Penicillin Allergy Testing Is Cost-Saving: An Economic Evaluation Study

Abstract

A penicillin allergy label is associated with the use of less appropriate and more expensive antibiotics and increased health care use. Many patients with a penicillin allergy label do not have a true allergy and may be safely treated with penicillin. In this economic evaluation study, researchers sought to evaluate whether penicillin allergy testing would be cost-saving.In this study, researchers included patients with a penicillin allergy label. Input parameters were obtained from the scientific literature pooled by meta-analysis, administrative databases, and technical reports. Two alternative scenarios were compared: in the first scenario, patients were evaluated for penicillin allergy; in the second scenario, evaluation was not performed, with all patients being treated as penicillin allergic. Patients with history of a severe cutaneous reaction for whom reexposure or testing is contraindicated were excluded.By using Consolidated Health Economic Evaluation Reporting Standards guidelines, decision models were built to project whether penicillin allergy testing would be cost-saving. Costs of allergy testing, inpatient bed days, outpatient visits, antibiotic use, and diagnostic testing were considered in 2017 US dollars. A total of 24 base decision models were created, including inpatient and outpatient settings and geographic regions. Diagnostic workflows included sequential performance of skin testing and subsequent drug challenge (DC) or direct DC. Variants for each model were developed by using data from the United States, Europe, and Portugal. For each model, evaluation of penicillin testing under base case assumptions was performed. Additionally, the number of simulations identifying penicillin allergy testing as cost-saving were evaluated when the values of variables varied under a distribution of probabilities. Uncertainty was explored by using probabilistic sensitivity analyses.Penicillin allergy testing was cost-saving in all decision models built. For models including sequential skin testing and DC, the average incremental net benefit was $657 for inpatients and $2746 for outpatients. In probabilistic sensitivity analyses, penicillin allergy testing was identified as the less costly strategy in 70.2% of all simulations.Penicillin allergy testing was projected to be cost-saving across scenarios. Evaluation of reported penicillin allergy and effective delabeling of appropriate patients has economic advantages.In the current study, the authors suggest significant economic benefit associated with penicillin testing. Additional benefits that are less easily captured include system and patient benefits associated with risk avoidance from alternative antibiotics and therapies and benefits over a lifetime for patients who are not penicillin allergic and are successfully delabeled. The authors note that as many as one-half of patients with negative penicillin testing may not get correctly delabeled or are erroneous relabeled. This highlights an opportunity for future study and opportunities for process improvement initiatives to optimize benefit from antibiotic stewardship initiatives.