Despite years of recommendations from health authorities, far too few influenza patients at risk for severe illness are getting antiviral treatment, and too many may be receiving needless antibiotics, according to a new study led by the Centers for Disease Prevention and Control and Prevention (CDC).
During the 2012-13 flu season, the researchers found that among about 1,000 patients who had an acute respiratory illness (ARI) and were at risk for flu complications because of their age or other conditions, only 19% were prescribed an antiviral such as oseltamivir (Tamiflu) or zanamivir (Relenza).
They also found that only 16% of about 1,800 confirmed flu patients received antiviral treatment, while 30% of them received one of three common antibiotics. Their study was published online yesterday in Clinical Infectious Diseases.
The CDC recommends using antiviral (neuraminidase inhibitor) treatment in ARI patients who are at risk for flu complications, including those who are younger than 2 years or at least 65 years or have a chronic medical condition, even before test results are available. Treatment should start within 2 days after illness onset if possible, but later treatment can still help, the agency has said.
Five sites in five states
The research team, with the CDC’s Fiona Havers, MD, MHS, as lead author, analyzed data on 6,766 patients who were treated for an ARI at five outpatient clinics in Washington state, Wisconsin, Texas, Michigan, and Pennsylvania. The group included patients at least 6 months old who had a cough of no more than 7 days’ duration when seen. The clinics are affiliated with the US Influenza Vaccine Effectiveness Network.
All the patients were tested for flu by polymerase chain reaction, and the researchers examined their medical history and pharmacy records. In addition, four of the clinics gathered prescribing data on three common antibiotics (amoxicillin-clavulanate, amoxicillin, and azithromycin).
Of the 6,766 patients, 509 (7.5%) were given an antiviral prescription, the team found. Thirty-five percent (2,366) of the patients tested positive for flu, but only 355 (15%) of these were prescribed an antiviral.
The researchers identified 1,021 patients who were very clear candidates for antiviral treatment because they had confirmed flu, were at risk for severe illness because of age or other condition, and sought treatment within 2 days after they got sick. Of these, only 19% (195) were prescribed an antiviral.
The team also identified 1,825 confirmed flu patients for whom antibiotic data were available. Of these, 540 (30%) were given one of the three antibiotics, while 297 (16%) received antiviral treatment.
More education needed
“Antiviral treatment was prescribed infrequently among outpatients with influenza for whom therapy would be most beneficial; in contrast, antibiotic prescribing was more frequent,” the authors concluded. “Continued efforts to educate clinicians on appropriate antibiotic and antiviral use are essential to improve healthcare quality.”
The authors acknowledged that some of the antibiotics might have been appropriate for treating bacterial infections secondary to flu, but they said it is likely that most were unnecessary, potentially contributing to the growing problem of antibiotic resistance, according to a press release on the study from the Infectious Diseases Society of America (IDSA).
In an accompanying editorial, Michael G. Ison, MD, MS, of Northwestern University Feinberg School of Medicine in Chicago, says it’s concerning that the patients were seen at centers with expertise in flu research, where providers “should, theoretically, be more attuned to the importance of antiviral therapy, particularly in high-risk subjects.”
He adds that the study did not report on patients’ illness outcomes, so it’s not possible to assess the impact of failing to treat them with antivirals. He recommends that future studies include outcomes data for flu patients who do and do not receive antivirals, to help clarify the true benefits.
In other observations, Ison writes that the findings probably underestimate the overprescribing of antibiotics, because the study covered only three such drugs, omitting some that are often used to treat respiratory infections.
He also makes several recommendations for increasing the appropriate use of antivirals in flu patients, including expanding the use of newer diagnostic tests, given that documentation of flu infection increases the likelihood of antiviral therapy.