Reports.qxp

Update on Laboratory Testing to Identify
Individuals With Inhalant Allergies
Anna Wetherbee
(President, HW Consulting)
Originally published in LABMEDICINE (Lab Med. 2007;38;649–650).
The quality and cost of health care in the United States is and enzymeimmunoassay (EIA) tests that use color development, increasingly a focus of media and political debate. Breakthroughs fluorescence, or chemiluminescence for detection of allergen- in medical technology and the discovery of new treatment op- specific IgE antibody, advances in technology have increased the tions for a variety of diseases, alongside serious concerns about reliability and diagnostic sensitivity of these tests in identifying increasing health care costs and the rising number of uninsured individuals with IgE-mediated disease. These advances have Americans, make frequent headlines. In the midst of discoveries caused many experts to conclude that blood tests are as useful as and debates that are shaping the future of American health care, skin testing for helping clinicians determine the presence or an unlikely topic has been getting a surprising amount of atten- absence of allergy and specific allergen sensitivities.8 tion: allergy testing. Although the newest diagnostic technologies In vitro diagnostic technology promises at least 1 significant related to the identification and treatment of individuals with benefit: PCPs now have an objective tool to differentiate inhalant allergies are more than a decade old and hardly break- between allergic and non-allergic disease and implement more ing news, allergy testing has been highlighted in recent articles effective treatment strategies in their patients. In 1999 and 2000, in both The New York Times1 and The Wall Street Journal,2 as the leading manufacturer of blood allergy testing, Phadia (for- well as in several industry publications.
merly Pharmacia Diagnostics), initiated a marketing campaign So why all the attention being given to allergy testing? to bring this tool to the primary care setting. Using the promo- The simple answer may be that while the technology related to tional slogan “Is It Allergy?” Phadia proposed that the use of a allergy testing is not new, the paradigm for using it is. Allergy panel of individual tests for common allergens could provide testing, once the exclusive domain of specialists, has been more value in the discrimination of individuals with inhalant allergy recently marketed to primary care physicians (PCPs), sparking disease from those without this disease. an intense debate over what constitutes clinically-appropriate An accurate differential diagnosis of allergic versus non- allergic disease has significant potential benefits. It can direct Consider this: more than 50% of Americans identify them- physicians to more appropriate care, improving patient selves as seasonal allergy sufferers.3 Clinical evidence suggests that outcomes and satisfaction. It may also decrease costs from re- among these individuals, more than half in fact do not have an peated office visits due to ineffective treatment. Diverting non- inhalant allergy.4-6 Moreover, the majority of these individuals are allergic patients from high-cost allergy drugs to more treated by PCPs and rarely see an allergy specialist, which means cost-effective and clinically-appropriate options can save signifi- few of them ever receive objective diagnostic testing to confirm cant pharmacy costs for insurers. Finally, it may improve referral whether their symptoms are truly caused by an inhalant allergen patterns, providing a simple solution for primary care while bet- or not. The result is a large number of patients being presump- ter identifying patients for specialist referral who may need more tively diagnosed and treated for allergies, many of whom do not extensive allergy testing and treatment. in fact have an allergy-mediated disease.7 This can be costly for Allergy testing in the primary care setting soon became big patients, physicians, and insurance companies who share the business. Two years into Phadia’s primary care marketing cam- burden of ineffective treatment and inadequate outcomes.
paign, Quest Diagnostics partnered with Phadia to promote Manufacturers of blood tests for specific allergens aim to their message through its sizeable direct-to-physician sales force.
change that. Traditionally, allergy testing has been performed According to Surya Mohapatra, President of Quest Diagnostics, by a trained specialist using skin-prick testing with specific allergens.
in April 2006, “…allergy testing has grown steadily and signifi- Blood tests, or allergen-specific IgE antibody in vitro diagnostic cantly. Our efforts have focused on educating primary care tests, which quantitatively measure the presence or absence of physicians and pediatricians about the benefits of allergy blood allergen-related IgE antibodies in serum prepared from an indi- testing. Instead of referring patients to specialists, the primary vidual’s blood sample, can be ordered by PCPs or specialists. care physicians now are able to test their patients and prescribe In vitro diagnostic tests for allergen-related antibodies have improved significantly since their creation in the early 1970s. From Despite the clinical appeal of a simple, objective laboratory the first radioallergosorbent test (RAST) to the more sensitive mod- test to enable better identification of individuals with allergic ified RAST, to the current automated radioimmunoassay (RIA) disease in the primary care setting, PCPs have been slow to November 2007 ᭿ Volume 38 Number 11 ᭿ LABMEDICINE 649
embrace in vitro allergy testing in the routine management of be positive. However, the added value of specific allergen infor- their patients. This hesitance may be due in part to a question- mation in guiding treatment in primary care is controversial.
able total value proposition. Currently, the most common in Using the MIA test as a first-line strategy in the evaluation of vitro allergy testing approach uses a panel of 15 or more com- patients with suspected allergic disease may limit more exten- mon specific allergens to identify individuals with allergic dis- sive testing, and its attending cost, to only those patients with ease and the most likely allergen triggers causing their disease.
