Gauging cough duration can stem antibiotic overuse

Patients tend to underestimate how long a cough should last, leading to unnecessary use of antibiotics, according to a review of the evidence and a survey of patient beliefs.

The National Ambulatory Medical Survey in 2007 showed that there were 27 million outpatient visits for cough that year. That constitutes 25.3% of all family practice visits, said the University of Georgia College of Public Health, Athens. Half of patients received an antibiotic for their cough, and half the time, it was a broad spectrum antibiotic.

Often, cough is treated without evidence for antibiotics because the patient or doctor is uncomfortable with its duration.

Before patients ask how long a cough should last, they are likely to ask Google, he said. In his own Google search, he found estimates in a range of 7-14 days.

Surveyed Georgia residents by adding questions to the Georgia Poll conducted twice a year by the Survey Research Center at the University of Georgia. Almost 500 participated; 63% were women. It was an older population because the survey is conducted through land lines.

Participants were asked about their beliefs concerning antibiotics and the effectiveness of these drugs when the main symptom was a cough. They were asked how long they think it would take for the cough to get better if they were not taking any medicine; in six different scenarios: dry cough; coughing up yellow mucus or green mucus, or any of those kinds of cough with a slight fever, or no fever.

Patients with self-reported chronic lung disease or asthma were excluded from the survey.

Some respondents thought they would be better in as few as two days. Some thought the cough would last several months, but almost everyone thought it would take less than 2 weeks. There was not much difference between the scenarios, except when the scenario involved green phlegm.

Participants who had previously used antibiotics thought the cough would last longer, as did women, whites, and those with less education.

To determine how long a cough actually does last, a literature search was conducted. Focusing on studies in community-dwelling, otherwise healthy adults with undifferentiated acute cough or bronchitis, his colleagues narrowed the search to 18 studies. Five of those 18 provided useful data.

The mean duration was 17-18 days. “So now we know how long a cough lasts.”

Although the cough usually improves significantly in 2 weeks, most patients think it should be over in a week. And that’s a big driver, or may be a big driver, of antibiotic use.” It may also lead to patients seeking repeat visits after 4 days, or asking for a “better” antibiotic after 8 or 9 days, which results in more prescriptions for broad spectrum antibiotics.

His findings can be used to educate patients and physicians, and “create more realistic expectations about the duration of a cough [and] the duration of an acute illness.”