The median duration of antibiotic courses for most common conditions, except acute cystitis, was 10 days, exceeding guideline-recommended durations in many cases, according to data published in Clinical Infectious Diseases.
Using minimum effective durations is a component of antibiotic stewardship. While unnecessary outpatient antibiotic prescribing is common, few studies have examined outpatient course durations. Investigators described the durations of antibiotic prescriptions for common bacterial infections leading to outpatient prescriptions.
Prescriptions for streptococcal pharyngitis, sinusitis, acute otitis media (AOM), community-acquired pneumonia (CAP), skin and soft tissues infection (SSTI), and acute cystitis were identified using the 2017 dataset from the National Disease and Therapeutic Index (NDTI; IQVIA, Plymouth Meeting, PA). In total, 2889 sampled antibiotic prescriptions met the study inclusion criteria, which translates to a national estimate of 31,548,464 (95% CI, 29,833,606-33,263,322) prescriptions. Only 28,016,314 (95% CI, 26,430,509-29,602,119) antibiotic prescriptions were included due to 11% (95% CI, 10-13%) of prescriptions being azithromycin, which has substantially different duration recommendations compared to other antibiotics.
The median antibiotic duration for each condition was 10 days, except for acute cystitis which was 7 days (interquartile range (IQR), 5-7 days). Investigators found 55% (95% CI, 53-58%) of antibiotic courses in this study exceeded guideline-recommended minimum effective durations, translating to 54,496,316 potentially excessive days of therapy. Seventy-six percent (95% CI, 71-77%) of antibiotic courses exceeded minimum guideline recommendations in adults, compared with 36% (95% CI, 33-39%) in children.
Investigators were unable to account for underlying conditions, previous treatment failures, and other factors that might warrant longer durations. Analysis was limited to antibiotic duration and assumed all antibiotics prescribed were warranted, which study authors believe is unlikely. In addition, the NDTI dataset may not be nationally representative as it uses proprietary methodology to estimate prescription weights. Furthermore, the dataset does not include non-private practice physician outpatient settings, where duration patterns may vary.
Investigators “found that clinicians frequently defaulted to 10-day durations even when guidelines recommend shorter durations, potentially exposing patients to unnecessarily long antibiotic therapy durations for many common conditions.” Compliance with recommended duration of antibiotic therapy could be improved specifically for sinusitis and CAP in adults, cellulitis in all ages, and acute cystitis in women 12 to 64 years. Investigators believe that increased focus on appropriate durations for common conditions could play a role in unnecessary outpatient antibiotic use.
King LM, Hersh AL, Hicks LA, Fleming-Dutra KE. Duration of outpatient antibiotic therapy for common outpatient infections, 2017. Published online September 16, 2020. Clin Infect Dis. doi:10.1093/cid/ciaa1404