Bacterial prevalence and antimicrobial prescribing trends for acute respiratory tract infections.

Abstract

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. 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. 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. 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.