(480) Cost-effectiveness of 2022 American Academy of Allergy, Asthma & Immunology Practice Parameter for cesarean prophylaxis

The updated 2022 American Academy of Allergy, Asthma and Immunology (AAAAI) Practice Parameter suggests de-emphasis of skin allergy testing compared to drug challenge for majority of patients with penicillin allergy. We sought to evaluate cost-effectiveness of incorporating 2022 AAAAI practice parameter for cefazolin (Ancef) cesarean prophylaxis (AP) versus referral for penicillin allergy testing (PAT).

Study Design:

A decision analytic model was constructed to compare the costs and outcomes of 2 strategies for cesarean prophylaxis with penicillin allergy:
AAAAI 2022 guidelines for AP (excluding history of severe cutaneous reaction).
Current practice of referral for PAT prior to surgery.
Data was sourced from published literature, drug pricing databases, and expert opinion. Costs included allergy testing, antibiotics, and complications. Effects included testing compliance, Ancef reactions and de-labeling penicillin allergy. Comparing the costs and effects of each strategy determined the incremental cost-effectiveness ratio of cost per wound infection averted.  Sensitivity analysis tested the robustness of the results to variability in the data and model structure.

Results:

In the base-case, incorporation of the AAAAI practice parameter was the choice strategy, with the mean cost of $283 compared to $588.  Referral for penicillin allergy testing costs $43,916 per case of wound infection avoided.  However, when incorporating the estimated lifelong cost of penicillin allergy into the decision model, referral for penicillin allergy testing becomes the dominant, cost saving strategy, with mean cost of $1,367 compared to $4,755. When considering the lifelong cost of penicillin allergy, incorporation of AAAAI practice parameter costs $487,934 per wound infection avoided.

Conclusion:

Incorporation of AAAAI practice parameter for cesarean prophylaxis is cost saving compared to referral for penicillin allergy testing. However, when considering the lifelong cost of penicillin allergy and potential to de-label penicillin allergies during pregnancy, referral for allergy testing becomes the cost-saving strategy.