Impact of hospital formularies on fluoroquinolone prescribing in emergency departments.

OBJECTIVE: To examine factors associated with fluoroquinolone prescribing among adults receiving antibiotics for acute respiratory tract infections (ARIs) in emergency departments. STUDY
DESIGN: Cross-sectional.
METHODS: We analyzed data from 8 Department of Veterans Affairs medical centers and 7 nonfederal US hospitals. At each hospital, we randomly sampled 200 ARI visits with International Classification of Diseases, Ninth Revision discharge diagnoses for nonspecific upper respiratory infections, acute bronchitis, pharyngitis, sinusitis, and pneumonia between November 1, 2003, and February 29, 2004. Patient and provider factors associated with each visit were extracted from medical records. System characteristics were obtained by surveying pharmacy directors. Multivariable logistic regression was used to evaluate independent predictors of fluoroquinolone prescribing.
RESULTS: Fluoroquinolones accounted for 14% of these prescriptions. At hospitals with at least 1 unrestricted fluoroquinolone on formulary (n = 12), the average fluoroquinolone prescription rate was 17%, compared with a 6% prescription rate at hospitals where fluoroquinolone access was restricted by the hospital formulary (n = 3) (P < .0001). Factors associated with increased fluoroquinolone prescription rates were hospital admission (odds ratio [OR] = 1.8; 95% confidence interval [CI] = 1.1, 3.1) and the diagnoses of acute bronchitis (OR = 2.3; 95% CI = 1.3, 4.2), acute exacerbations of chronic bronchitis (OR = 2.6; 95% CI = 1.2, 5.6), and pneumonia (OR = 6.4; 95% CI = 3.3, 12.4). Restricted hospital status was associated with decreased fluoroquinolones accounted for 14% of the antibiotic prescriptions.
CONCLUSION: Hospital formulary policies represent a potentially important target for influencing outpatient drug prescribing in emergency departments.