Antimicrobial stewardship paired with allergy testing increases appropriate therapies

A program in Australia that integrated antibiotic allergy testing with antimicrobial stewardship significantly improved antibiotic use and appropriateness, and was also effective in de-labeling patients who had previously been labeled as having antibiotic allergies, study data showed.

“Over the past 2 decades, the prevalence of patient-reported antibiotic allergy in hospitalized patients has increased and is now estimated to be 18% to 25%,” Jason A. Trubiano, MBBS, FRACP, of the department of infectious diseases at Austin Health, Melbourne, and colleagues wrote. “This type of overlabeling, which may persist over a lifetime, has been associated with poorer clinical outcomes and increased health care resource utilization.”

To combat overlabeling, Trubiano and colleagues wrote, professionals have considered incorporating antibiotic allergy testing into antimicrobial stewardship programs.

“However, the impact of coordinated multidisciplinary [antibiotic allergy testing] programs on [antimicrobial stewardship] has not been well studied,” they wrote.

The researchers evaluated an antibiotic allergy testing and antimicrobial stewardship program that was implemented in two large hospitals for 14 months, beginning in May 2015. Both centers generated referrals for testing with the help of a wide array of specialists. Patients were referred if they fell into one of three categories: a ’non-immune mediated side effect,’ an antibiotic allergy that had been disproved by tolerance of an inadvertent drug administration, or a history “consistent with immediate hypersensitivity.”

Trubiano and colleagues recorded each patient’s antibiotic use for the year before testing and for 3 months after testing, as well as antibiotic allergy history, demographics, age-adjusted Charlson comorbidity index and infection history. The study outcomes were the proportion of patients who were de-labeled from having an antibiotic allergy, antibiotic appropriateness and the spectrum of antibiotic courses prescribed before and after antibiotic allergy tests.

A total of 118 patients were tested for antibiotic allergies, with patients reporting 226 antibiotic allergy labels, the researchers reported. More than half (53%) of reported allergies involved at least one penicillin-class medication. The program resulted in de-labeling of 98 patients (83%), Trubiano and colleagues wrote, with 56% (n = 55) having all labels removed.

After researchers adjusted for care setting, Charlson comorbidity index and indication, doctors were more likely to prescribe narrow-spectrum penicillin drugs after antibiotic allergy testing (adjusted OR = 2.81; 95% CI, 1.45-5.42), as well as narrow-spectrum beta-lactams (OR = 3.54; 95% CI, 1.98-6.33) and appropriate antibiotics (OR = 12.27; 95% CI, 5-30.09), the researchers wrote. Furthermore, patients were less likely to be prescribed restricted antibiotics (OR = 0.16; 95% CI, 0.09-0.29).

“We demonstrated the success of a real-world integrated program to show significant improvement in antibiotic appropriateness in a patient cohort frequently in need of antibiotic therapy, of which a large portion were immunocompromised with serious ADR history,” the researchers wrote. “Future work must focus on improving [antibiotic allergy label] assessment at the onset, enhanced clinician and pharmacist education to sustain improvements in antibiotic utilization and evaluation of the long-term impact and cost-benefit of [antibiotic allergy testing].” – by Andy Polhamus

Disclosure: The researchers report no relevant financial disclosure.