Cost-effectiveness of grass pollen subcutaneous immunotherapy (SCIT) compared to sublingual immunotherapy (SLIT) and symptomatic treatment in Austria,Spain, and Switzerland

Background: While specific immunotherapy (SIT) has been proven to be cost-effective for the treatment of allergic rhinitis compared to symptomatic treatment, there is a lack of European studies in which sublingual (SLIT) and subcutaneous (SCIT) immunotherapy were compared. The present analysis is focused on the cost-effectiveness of SCIT compared to SLIT and symptomatic treatment of grass pollen allergy in Austria, Spain, and Switzerland. It will address specific properties of the underlying healthcare systems.

Methods: The investigation is based on a previously published health economic model calculation. This was designed as a Markov model with pre-defined health stages and a duration of 9 years covering specific preparations for SCIT (Allergovit) and SLIT (Oralair). The effectiveness was assessed as symptom-score based quality-adjusted life years (QALYs). Additionally, total cost has been determined as well as the cost-effectiveness of SCIT. The robustness of model results was proved in further sensitivity analyses.

Results: With regard to the effectiveness of both SCIT and SLIT, preparations were dominant compared to pharmacological symptomatic therapy. Both strategies were associated with additional cost, but, combined with the results on effectiveness, both have to be regarded as cost-effective. A direct comparison of the SCIT (Allergovit) and SLIT (Oralair) showed lower total costs of SCIT vs SLIT for Austria, Spain, and Switzerland (€1,368 vs €2,012, €2,229 vs €2,547, and €1,901 vs €2,220) and superior effectiveness (SCIT =8.02 QALYs; SLIT =7.98 QALYs; and symptomatic therapy =7.90 QALYs).

Conclusion: In patients with allergic rhinitis, SIT offers cost-effective treatment options compared to symptomatic treatment. When comparing SCIT (Allergovit) and SLIT (Oralair), SCIT was dominant in terms of QALYs as well as costs, in particular due to a slightly higher patient compliance and lower drug costs.