Health economic analysis of allergen immunotherapy for the management of allergic rhinitis, asthma, food allergy and venom allergy: A systematic overview.

BACKGROUND: The European Academy of Allergy and Clinical Immunology (EAACI) is developing guidelines for allergen immunotherapy (AIT) for the management of allergic rhinitis, allergic asthma, IgE-mediated food allergy and venom allergy. To inform the development of clinical recommendations, we undertook systematic reviews to critically assess evidence on the effectiveness, safety and cost-effectiveness of AIT for these conditions. This study focusses on synthesizing data and gaps in the evidence on the cost-effectiveness of AIT for these conditions. METHODS: We produced summaries of evidence in each domain, and then, synthesized findings on health economic data identified from four recent systematic reviews on allergic rhinitis, asthma, food allergy and venom allergy, respectively. The quality of these studies was independently assessed using the Critical Appraisal Skills Programme tool for health economic evaluations. RESULTS: Twenty-three studies satisfied our inclusion criteria. Of these, 19 studies investigated the cost-effectiveness of AIT in allergic rhinitis, of which seven were based on data from randomized controlled trials with economic evaluations conducted from a health system perspective. This body of evidence suggested that sublingual immunotherapy (SLIT) and subcutaneous immunotherapy (SCIT) would be considered cost-effective using the (English) National Institute for Health and Clinical Excellence (NICE) cost-effectiveness threshold of £20 000/quality-adjusted life year (QALY). However, the quality of the studies and the general lack of attention to characterizing uncertainty and handling missing data should be taken into account when interpreting these results. For asthma, there were three eligible studies, all of which had significant methodological limitations; these suggested that SLIT, when used in patients with both asthma and allergic rhinitis, may be cost-effective with an incremental cost-effectiveness ratio (ICER) of £10 726 per QALY. We found one economic modelling study for venom allergy which, despite being based largely on expert opinion and plausible assumptions, suggested that AIT for bee and wasp venom allergy is only likely to be cost-effective for very high-risk groups who may be exposed to multiple exposures to venom/year (eg bee keepers). We found no eligible studies investigating the cost-effectiveness of AIT for food allergy. CONCLUSIONS: Overall, the evidence to support the cost-effectiveness of AIT is limited and of low methodological quality, but suggests that AIT may be cost-effective for people with allergic rhinitis with or without asthma and in high-risk subgroups for venom allergy. We were unable to draw any conclusions on the cost-effectiveness of AIT for food allergy.

Three days rush venom immunotherapy in bee allergy: safe, inexpensive and instantaneously effective.

BACKGROUND: Rush venom immunotherapy (VIT) is highly effective in vespid venom allergy, but comparable data regarding bee venom (BV) allergy are sparse. We evaluated its safety, efficacy and cost in BV-allergic patients. METHODS: Conventional or rush VIT were offered to all patients with systemic reaction to insect sting. Rush VIT was also given to hyperreactive patients who failed to reach the maintenance dose with conventional VIT due to multiple systemic reactions. In BV-allergic patients, honeybee sting challenge was performed within 1 week after reaching the maintenance dose. RESULTS: 179 patients, some of them allergic to more than one venom, received 246 rush VIT courses. Bee VIT was administered to 132 patients (73.7%); 173 patients (96.6%) reached the maintenance dose. The incidence of systemic reactions was 29.6%. They were more common in VIT with BV than with vespid venoms (31.1 and 16.3%, respectively, p = 0.01). After excluding the hyperreactive subgroup (n = 20), this difference was not significant (23.7 and 16%, respectively, p = 0.19). Despite the high incidence of systemic reactions (15 of 20, 75%) among hyperreactive patients, 17 patients (85%) achieved the maintenance dose. Sting challenges resulted in systemic reaction in 4 of 8 (50%) hyperreactive patients and in 2 of 47 (4.3%) ordinary patients. The cost of rush VIT was 41% of that of conventional VIT. CONCLUSIONS: Rush VIT with BV is safe, instantaneously effective, less expensive and enables most patients with previous failures of conventional VIT to reach the maintenance dose.