Evaluating the cost-effectiveness of testing pregnant women for penicillin allergy

Abstract

Introduction True penicillin allergy is rare and is commonly incorrectly reported. In fact, less than five percent of patients who report a penicillin allergy will have a currently active clinically-significant IgE- or T-cell-mediated hypersensitivity when appropriately tested. Penicillin is the agent of choice for intrapartum antibiotic prophylaxis to reduce the risk of group B streptococcus early-onset disease in the newborn. Inaccurate penicillin allergy status may lead to inappropriate antibiotic use, as most alternative drugs are more expensive and broader spectrum than penicillin. Penicillin allergy testing has been found to be safe in pregnancy and cost-effective in other patient populations. Objective To evaluate the cost-effectiveness of penicillin allergy testing and appropriate antibiotic treatment (test then treat strategy) compared to usual care among pregnant women. Methods We developed a decision tree to evaluate the cost of providing appropriate care via a test then treat strategy for pregnant women who report a penicillin allergy, compared to usual care. Results Using the test then treat strategy the additional cost to ensure appropriate care for all pregnant women who report a penicillin allergy, was $1122.38 per person. Adopting a test then treat strategy increased the number of appropriate antibiotic use from 7,843/10,000 to 10,000/10,000 simulations. Conclusion Our results show that a test then treat strategy for pregnant women who report a penicillin allergy is a good-value intervention.

The Cost of Developing and Implementing an Antepartum Referral Program for Penicillin Allergy Evaluation at a Single Academic Tertiary Care Hospital

“…32 Furthermore, cost of allergy evaluation in our study of real-world data was less than estimates from a recent pregnancy specific decision tree model, which found a per person cost of $1,122 (in 2020 U.S. dollars). 27 Our sensitivity analysis showed a slight increase in median cost through a single-visit protocol ($413; IQR: $299–611) and a single visit with direct oral challenge protocol ($413; IQR: $299–582); however, this was only because not all referred patients underwent allergy evaluation. When considering only patients who followed through with their evaluation, the median cost decreased by $40 with a single-visit protocol and by $73 with a single-visit protocol using direct oral challenge.…”

“…Our program did find that alternative antibiotics were more likely to be used in the nonreferred group and these alternative antibiotics (i.e., clindamycin or vancomycin) are known to be more expensive than first-line βlactam antibiotics (i.e., penicillin or cephalexin). 4,27 We suspect that we would have detected a difference related to antibiotic cost in a larger cohort. Furthermore, while not statistically significant, secondary outcomes including postpartum infection, neonatal intensive care unit admission, neonatal laboratory draw, neonatal antibiotic treatment, and neonatal length of hospital stay all appeared to favor patient allergy referral.…”

“…penicillin or cephalexin). 4,27 We suspect that we would have detected a difference related to antibiotic cost in a larger cohort. Furthermore, while not statistically significant, secondary outcomes including postpartum infection, neonatal intensive care unit admission, neonatal laboratory draw, neonatal antibiotic treatment, and neonatal length of hospital stay all appeared to favor patient allergy referral 4 .…”

“…We hypothesized that while there would undoubtedly be a cost associated with program development and allergy verification, these costs would be modest. Additionally, given trends towards increased morbidity in the non-referred patient group and known increased cost of alternative antibiotics 27 , we hypothesized there may even be short term cost benefit in childbirth hospitalization among patients who were referred for allergy evaluation.…”