Antibiotic Use in Patients with Medically-Attended Acute Respiratory Illness

James Bychinski
James Bychinski
University of Wisconsin

James Bychinski, Maria Sundaram, Huong McLean, Edward Belongia
Center for Clinical Epidemiology and Population Health

Research area: Epidemiology 

Background: Acute respiratory illnesses (ARI) are a significant cause of morbidity. Outpatient ARIs are often treated with antibiotics regardless of etiology. We analyzed secular trends and identified factors associated with antibiotic prescribing among patients with medically attended viral ARI.

Methods: We used data from patients enrolled in influenza vaccine effectiveness studies from 2007-08 through 2012-13. ICD-9 codes were used to determine illness characteristics described as viral etiology. Secular trends in antibiotic prescribing were analyzed using Cochran-Armitage tests for trend. Associations between demographic/illness characteristics and antibiotic prescribing were assessed using chi-square tests. Logistic regression with stepwise selection was used to identify factors associated with antibiotic prescribing. Separate models were built for children and adults.

Results: Of 1189 children with viral illness, 239 (20%) received an antibiotic. Of 1852 adults with a viral illness, 939 (51%) received an antibiotic. For both adults and children, there was a statistically significant increasing trend in antibiotic use from 2008-2010; from 2011-2013, antibiotic use significantly decreased. In children, age, duration of illness, wheezing, study year, lack of confirmed influenza infection, and insurance type were associated with an increase in odds of antibiotic prescribing. In adults, age, duration of illness, study year and influenza vaccination were associated with increased odds of antibiotic prescribing. Clinical department in which the patient was seen, race, and gender were not associated with receipt of an antibiotic prescription in either children or adults.

Conclusion: Trends in antibiotic prescribing for viral diagnoses have not remained stable over time. Factors associated with antibiotic prescribing for viral illnesses differed between children and adults. More research is needed on the relationship between ICD-9 codes and illness etiology.