Discussion

After one year of performing handshake stewardship on the medicine floor teams at a large teaching hospital with an existing stewardship program, there have been some important shifts in patterns of overall antibiotic use. While there was not a significant decrease in overall antibiotic use immediately following the implementation of the intervention, there has been a reversal of a trend of overall increasing antibiotic use that was statistically significant when the intervention effect was lagged by 3 months. Additionally, there were significant decreases in the use of specific broad-spectrum agents such as vancomycin and meropenem. Another important shift in usage patterns observed was the trend toward an increasing preference for oral agents as opposed to intravenous agents with the dDOT/tDOT metric. This may suggest that there were shifts toward more appropriate antibiotic use.

Unlike prior descriptions of handshake stewardship services, we did not find a statistically significant change in overall antibiotic use, which could be attributed to several factors. First, the size of the hospital and number of providers impacted the reach of our service and could have diffused the effects of any changes in antibiotic use. A high intensity stewardship service implemented in five internal medicine units at a 400-bed community hospital in Toronto demonstrated a reduction in overall antibiotic use from 483 to 442 defined daily doses/1,000 patient days. ^{Reference Langford, Brown, Chan and Downing7} Our study had 13 medicine units and >200 different providers some of whom were only on service a limited number of times over the year of the intervention thus impacting the reach of our intervention. Second, prior to this intervention, there was already an active antimicrobial stewardship program in place, and our starting antibiotic usage was slightly below the national average. ^{Reference Goodman, Cosgrove and Pineles13} Third, there is a significant proportion of antibiotic use driven by ID consult services, and handshake stewardship did not routinely review these antimicrobial regimens. The antibiotic use data was at the unit level; therefore, patients with ID consults were unable to be excluded from this outcome measurement. Fourth, the frequency of handshake stewardship rounds was only twice a week for medicine teaching services and once a week for hospitalist services. The Children’s Hospital of Colorado team, who pioneered handshake stewardship, started rounding three days per week but increased to five days per week after the first year and demonstrated a sustained decrease in overall antimicrobial use hospital wide after five years. ^{Reference MacBrayne, Williams and Levek1} The less frequent interaction in our study may have reduced the effect of the intervention. However, our acceptance rates compared favorably to prior studies describing this intervention. Seidelman et al. reported acceptance rates of 77.5% at one week, ^{Reference Seidelman, Turner and Wrenn6} whereas Hurst et al. reported acceptance rates of 86% at the end of the workday. ^{Reference Hurst, Child and Parker14}

Safety measures in stewardship studies are crude, but we saw no change in in-hospital mortality in the pre- and post-intervention period. We did see an unexpected increase in both length-of-stay and C. difficile infection rates in the studied period. The former likely reflects the overall secular trend of increasing lengths of stay that has been observed nationally since the onset of the COVID-19 pandemic, while the latter likely reflects a significant change in the C. difficile testing protocol implemented in 2022 (see supplementary discussion). ¹⁵

Stewardship interventions are difficult to generalize across different healthcare settings due to disparities in resources, tracking capabilities, baseline practice patterns, and regional microbiological profiles. While handshake stewardship is a resource-intensive intervention, the benefit of that upfront cost in effort is the inherent flexibility and adaptability of the intervention to specific contexts. Because of the personal and individual nature of the intervention, relationships between the stewardship team and multiple provider teams can be built and strengthened, which can then affect an overall shift in prescriber culture. These benefits are less tangible and difficult to track; however, the high intervention acceptance rate and enthusiastic provider survey feedback reflect these benefits. And indeed, following the initial enthusiastic response on the medicine floors, we expanded the intervention to the surgical floors and one of our ICUs. Based on the positive feedback from medical residents, we created a formal medical resident rotation, which has become popular. Handshake stewardship can also change with the institution—as patient populations, antibiograms, and institutional priorities shift, handshake stewardship teams can adapt in real time.

Limitations in this study stem in part from limitations in tracking capabilities. Only inpatient DOT were included in this analysis, and it is unknown whether the shorter durations recommended inpatient reliably translated to shorter outpatient durations. Second, our analysis was limited by waves of COVID surges that occurred through both the pre- and post-intervention periods, although we tried to account for this with some subgroup analysis excluding remdesivir. It has been shown that COVID surges are correlated with increased antibiotic use, which influenced our results. ^{Reference Dodds Ashley, Lokhnygina and Doughman16,Reference Barlam, Al Mohajer and Al-Tawfiq17} Third, we did not assess appropriateness or adherence with guidelines as part of this analysis.

In conclusion, adding a handshake stewardship team does endow additional benefits—both tangible, with shifts in antibiotic use patterns toward narrower and oral regimens, and less tangible benefits in changing overall hospital culture toward antibiotics by being a visible and accessible resource to help guide antibiotic use.