Effectiveness of Direct Delabel of Allergy Labels in Type A Adverse Drug Reactions (ADRs) to Penicillin: A Multicentre Hospital-wide Prospective Cohort Study

Abstract

Background: Patient-reported penicillin allergy labels (PALs) are associated with adverse patient outcomes and inappropriate antibiotic prescribing. Removal of PALs via direct oral challenge (DOC) is associated with increased penicillin utilisation post.

Objectives: To assess the impact of direct delabeling (allergy label removal via medical reconciliation alone) of Type A ADR PALs on inpatient prescribing.

Methods: From January 2019 to December 2022 at two tertiary hospitals in Melbourne, patients aged ≥18 with Type A ADR PALs as defined by the validated Antibiotic Allergy Assessment Tool were offered direct delabeling or single-dose DOC. The primary endpoint was antibiotic use pre- and post-assessment (during index admission and 90-days post). The secondary endpoint was the proportion of patients delabeled in the direct delabeling and DOC cohorts in the electronic medical record at 90-days post assessment.

Results: 4108 allergy labels were assessed with 490 classified as Type A ADR PALs. 337 PALs were directly delabeled, 69 underwent DOC and 84 were not delabeled. There was increased use of any penicillin following direct delabeling (OR 19.19, 95% CI [2.48,148.36]) and DOC (OR 56.98, 95% CI [6.82,476.19]) during the index admission, higher in the DOC group compared with direct delabeling (OR 2.97, 95% CI [1.39,6.37]). Re-labeling at 90-days was low with no statistically significant difference between direct delabel (5/337, 1.5%) and DOC (0/69, 0%).

Conclusions: Both direct delabel and DOC of Type A ADR PALs increased penicillin usage, however the impact was greatest with DOC. Most patients remain delabeled at 90-days.