The Cost of Self-Reported Penicillin Allergy: A Systematic Review

Patients who report a penicillin (PCN) allergy receive suboptimal antibiotic therapy compared with patients not reporting an allergy. However, a majority of patients who report PCN allergy are not truly allergic on confirmatory testing. Ruling out PCN allergy by testing may improve clinical and economic outcomes for patients with reported allergies requiring antibiotic therapy.

The objective of this study was to summarize clinical and economic outcomes associated with PCN allergy and provide recommendations for future cost-effectiveness analyses for PCN allergy testing.

A literature search was conducted using SCOPUS, EMBASE, and PubMed, including all articles published any date through April 25, 2017 (PROSPERO Registration number 42017064112). A total of 1518 abstracts were found during the initial search with 96 duplicates, for a total of 1422 articles for screening. Thirty articles were included for qualitative synthesis and full data extraction.

The majority of the studies included had an observational design focusing on inpatient admissions. The most frequently measured outcome in the context of PCN allergy was optimizing antibiotic therapy. Patients with PCN allergy were found to have direct drug costs during inpatient admission ranging from no difference to an additional $609/patient compared with patients without PCN allergy. Outpatient prescription costs were estimated from $14 to $193/patient higher for PCN allergic patients. Total inpatient costs were less for patients without PCN allergy with average savings from $1145 to $4254/patient.

Evaluations of clinical and economic outcomes of PCN allergy are primarily observational and focus on inpatient populations. Long-term relationships between PCN allergy and clinical and economic outcomes are unknown.