Use of influenza antiviral agents by ambulatory care clinicians during the 2012-2013 influenza season

Abstract

Background: Early antiviral treatment (≤2 days since illness onset) of influenza reduces the probability of influenza-associated complications. Early empiric antiviral treatment is recommended for those with suspected influenza at higher risk for influenza complications regardless of their illness severity. We describe antiviral receipt among outpatients with acute respiratory illness (ARI) and antibiotic receipt among patients with influenza.

Methods: We analyzed data from 5 sites in the US Influenza Vaccine Effectiveness Network Study during the 2012-2013 influenza season. Subjects were outpatients aged ≥6 months with ARI defined by cough of ≤7 days' duration; all were tested for influenza by polymerase chain reaction (PCR). Medical history and prescription information were collected by medical and pharmacy records. Four sites collected prescribing data on 3 common antibiotics (amoxicillin-clavulanate, amoxicillin, and azithromycin).

Results: Of 6766 enrolled ARI patients, 509 (7.5%) received an antiviral prescription. Overall, 2366 (35%) had PCR-confirmed influenza; 355 (15%) of those received an antiviral prescription. Among 1021 ARI patients at high risk for influenza complications (eg, aged <2 years or ≥65 years or with ≥1 chronic medical condition) presenting to care ≤2 days from symptom onset, 195 (19%) were prescribed an antiviral medication. Among participants with PCR-confirmed influenza and antibiotic data, 540 of 1825 (30%) were prescribed 1 of 3 antibiotics; 297 of 1825 (16%) were prescribed antiviral medications.

Conclusions: Antiviral treatment was prescribed infrequently among outpatients with influenza for whom therapy would be most beneficial; in contrast, antibiotic prescribing was more frequent. Continued efforts to educate clinicians on appropriate antibiotic and antiviral use are essential to improve healthcare quality.

Keywords: ambulatory care; antiviral treatment; influenza; neuraminidase inhibitors.

Figure 1.

Flow diagram of data from the US Influenza Vaccine Effectiveness Network and contributing antiviral medication and influenza data to 2012–2013 analysis. Abbreviation: PCR, polymerase chain reaction.

Figure 2.

The proportion of antiviral medication prescriptions to patients with acute respiratory infection enrolled ≤2 days since illness onset by influenza infection status, 2012–2013 influenza season, US Influenza Vaccine Effectiveness Network, 2012–2013. *Clinicians at this site had access to study-related influenza polymerase chain reaction testing results, which may have influenced prescribing patterns. No information was available as to nonstudy influenza testing performed at this site and others. Abbreviation: PCR, polymerase chain reaction.

Figure 3.

Comparing the proportion of patients with acute respiratory infection presenting ≤2 days since illness onset who received an antiviral prescription during the 2011–2012 and 2012–2013 influenza seasons, US Influenza Vaccine Effectiveness Network. Includes 3 study sites (A, B, and D). 2011–2012 season: n = 1201; 2012–2013 season: n = 1404. *All higher risk includes those <2 or ≥65 years of age or who meet 1 or more of the other risk criteria, which puts them at higher risk for influenza complications [7]. **Other risk criteria include American Indian/Alaska Native/Pacific Islander, pregnant, or having a chronic underlying medical condition, which includes morbid obesity (body mass index ≥40 kg/m²).