Antibiotic prescription rates for acute respiratory tract infections in US ambulatory settings

Abstract

Context: During the 1990s, antibiotic prescriptions for acute respiratory tract infection (ARTI) decreased in the United States. The sustainability of those changes is unknown.

Objective: To assess trends in antibiotic prescriptions for ARTI.

Design, setting, and participants: The National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey data (1995-2006) were used to examine trends in antibiotic prescription rates by antibiotic indication and class. Annual survey data and census denominators were combined in 2-year intervals for rate calculations.

Main outcome measures: National annual visit rates and antibiotic prescription rates for ARTI, including otitis media (OM) and non-ARTI.

Results: Among children younger than 5 years, annual ARTI visit rates decreased by 17% (95% confidence interval [CI], 9%-24%), from 1883 per 1000 population in 1995-1996 to 1560 per 1000 population in 2005-2006, primarily due to a 33% (95% CI, 22%-43%) decrease in OM visit rates (950 to 634 per 1000 population, respectively). This decrease was accompanied by a 36% (95% CI, 26%-45%) decrease in ARTI-associated antibiotic prescriptions (1216 to 779 per 1000 population). Among persons aged 5 years or older, ARTI visit rates remained stable but associated antibiotic prescription rates decreased by 18% (95% CI, 6%-29%), from 178 to 146 per 1000 population. Antibiotic prescription rates for non-OM ARTI for which antibiotics are rarely indicated decreased by 41% (95% CI, 22%-55%) and 24% (95% CI, 10%-37%) among persons younger than 5 years and 5 years or older, respectively. Overall, ARTI-associated prescription rates for penicillin, cephalosporin, and sulfonamide/tetracycline decreased. Prescription rates for azithromycin increased and it became the most commonly prescribed macrolide for ARTI and OM (10% of OM visits). Among adults, quinolone prescriptions increased.

Conclusions: Overall antibiotic prescription rates for ARTI decreased, associated with fewer OM visits in children younger than 5 years and with fewer prescriptions for ARTI for which antibiotics are rarely indicated. However, prescription rates for broad-spectrum antibiotics increased significantly.

Figure 1

National rates of ambulatory visits and antibiotic prescriptions, United States, 1995–2006 Footnote: ARTI, acute respiratory tract infections, ATB, antibiotics. White markers represent children aged <5 years, black markers represent persons aged ≥5 years. Error bars represent 95% confidence intervals. Data are from NAMCS and NHAMCS. Rates are average annual rates for each time period.

Figure 2

National rates of otitis media and non-otitis media ARTI visits, antibiotic prescriptions and proportion of visits resulting in antibiotic prescriptions, United States, 1995–2006 Footnote: ARTI, acute respiratory tract infections, ATB, antibiotics. White markers represent children aged <5 years, black markers represent persons aged ≥5 years. Error bars represent 95% confidence intervals. ARTI for which antibiotics are often indicated (Column B) included mastoiditis, sinusitis, pharyngitis, tonsillitis and non-viral pneumonia. ARTI for which antibiotics are rarely indicated (Column C) included acute nasopharyngitis, laryngitis, unspecified upper respiratory infection, bronchitis, bronchiolitis, viral pneumonia and influenza. Data are from NAMCS and NHAMCS. Rates are average annual rates for each time period.