Allergy immunotherapy in reducing healthcare cost

To evaluate the cost-effectiveness of allergen immunotherapy (AIT) in the treatment of allergic rhinitis and asthma. Individual studies and systematic reviews that included information on AIT economic outcomes as compared with symptomatic drug treatment (SDT) were evaluated.

One systematic review that included 14 studies concluded that subcutaneous and sublingual immunotherapy may be cost-effective compared with SDT from around 6 years. Another systematic review of 24 studies comparing economic outcomes of subcutaneous allergy immunotherapy and/or sublingual allergy immunotherapy with SDT found compelling evidence for cost-savings with both forms of AIT over SDT. There was no strong evidence indicating superior cost-efficacy of subcutaneous allergy immunotherapy or sublingual allergy immunotherapy over SDT in either of these systematic reviews. Individual studies have demonstrated AIT cost-savings as high as 80% compared with SDT. Significant cost-savings were reported as early as 3 months after AIT initiation. In some studies, cost-efficacy time-point was not established until after treatment discontinuation - presumably due to time required for the clinical benefits to outweigh the AIT treatment costs. Although some economic modeling studies included the costs of 'asthma prevented', the collective literature of AIT economics provides very little to no information about the cost benefits of the preventive aspect of AIT.

Overall, individual studies and systematic reviews provide strong evidence for the cost-effectiveness of AIT over SDT. The magnitude of cost-efficacy is likely underestimated in that few studies consider the cost-savings due to AIT's long-term benefits or preventive effect.