Allergy Evaluation Found to Be Cost-Effective in Unverified Penicillin-Allergic Patients

That treating patients based on an unverified allergy to penicillin has—perhaps expected, but yet unintended—consequences both in terms of outcomes and overall cost-of-care is well known.

What isn’t as well known is the exact scope of these issues.

Using time-driven activity-based costing (TDABC), a team of Massachusetts General Hospital (MGH)-based researchers sought to provide important insight into these questions, at a time when the medical field has been debating the practicality of performing a penicillin allergy evaluation in patients prior to initiating treatment. The results of the TDABC assessment were published in the September 22, 2017, issue of the Journal of Allergy and Clinical Immunology: In Practice (JACIIP).

The lead author of the JACIIP paper, Kimberly G. Blumenthal, MD, MSc, Division of Rheumatology, Allergy and Immunology, Department of Medicine and Edward P. Lawrence Center for Quality and Safety, MGH, participated in a pro-con debate regarding implementation of penicillin allergy evaluation during the annual meeting of the American Academy of Allergy, Asthma, and Immunology in March 2017. A summary of the discussion was also published in the September 22, 2017, issue of JACIIP, and covered by Contagion^® earlier this month.

For the TDABC evaluation, Dr. Blumenthal and colleagues estimated the cost of penicillin allergy evaluation “throughout the care pathway” in 30 outpatients. The authors used a “base-case evaluation” that included penicillin skin testing and a 1-step amoxicillin drug challenge, which was performed by an allergist.

In the 30 outpatients, they found that the base-case penicillin allergy evaluation cost $220 (in 2016 US dollars). This figure included $98 for personnel, $119 for consumables, and $3 for space. In subsequent sensitivity analyses, the authors found that they were able to reduce costs by using only the drug challenge component of the evaluation. In this approach, performed under the supervision of nurse practitioners, total costs were $170.

“[Our] work supports that allergy evaluation is an inexpensive intervention and that given the downstream benefits may well be cost-effective,” said study co-author Rochelle Walensky, MD, MPH, Professor of Medicine at Harvard Medical School and a practicing Infectious Disease physician at MGH. “Certainly, cost [is] a major consideration [in the decision as to whether to perform an evaluation]; however, it is not the only one. There is a large population of people with a documented, though unverified, penicillin allergy and the demand for testing may easily overwhelm the ‘supply’ of allergists and/or immunologists to conduct such testing, especially in more rural communities without less access to subspecialty care. We advocate that it may serve the community well to expand the workforce available to conduct such testing.”

Indeed, with this in mind, the authors of the JACIIP paper performed additional assessments varying “provider type, clinical setting, procedure type, and personnel timing,” all of which led to “modest changes,” they note in TDABC estimates (range $214 to $246). However, they found that higher costs were associated with performing allergy evaluation in a “low-demand practice setting” ($268) and after including “clinician documentation time” ($288). Overall, the lowest TDABC estimate for penicillin allergy evaluation in their analysis was $40 and the highest was $537.

Dr. Walensky told Contagion^®: “Given the relatively low cost and anticipated substantial clinical and economic benefit, we would advocate for routine allergy evaluation among those who are reported to have an unverified penicillin allergy and that such expenses should be covered by insurance.”

Brian P. Dunleavy is a medical writer and editor based in New York. His work has appeared in numerous healthcare-related publications. He is the former editor of Infectious Disease Special Edition.