Current status and challenges in the assessment of antibiotic allergy information in electronic health records: a retrospective observational study of perioperative patients.

Background: Inappropriate antibiotic allergy labeling often leads to the unnecessary avoidance of first-line therapies. The present study aimed to evaluate the current status of antibiotic allergy documentation and its assessment in patients undergoing surgery for which cefazolin was the recommended first-line prophylaxis in a Japanese hospital. Methods: This retrospective observational study was conducted at a university hospital in Tokyo from 2021 to 2023; included patients with a history of antimicrobial allergy who underwent surgery for which cefazolin was recommended; and assessed patient demographics, details of the allergies in electronic health records (EHR), and perioperatively administered antimicrobial agents. Results: Of 2,402 eligible patients, 243 (10.1%) had a registered antimicrobial allergy. The drug classes most frequently recorded in the EHR were cephalosporins (25.0%) and penicillins (24.0%). Documentation of allergy assessments by a physician (9.0%) or specialist (7.0%) was rare. Although 51.9% of the labeled patients had received cefazolin, non-first-line agents had also been frequently administered. Notably, clindamycin had been administered to 30% of the cases and had been widely used even among patients with only a penicillin allergy label despite the low risk of cross-reactivity. Conclusions: Antibiotic allergy labels in the EHR were often incomplete, infrequently assessed, and associated with substantial avoidance of first-line prophylaxis. Redesigning the EHR format to allow allergies to be distinguished from adverse events while retaining the standard evaluation pathways is essential to optimizing perioperative antimicrobial stewardship.