bona fide IgE-mediated hypersensitivity disease. Billing for these panels is computed on a per allergen basis and There is an urgent need in health care today to improve may cost as much as $185 (based on the current Medicare fee patient outcomes while managing costs. The laboratory testing schedule), offsetting potential savings. A recent pilot study at options and strategies for achieving these goals in the manage- Wilford Hall Medical Center, San Antonio, TX, found that ment of allergic disease in primary care have been reviewed the direct cost of testing symptomatic patients with a panel of briefly above. Laboratory professionals can play a key role in specific allergens outweighed the direct estimated savings from educating physicians about available laboratory test options and eliminating inappropriate prescriptions.10 Additionally, while promoting implementation of clinically-effective and cost-effi- accurately discriminating between allergic and non-allergic cient laboratory testing strategies in the management of allergy patients provides clear clinical value, some experts question and other diseases. LM
the value of identifying specific inhalant allergen sensitivities, Disclaimer: HW Consulting has no conflicts of interest or
especially pollens, in primary care patients, given the expense disclosures. HW Consulting provides consulting services in the and practical limitations of avoiding allergen exposure as a areas of reimbursement, health care economics, and disease man- symptom management strategy. According to Dr. Henry agement, and has had prior consulting relationships with 2 of Homburger, Professor of Laboratory Medicine at the Mayo the leading allergy diagnostic manufacturers. For more informa- Clinic, “the most common misuse of tests for individual IgE tion regarding HW Consulting, see www.hw-consult.net.
antibodies occurs when tests are ordered in large numbers to‘look for allergy’ or screen in a patient who does not have clini- 1. Tarkan L. In testing for allergies, a single shot may suffice. The New York cal signs and symptoms or a medical history that strongly sug- gests immediate hypersensitivity disease.”11 2. Fuhrmans V. Doctors assail UnitedHealth’s threat of fines. The Wall Street A multiple inhalant allergen (MIA) test, otherwise known as a “multiallergen test” (CPT 86005), usually consisting of a 3. ICR. Survey reveals allergies show no boundaries, no matter where you live.
combination of 6 to 12 allergens in a single test, may be a more Available at: http://www.icrsurvey.com/Study.aspx?f=zyrtec.html. cost-effective and clinically-useful alternative to a panel of spe- 4. Szeinbach SC, Williams PB. Identification of allergic disease among users of cific allergen tests in identifying individuals with inhalant al- antihistamines. JMCP. 2004;10:3.
lergy disease in primary care. The MIA test has a diagnostic 5. Altman CL, Becker JW, Williams PV. Allergy in Primary Care. Philadelphia: efficiency that compares well with that of skin testing and anegative predictive value for allergic rhinitis of >95%.12 In fact, 6. Dykewicz MS, Fineman S, Skoner DP, et al. Diagnosis and management of rhinitis: Complete guidelines of the Joint Task Force on Practice Parameters the multiallergen test has the highest negative predictive value in Allergy, Asthma, and Immunology. Ann Allergy Asthma Immunol. 1998;81: for atopic dissease of any laboratory test currently available.13 Moreover, Poon and colleagues14 commented, “qualitative mul- 7. Szeinbach S, Brock W, Muntendam P, et al. Identification of allergic disease tiallergen screening tests have been found to be clinically effec- among users of antihistamine. J Manag Care Pharm. 2004;10:234–238.
tive, having excellent sensitivity, specificity, and efficiency,” and, 8. US Department of Health and Human Services, National Institutes of Health.
Expert panel report 3: Guidelines for the diagnosis and management of “the AAOA [American Academy of Otolaryngic Allergy] deter- asthma. NIH Publication No. 07-4051:167. Bethesda, MD: NIH; 2007.
mined that it is possible to decrease the number of tests without 9. Quest Diagnostics, Quarter ended March 31, 2006. Conference call prepared compromising clinical practice by: 1) using screen to remove non-allergic patients from further unnecessary testing; and 2) 10. Welsh N, Hart J, Hoeben B, et al. The pharmacoeconomic impact of eliminating cross-reactive or unusual allergens from a typical ImmunoCAP testing on the usage of second-generation antihistamines and a allergen panel unless indicated by clinical history.” In addition, leukotriene receptor antagonist at Wilford Hall Medical Center. J Am PharmAssoc. 2006;46:627. HA Sampson, a prominent pediatric allergist, has stated, “as 11. Homburger HA. Mayo Reference Services “Communique.” September, 2004.
suggested by us many years ago, and as convincingly shownmore recently by Fiocchi et al, qualitative multiallergen tests 12. Linneberg A, Husemoen LLN, Nielsen NH. Screening for allergic respiratory disease in the general population with the ADVIA Centaur allergy screen assay.
provide an excellent means for primary care physicians to iden- tify atopic children, enabling them to provide more appropriate 13. Leung DM, Sampson HA, Geha RS, et al. Pediatric Allergy, Principles and care for patients with mild disease or to refer those with more Practices. Philadelphia: Mosby; 2003: 238. severe disease for further allergy evaluation.”15 14. Poon AW, Goodman CS, Rubin RJ. In vitro and skin testing for allergy: Unlike testing for specific allergens, the MIA test, if posi- Comparable clinical utility and costs. Am J Manag Care. 1998;4:969–985.
tive, will not identify the specific allergen causing this test to 15. Sampson HA. Guest Editorial: “Can we diagnose atopy with a laboratory test?” Ann Allergy Asthma Immunol. 2004:93;307–308.
LABMEDICINE ᭿ Volume 38 Number 11 ᭿ November 2007

Source: http://www.hwconsulting.net/ImprovingAllergyDiagnosticEfficiencyinHealthCare.pdf