METHODS: This was a retrospective chart review of 199 patients(233 CRD tests done),ages 0 to 17 years,who were seen by an allergist for a food allergy evaluation at a large academic outpatient medical center.Charts were reviewed for subjects with sP and CRD done at the same visit.An expense report for sP and CRD was obtained from the lab(CRD:$121.70, Food-sIgE:$24).The Fisher’s exact test was used to assess the relationship between peanut component testing and the sP cut-off level of 14kUA/L.
RESULTS: Of the 233 CRD tests reviewed, 116 were done in patients with sP<14kUA/L and 117 in patients with sP≥14kUA/L. Of the CRD tests in patients with sP≥14kUA/L, 4 had Arah1,2,3 and 9 <0.35kUA/L and of the CRD tests in patients with sP<14kUA/L, 38 had Arah1,2,3 and 9 <0.35kUA/L(3% versus 33%, p<0.0001),regardless of Arah8. Similar results were found if the cutoff of Arah1,2,3 and 9 was increased to 1 or 2kUA/L.Calculations of the costs revealed that approximately $14,239 was spent on CRD in patients with sP≥14kUA/L.
CONCLUSIONS: CRD in patients with sP≥14kUA/L provides little clinical benefit due to significantly higher likelihood of Arah1,2,3 and 9 >0.35kUA/L,with less opportunity to offer an oral challenge.Thus, indiscriminant CRD should be avoided to prevent unnecessary blood draws and increased health care costs.