Penicillin skin testing in methicillin-sensitive staphylococcus aureus bacteremia: A cost-effectiveness analysis

Area of Science:

• Infectious Diseases
• Health Economics
• Clinical Allergy

Background:

• Beta-lactam antibiotics are preferred for methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia.
• A significant percentage of inpatients report penicillin allergy, leading to suboptimal treatment with alternatives like vancomycin.
• Accurate identification of true penicillin allergy is crucial for effective MSSA bacteremia management.

Purpose of the Study:

• To evaluate the cost-effectiveness of inpatient penicillin skin testing (PST) for adult patients with self-reported penicillin allergy undergoing treatment for MSSA bacteremia.
• To compare the economic impact of implementing PST versus no allergy confirmation in this patient population.

Main Methods:

• A decision analytic model was employed to compare PST intervention with no confirmatory testing.
• The primary outcome measured was the incremental cost-effectiveness ratio (ICER) over a one-year period.
• Quality-adjusted life years (QALYs) were used to assess effectiveness, with sensitivity analyses performed to address uncertainty.

Main Results:

• Implementing PST for all MSSA bacteremia patients with reported penicillin allergy resulted in lower costs ($12,559/patient) and higher QALYs (0.73/patient) compared to no testing ($13,219/patient, 0.66 QALYs/patient).
• The cost-effectiveness estimate was -$9,429 per QALY gained, indicating cost savings.
• The break-even point for PST implementation was determined to be $959.98, below which PST is cost-saving.

Conclusions:

• Inpatient penicillin skin testing services are a cost-effective strategy for confirming penicillin allergy in patients with MSSA bacteremia.
• This approach helps avoid suboptimal therapies and improves patient outcomes.
• Economic analysis supports the routine use of PST in this clinical setting.