “Among patients who receive antibiotics, about half of those will be very broad spectrum antibiotics that have the potential to increase antibiotic resistance. These are antibiotics that would be nice to still have around when we actually need them, like for someone who may have pneumonia.”

For the study, Ebell performed a meta-analysis by looking at 19 observational studies that each included between 23 and 1,230 patients and took place in the U.S., Europe, Russia and Kenya. He used the placebo or untreated control groups to determine that acute cough illness actually lasts an average of 17.8 days.

To gauge patient expectations, questions about the length of time a person thinks they should suffer with a cough were added to the bi-annual Georgia Poll, a random digit dialing survey of 500 Georgia residents from the UGA Survey Research Center. The results found people expected an illness to have a median duration of 5 to 7 days and a mean duration of 7.2 to 9.3 days, depending on the specific scenario.

“Other researchers have found that previous experiences with antibiotics, having a chronic medical condition, and believing antibiotics are helpful for viruses predict a belief that antibiotics are helpful for ACI,” the authors concluded. “Our results are consistent with these previous findings, in particular the belief of patients with a chronic respiratory illness and among those who have previously received antibiotics in the efficacy of antibiotics.”