Impact of an antibiotic side chain-based cross-reactivity chart combined with enhanced allergy assessment processes for surgical prophylaxis antimicrobials in patients with beta-lactam allergies.

BACKGROUND: Beta-lactam antibiotics are first line therapy for perioperative prophylaxis; however, patient-reported allergies often lead to increased prescribing of alternative antibiotics that may increase the incidence of surgical site infections. The R-group side chain of the beta-lactam ring is responsible for allergic cross-reactivity and experts recommend the use of beta-lactams that are structurally dissimilar. METHODS: An internally developed, antibiotic side chain-based cross-reactivity chart was developed and implemented alongside enhanced allergy assessment processes. This single center, quasi-experimental study analyzed antibiotic prescribing in all adult patients with a documented beta-lactam allergy undergoing an inpatient surgical procedure between Q1 2012 - Q3 2014 (historical group) and Q3 2016 - Q3 2018 (intervention group). Propensity-weighted scoring analyses compared categorical and continuous outcomes. Interrupted time-series analysis further analyzed key outcomes. RESULTS: A total of 1,119 and 1,089 patients were included in the historical and intervention cohorts, respectively. There was a significant difference in patients receiving a beta-lactam alternative antibiotic between cohorts (84.9% vs. 15.1%; p < 0.001). There was a decrease in 30-day readmissions in the intervention cohort (7.9% vs. 6.3%; p = 0.035); however, there was no difference in the incidence of SSIs in patients readmitted (14.8% vs. 13%; p = 0.765). No significant differences were observed in allergic reactions (0.5% vs. 0.3%; p = 0.323), surgical site infections, in-hospital and 30-day mortality, healthcare facility-onset Clostridiodes difficile infection, acute kidney injury, or hospital costs. CONCLUSION: Implementation of an antibiotic cross-reactivity chart combined with enhanced allergy assessment processes significantly improved the prescribing of beta-lactam antibiotics for surgical prophylaxis.