Bacterial Prevalence and Antimicrobial Prescribing Trends for Acute Respiratory Tract Infections

BACKGROUND AND OBJECTIVES: Antimicrobials are frequently prescribed for acute respiratory tract infections (ARTI), although many are viral. We aimed to determine bacterial prevalence rates for 5 common childhood ARTI - acute otitis media (AOM), sinusitis, bronchitis, upper respiratory tract infection, and pharyngitis-and to compare these rates to nationally representative antimicrobial prescription rates for these ARTI. METHODS: We performed (1) a meta-analysis of English language pediatric studies published between 2000 and 2011 in Medline, Embase, and the Cochrane library to determine ARTI bacterial prevalence rates; and (2) a retrospective cohort analysis of children age,18 years evaluated in ambulatory clinics sampled by the 2000-2010 National Ambulatory Medical Care Survey (NAMCS) to determine estimated US ARTI antimicrobial prescribing rates. RESULTS: From the meta-analysis, the AOM bacterial prevalence was 64.7% (95% confidence interval [CI], 50.5%-77.7%); Streptococcus pyogenes prevalence during pharyngitis was 20.2% (95% CI, 15.9%-25.2%). No URI or bronchitis studies met inclusion criteria, and 1 sinusitis study met inclusion criteria, identifying bacteria in 78% of subjects. Based on these condition-specific bacterial prevalence rates, the expected antimicrobial rescribing rate for ARTI overall was 27.4% (95% CI, 26.5%-28.3%). However, antimicrobial agents were prescribed in NAMCS during 56.9% (95% CI, 50.8%-63.1%) of ARTI encounters, representing an estimated 11.4 million potentially preventable antimicrobial prescriptions annually. CONCLUSIONS: An estimated 27.4% of US children who have ARTI have bacterial illness in the post-pneumococcal conjugate vaccine era. Antimicrobials are prescribed almost twice as often as expected during outpatient ARTI visits, representing an important target for ongoing antimicrobial stewardship interventions.