Is there a higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococcus (VRE) colonization in patients with antibiotic allergy labels?

Risk of Multidrug Resistant Bacteria Acquisition in Patients with Declared β-Lactam Allergy during Hospitalization in Intensive Care Unit: A Retrospective Cohort Study (2007-2018)

Introduction

The risk of extended spectrum β-lactamase (ESBL) bacterial acquisition in patients with β-lactam allergy has been poorly investigated. In a previous study conducted over a 6-year long period (2007-2012), we found that patients with declared β-lactam allergy had a higher risk of ESBL bacterial carriage at admission in intensive care unit (ICU), but they had not a higher risk of ESBL bacterial acquisition. We present the final results of the study which was eventually conducted over a 12-year long period (2007-2018).

Materials and Methods

The study included all patients admitted in ICU and receiving antibiotic treatment from January 2007 to December 2018. ESBL bacterial acquisition was the main clinical outcome. Mortality in ICU, multidrug resistant bacterial carriage at admission and discharge were the secondary outcomes.

Results

Overall, 3332 patients were included, 132/3332 (3.9%) were labelled β-lactam allergic, while 3200/3332 (96.1%) did not presented β-lactam allergy. No significant difference in rates of ESBL acquisition was detected (4/132, 3% vs. 78/3200, 2.4%; p = 0.17). Patients with β-lactam allergy had higher rates of ESBL bacterial carriage at admission (19/132, 14.4% vs. 248/3200, 7.8%, p = 0.01) and at discharge (22/132, 16.7% vs. 351/3200, 11%, p = 0.04) than nonallergic patients. No differences in mortality, duration of hospitalization, and carriage of methicillin resistant Staphylococcus aureus were reported. Female gender was the only factor associated with β-lactam allergy at the multivariate analysis.

Conclusions

This study confirms that patients with declared β-lactam allergy had not a higher risk of ESBL bacterial acquisition during hospitalization in ICU. However, they had a higher ESBL bacterial carriage at admission.

Prevalence of Antibiotic Allergy Labels in a Tertiary Referral Center in Belgium

BACKGROUND

Antibiotic (AB) allergies are among the most frequently occurring adverse drug reactions. In US literature, AB allergy labels (AAL) are reported in 10% to 15% of patients' charts; however, large-scale European analyses are scarce.

OBJECTIVES

To retrospectively assess the prevalence of AAL in a tertiary referral hospital in Belgium between 2010 and 2018.

METHODS

Patients who consulted and/or were hospitalized during the study period, who had been labeled with an AB allergy, were selected for further analysis.

RESULTS

Of 1,009,598 unique patients (outpatients, n = 736,469; inpatients, n = 273,129), 28,147 patients (3%) were registered with 1 or more AAL, being 1% of outpatients (n = 9562) and 7% of inpatients (n = 18,585). Women were more likely to carry an AAL (68%) compared with men (32%, P < .001). In patients with an AAL, 9% had multiple labels and 5% had labels for multiple AB classes. Most frequently, beta-lactams were involved (84% of AAL), followed by quinolones (7%) and sulfonamides and macrolides (both 3%). Moreover, 88% of the reactions were self-reported, mostly being an unspecified rash (53%), whereas only 3% were considered confirmed AAL.

CONCLUSION

With an overall prevalence of 3%, the burden of AAL is less in our Western European center compared with US reports. However, this prevalence most likely still represents an overestimation of genuine AB allergic patients because most labels lack confirmation and/or specifications. Our work indicates that knowledge of the local epidemiology of AAL is necessary to estimate the impact of better allergy labeling and delabeling strategies.

The impact of antibiotic allergy labels on antibiotic exposure, clinical outcomes, and healthcare costs: A systematic review

OBJECTIVE

A growing body of evidence suggests that antibiotic allergy labels as documented in medical records are a risk factor for poor clinical outcomes. In this systematic review, we aimed to determine how antibiotic allergy labels influence 3 domains: antibiotic use and exposure, clinical outcomes, and healthcare-related costs.

DESIGN

We performed a systematic review to identify studies reporting outcomes in patients with antibiotic allergy labels compared to nonallergic counterparts. The search included PubMed, EMBASE, Cochrane CENTRAL, EBSCO, Cochrane Database of Abstracts of Reviews of Effects and Web of Science. Two reviewers independently screened studies for inclusion and abstracted data. Studies were graded using the Newcastle-Ottawa quality assessment scale. Study outcomes included antibiotic use, clinical outcomes, and economic outcomes.

RESULTS

In total, 41 studies met our criteria for inclusion. These studies varied in medical specialty, patient population, healthcare delivery system, and design, but most were conducted among adults age >18 years (85%) in the inpatient setting (82.5%). Among 34 studies examining antibiotic exposure, 32 (94%) found that patients with antibiotic allergy labels received more broad-spectrum antibiotics. Moreover, 31 studies examined clinical outcomes such as length of hospitalization, ICU admission, hospital readmission, multidrug-resistant or opportunistic infection, or mortality, and 27 (87%) found that allergy-labeled patients had at least 1 negative outcome. Of 9 studies examining healthcare costs, 7 (78%) found that allergy-labeled patients incurred significantly higher drug or hospital-related costs.

CONCLUSIONS

Antibiotic allergy labels have negative effects on antibiotic use, clinical outcomes, and economic outcomes in a variety of clinical settings and populations.