PURPOSE OF THE STUDY.
To characterize and quantify the use of food-specific serum IgE (sIgE) panels by PCPs and allergists.
Clinicians (physicians, nurse practitioners, and physician assistants) who placed orders for food sIgEs at the outpatient laboratory at Nationwide Children’s Hospital in Columbus, Ohio, were classified according to their primary area of clinical expertise, including allergy and immunology, PCP (including pediatricians, family medicine, and internal medicine), and gastroenterology.
This was a retrospective review of all food sIgE tests (individual tests and panels) ordered in 2013.
In the 1-year study time period, 10 794 single-food sIgE tests and 3065 allergen panels containing at least 1 food sIgE were ordered by 447 clinicians. Allergists ordered the majority of single-food sIgE tests compared with PCPs. PCPs ordered the majority of the allergen panels, and 45.1% of all sIgE tests ordered by PCPs were panels, compared with only 1.2% of orders placed by allergists. PCPs in practice for ≤15 years ordered ∼50% fewer sIgE panels, compared with PCPs in practice for ≥16 years. Allergists were much more likely to order single-food sIgE testing for one of the 8 most common food allergens (cow’s milk, egg, wheat, soy, peanut, tree nuts, fish, and shellfish, which account for >90% of all IgE-mediated food allergies) than were PCPs, who ordered significantly more sIgE tests for foods associated with a low prevalence of IgE-mediated food allergy, such as strawberry, beef, corn, and tomato. During the study period, the average laboratory charge for each individual sIgE was $26.92. The cost of each panel ranged from $134.60 (for the 5-allergen panel) to $619.16 (for the 23-allergen panel). The total cost of all sIgE tests ordered per patient was approximately twice as expensive for PCPs, with the majority of the discrepancy due to ordering sIgE panels.
Compared with allergists, PCPs order significantly more food allergen panels, more single-food sIgE tests for foods that infrequently cause allergy in children, and generate higher costs per patient for sIgE testing.
Accurate diagnosis of IgE-mediated food allergies is critical for management. The clinical history of an acute allergic reaction to a suspected trigger is the most important diagnostic tool. Percutaneous skin prick testing and sIgE assays confirm the suspected diagnosis. Oral food challenges are the gold standard in the diagnosis of a food allergy and can be conducted by a food allergy specialist if the diagnosis remains unclear. Clinical guidelines discourage indiscriminate use of sIgE panels, given the low positive predictive value of these tests when used arbitrarily. The Choosing Wisely campaign of the ABIM Foundation highlights this recommendation for allergy tests (http://www.choosingwisely.org/patient-resources/allergy-tests/). Food sIgE testing should not be performed without a history consistent with a potential IgE-mediated food allergy. Ordering a panel of tests for allergens does not reduce costs.
- Copyright © 2017 by the American Academy of Pediatrics