Addressing Risk-Averse Prescribing Practices: A Hospital-Wide Initiative to Increase Cefazolin Use in Surgical Prophylaxis Using a COM-B Approach

Background/Objectives: Although cefazolin is the recommended antibiotic for surgical prophylaxis, patients with a penicillin allergy label (PAL) frequently receive second-line antibiotics due to misconceptions regarding β-lactam cross-reactivity. Despite robust evidence supporting risk-stratified cefazolin use, implementation remains inconsistent. We evaluated the effect of a behaviour-informed, multidisciplinary implementation strategy on appropriate cefazolin utilisation among PAL patients undergoing surgery. Methods: A before-and-after quality improvement study was conducted at Singapore General Hospital. Following revision of the institutional surgical prophylaxis guidelines, a hospital-wide implementation strategy informed by the Capability–Opportunity–Motivation Behaviour (COM-B) framework was implemented through clinician education, workflow redesign, point-of-care prescribing prompts, multidisciplinary governance and organisational endorsement. The primary outcome was the median weekly proportion of eligible PAL patients receiving cefazolin. Secondary outcomes included perioperative allergic reactions and surgical site infections (SSIs). Results: A total of 126 patients in the pre-intervention period and 133 patients in the post-intervention period were included. The median weekly proportion of PAL patients receiving cefazolin increased from 22% to 50% (p < 0.01), with sustained improvement throughout the intervention period. Three patients (2.3%) developed suspected allergic reactions following cefazolin administration; one reaction was mild (urticaria), one was moderate (rash and chest tightness without haemodynamic instability), and one was suspected anaphylaxis. Significantly, no cases resulted in intensive care admission or cancellation of surgery. No statistically significant difference in SSI incidence was detected between patients receiving cefazolin and those receiving alternative antibiotics (0/96 vs. 5/163, p = 0.161); however, the small number of events limits interpretation of this exploratory safety outcome. Conclusions: A behaviour-informed implementation strategy combining COM-B-guided intervention design, multidisciplinary governance and anaesthesiologist-led implementation was associated with a safe increase in cefazolin use for surgical prophylaxis in PAL patients. These findings suggest that interventions addressing behavioural and organisational barriers may support the implementation of evidence-based recommendations and improve cefazolin uptake in routine perioperative practice, although the impact on clinical outcomes requires further evaluation.