Reviewed by S. Shaefer Spires, MD, Duke Center for Antimicrobial Stewardship and Infection Prevention
The authors performed a stepped wedge cluster randomized study of a 2-component antimicrobial stewardship intervention in 30 primary care practices in the University of Pennsylvania Healthcare System to improve antibiotic prescribing for respiratory tract diagnoses (RTD)1. The intervention components included one educational session on appropriate prescribing for respiratory tract infections per practice, followed by monthly electronic feedback to providers on their performance regarding antibiotic prescribing in RTDs. They classified the RTDs into 3 tiers based on the 2010-11 National Ambulatory Medical Care Survey published by the CDC in 2016.2 Tier 1 included those diagnoses for which antibiotics are almost always indicated, such as bacterial pneumonia, Tier 2 diagnoses were those where antibiotics “may be indicated” such as otitis media or acute sinusitis, and Tier 3 were those where antibiotics were “rarely indicated.” The provider reports consisted of individual and peer comparison feedback on the proportion of their visits with an antibiotic prescription for all RTDs and for each Tier of RTDs.
The stepped wedge cluster randomized design is a pragmatic study design that can be used to evaluate a clinical service or policy intervention implemented in subsequent clusters over time. In simple terms, the design is such that every cluster will serve as a control and intervention group at varying timepoints, and by the end of the study all clusters will have moved into the intervention group. With every cluster providing data during the control and experimental phases but at different times, this allows for a more robust evaluation for intervention and effect.
In this study, the primary care practices were randomized into 6 different clusters, starting in October 2017 after a 14-month baseline period, and included 183 providers and 185,755 unique office visits (127,324 pre vs 58,431 post). The proportion of all RTD visits with an antibiotic prescription decreased from 35.2% to 23.0% (P<.001). The effect was only seen in Tiers 2 and 3 RTDs. These results suggest the intervention reduced inappropriate antibiotic prescribing without adversely impacting appropriate prescribing. Notably, there were no changes in frequency of diagnoses or “diagnostic code shifting” observed after the intervention, suggesting there was not a noticeable shift to diagnosing more Tier 1 RTDs to game the system.
An interesting finding and possible limitation was the proportion of antibiotic prescriptions for tier 1 RTDs was 45% compared to 73.4% in tier 2. The authors ponder if this finding was the result of follow up visits carrying forward the previous visits diagnosis. It is also of interest that the diagnosis of sinusitis did not see any effects, suggesting there may be room for improvement here.
Overall, this is an important study, not only showing a significant improvement in antibiotic prescribing for RTDs but it also emphasizes the power of peer comparison. They used clinically relevant metrics, and utilized one of Robert Cialdini’s principles of influence, social proof; “we view an action as correct in a given situation to the degree that we see others performing it.”
Dutcher L, Degnan K, Adu-Gyamfi AB, et al. Improving Outpatient Antibiotic Prescribing for Respiratory Tract Infections in Primary Care: A Stepped-Wedge Cluster Randomized Trial. Clinical Infectious Diseases. 2022;74(6):947-956. DOI: 10.1093/cid/ciab602
Fleming-Dutra KE, Hersh AL, Shapiro DJ, et al. Prevalence of Inappropriate Antibiotic Prescriptions Among US Ambulatory Care Visits, 2010-2011. JAMA. 2016;315(17):1864-1873.