146 - Outpatient Antibiotic Stewardship in the COVID Era: Trends in antibiotic prescription in a statewide Veteran’s Affairs health care system

Background: Outpatient antibiotic stewardship is an emerging area of interest. The COVID-19 pandemic has led to unique restrictions such as social distancing and an increase in telemedicine visits. The effects on outpatient antimicrobial prescription needs further exploration.

Methods: We investigated the outpatient antimicrobial prescription trend pre (January 5 to March 14 2020) and post (March 15 to May 31 2020) COVID-19 restrictions at the Veteran’s Affairs Maryland Health Care System. We compared prescribing characteristics pre and post restrictions using Chi-squared and Mann Whitney U tests. Segmented regression analysis was used to compare antimicrobial prescriptions per 1000 encounters, with a control group from the same weeks in 2019.

Results: There were 3,881 total antibiotics prescribed for 382501 encounters during the 16 weeks in 2020. Post-restrictions, there was a significant decrease in encounters and antibiotics per week with mean difference of -15241 and -147, for encounters and antibiotics, respectively. The mean antibiotics per 1000 encounters was slightly higher in the post-restriction group, but without statistical significance by this analysis (10.1 vs 10.4, p-value 0.48). Other notable changes post-prescription described in the Table was a decrease in macrolide and an increase in trimethoprim-sulfamethoxazole; urgent care prescriptions decreased, while primary care prescription increased; and refill prescriptions were less common, while mail prescriptions were more common. On regression analysis, we found a significant level change of +2.7 antibiotics per 1000 encounters (p=0.02) immediately after restrictions were placed, without any significant change in trend (Figure). This translates to an additional 243 antibiotics prescribed during the post-restriction weeks. This was in comparison to data from 2019 which had no significant level or trend change during the same weeks.Table 1. Characteristics of antibiotics prescribed and comparison between pre and post COVID-19 restrictions in 2020, with 2019 control.
Figure 1. Segmented Regression of antibiotic prescription per 1000 encounters pre and post COVID-19 restrictions with 2019 as control group.


Conclusion: We found an immediate increase in antibiotics relative to encounters post COVID-19 restrictions though antibiotics and encounters were all generally decreased with azithromycin showing the most appreciable decrease. Further investigation is needed to understand these findings and the implications on the population.