Defining Appropriate Antibiotic Prescribing in Primary Care: A modified Delphi Panel Approach

Background: Antimicrobial overuse contributes to antimicrobial resistance. In the ambulatory setting, where more than 90% of antibiotics are dispensed, there are no Canadian benchmarks for appropriate use. This study aims to define the expected appropriate outpatient antibiotic prescribing rates for three age groups (<2, 2-18, >18 years) using a modified Delphi method.

Methods: We developed an online questionnaire to solicit from a multidisciplinary panel (community-academic family physicians, adult-paediatric infectious disease physicians, and antimicrobial stewardship pharmacists) what percentage of 23 common clinical conditions would appropriately be treated with systemic antibiotics followed with in-person meetings to achieve 100% consensus.

Results: The panelists reached consensus for one condition online and 22 conditions face-to-face, which took an average of 2.6 rounds of discussion per condition (range, min-max 1-5). The consensus for appropriate systemic antibiotic prescribing rates were, for pneumonia, pyelonephritis, non-purulent skin and soft tissue infections (SSTI), other bacterial infections, and reproductive tract infections, 100%; urinary tract infections, 95%-100%; prostatitis, 95%; epididymo-orchitis, 85%-88%; chronic obstructive pulmonary disease, 50%; purulent SSTI, 35%-50%; otitis media, 30%-40%; pharyngitis, 18%-40%; acute sinusitis, 18%-20%; chronic sinusitis, 14%; bronchitis, 5%-8%; gastroenteritis, 4%-5%; dental infections, 4%; eye infections, 1%; otitis externa, 0%-1%; and asthma, common cold, influenza, and other non-bacterial infections (0%). (Note that some differed by age group.).

Conclusions: This study resulted in expert consensus for defined levels of appropriate antibiotic prescribing across a broad set of outpatient conditions. These results can be applied to community antimicrobial stewardship initiatives to investigate the level of inappropriate use and set targets to optimize antibiotic use.