Immunotherapy OutcomesThe Health Economics of Allergen Immunotherapy
Section snippets
Methodologic approaches to economic analyses
Given the substantial economic burden associated with allergic disease, it is important to understand how different treatment strategies may mitigate allergy-related outcomes and costs of care (Table 1).16 Cost-effectiveness analysis (CEA) is a method used to evaluate the tradeoffs involved in choosing among interventions.16 Data regarding resource use may be captured from a variety of sources, including prospective clinical trials, patient or physician reports, or retrospective administrative
Economic analyses of allergic rhinitis treatments
Treatment of AR may include allergen avoidance, pharmacologic treatments, and SIT.17 Unfortunately, there have been no economic analyses of allergen avoidance measures and only 5 economic studies of pharmacologic treatments for AR to date.18, 19 The few existing economic analyses of pharmacotherapies for AR have been plagued by methodological flaws, such as small sample sizes, extrapolation of costs from short-term outcomes, limited information on the clinical benefits of comparators, and lack
Donahue
The earliest study was a retrospective analysis of administrative claims for 294,000 US health plan enrollees who filed a claim during the period 1988 to 1992.33 Investigators identified 603 adults and children with AR and/or asthma who had received at least 1 SIT injection and who had continuous membership during the year before and 2 years after their initial SIT administration. Costs related to SIT included all encounters with an SIT code, an allergen skin test, or a code for allergic
Le Pen
In a French study, investigators used physician survey data of patients receiving SIT to test the hypothesis that greater duration of SIT is directly related to the magnitude of decrease in the use of SDT.32 Among 1000 patients who had received SIT for a variety of allergies, 851 (85%) had completed surveys regarding aspects of their SIT treatment (duration and reasons for desensitization), and past 15-day allergy symptoms, other allergy treatments received, physician visits, allergy-related
Bernstein
A 1999 US study used data from a 1996 American College of Allergy, Asthma and Immunology report to compare the estimated the 5-year average cost of SIT plus SDT versus SDT alone among patients with AR.34 Data from 3 allergy treatment centers in different geographic regions in the United States provided the basis for estimating costs. Costs for SIT were based on the assumption that patients with AR would require daily use of an antihistamine/decongestant and intranasal corticosteroid spray. The
Schadlich
In 2000, a study used retrospective data from clinical trials, observational studies, and epidemiologic sources to model health outcomes associated with 3 years of SIT versus SDT in patients with AR over 10 years of follow-up.24 Direct costs included outpatient medical services, outpatient drug treatment, inpatient medical services, allergy-related diagnostic tests, treatment for adverse events, SIT allergen extract, and allergy medications. Resource use (physician visits, diagnostic tests) for
Berto
In another study, investigators analyzed the medical records of children receiving care for allergic disease at a single allergy center in Italy.21 Subjects who had 1 year of data before receiving sublingual immunotherapy (SLIT) and at least 3 years of data while on SLIT were selected. Of the 135 identified children, 34% had seasonal allergies and 66% had perennial allergy (house dust mites). About 61% had AR and asthma, 38% had asthma, and fewer than 1% had AR only. Outcome measures used to
Ariano
An economic analysis of SIT was performed using data from a prospective, single-site study in which 30 Italian adults with Parietaria pollen-induced rhinitis and asthma were randomly assigned to 3 years of SIT plus SDT (n = 20) or SDT alone (n = 10) and then followed for 3 years after completion of SIT.20 During the 4-month pollen season, patients recorded symptom scores, allergy drug use, and adverse drug reactions on a daily diary card; each month during the study, they recorded the number of
Bachert
A cost-utility analysis was conducted using data from a large, international (8 countries), randomized, double-blind, placebo-controlled trial in which 316 patients were randomized to a grass allergen tablet arm and 318 to a placebo (SDT) arm.25 During the clinical trial, patients received preseasonal SLIT for 16 to 35 weeks. To estimate the long-term effectiveness of SLIT, it was assumed that 3 years of treatment with the grass allergen tablet would result in sustained clinical benefits for
Hankin
A 7-year (1997–2004) retrospective analysis of Florida Medicaid claims data evaluated treatment outcomes and costs of children who were newly diagnosed with allergic rhinitis and naïve to SIT.29 Patients were selected who were newly diagnosed with AR, had at least 1 year of data preceding and 4 years of data following their first AR diagnosis, had received SIT following their first AR diagnosis, and had at least 6 months of data following termination of SIT. Among these 354 patients, medical
Hankin
A 10-year (1997–2007), retrospective claims, matched cohort study compared the median, 18-month, per-patient direct costs (pharmacy, outpatient visits, inpatient admissions) of Florida Medicaid-enrolled children (age <18 years) newly diagnosed with AR who subsequently received versus did not receive SIT.30 Those with AR who received at least 2 administrations of SIT were matched by age at AR diagnosis, sex, race/ethnicity, comorbid illness burden, and the presence of asthma, conjunctivitis, or
Hankin
In an 11-year (1997–2008), matched cohort, retrospective claims analysis of Florida Medicaid adult enrollees newly-diagnosed with AR, investigators reported even more compelling findings than those reported for children.31 At 18 months, total mean health care costs for inpatient ($10,352 vs $14,796, P = .003), outpatient excluding ($2466 vs $4181, P<.0001) or including ($2668 vs $4101, P<.0001) SIT, pharmacy ($5636 vs $6321, P<.0001) and total health care services ($10,626 vs $17,912, P<.0001)
Summary
We identified 15 studies from 1995 to 2011 that have examined the health economics of SIT. All focus on AR with or without asthma. Five studies specifically pertain to treatment of US patients29, 30, 31, 33, 34 and the remainder examine the economics of SIT among patients in Europe. Routes of SIT administration include subcutaneous injection,20, 23, 24, 27, 28, 29, 30, 31, 32, 33, 34 and sublingual immunotherapy.21, 22, 25, 26 There is wide variation in primary sources for health services use
References (47)
- et al.
The diagnosis and management of rhinitis: an updated practice parameter
J Allergy Clin Immunol
(2008) - et al.
Burden of allergic rhinitis: results from the Pediatric Allergies in America survey
J Allergy Clin Immunol
(2009) Quality of life in adults and children with allergic rhinitis
J Allergy Clin Immunol
(2001)- et al.
Allergen immunotherapy: a practice parameter third update
J Allergy Clin Immunol
(2011) - et al.
Health economics of asthma and rhinitis. II. Assessing the value of interventions
J Allergy Clin Immunol
(2001) - et al.
Economic evaluation of sublingual immunotherapy vs symptomatic treatment in adults with pollen-induced respiratory allergy: the Sublingual Immunotherapy Pollen Allergy Italy (SPAI) study
Ann Allergy Asthma Immunol
(2006) - et al.
Health-economic analyses of subcutaneous specific immunotherapy for grass pollen and mite allergy
Allergol Immunopathol (Madr)
(2005) - et al.
Allergy immunotherapy among Medicaid-enrolled children with allergic rhinitis: patterns of care, resource use, and costs
J Allergy Clin Immunol
(2008) - et al.
Allergen immunotherapy and health care cost benefits for children with allergic rhinitis: a large-scale, retrospective, matched cohort study
Ann Allergy Asthma Immunol
(2010) - et al.
L’impact de l’immunothérapie specifique sur le couts directs de la maladie allergique: une etude pragmatique
Rev Franc Allergol Immunol Clin
(1997)