A Comprehensive Prospective Study of Costs Associated to the Evaluation of beta-lactam Allergy

BACKGROUND AND OBJECTIVE: Being labelled as allergic to penicillin or unverified beta-lactam allergy result in patients receiving broader-spectrum antibiotics that may be more toxic, less effective, and/or with a higher cost. Objective: We aimed to evaluate real costs of beta-lactam allergy evaluation. METHODS: A prospective real life observational study designed to evaluate all adult patients that consulted during one year for suspected beta-lactam allergy. Direct and indirect costs were systematically recorded. Direct health costs were calculated by taking into account the number of visits and all complementary and diagnostic tests performed; direct non-health costs by considering the number of visits and the kilometers from their homes to the Allergy Service; and indirect costs by considering the absenteeism. RESULTS: A total of 296 patients with suspected allergy to beta-lactams were evaluated in our outpatient clinic from June 1st, 2017 to May 31th, 2018. Total direct health care costs were €28,176.70, with a mean cost and a standard deviation (SD) of €95.19 (37.20). Direct non-health costs reached €6,551.73, that is €22.13 (40.44) per patient. Indirect health costs reached €20,769.20, with a mean of €70.17 (127.40). In summary, the total cost was €55,497.63, which means a cost per patient of €187.49 (148.14). CONCLUSIONS: Even considering all possible costs, the evaluation of beta-lactam allergy is not expensive and can save future expenses due to unnecessary use of more expensive and less effective antibiotics.