Influence of subcutaneous specific immunotherapy on drug costs in children suffering from allergic asthma

BACKGROUND: Subcutaneous specific immunotherapy (SCIT) is an effective treatment attenuating the progression of allergic asthma. To date, there is a lack of studies investigating the economic consequences of SCIT on health care expenditures. METHODS: A health-economic piggy-back analysis of SCIT was conducted based on a RCT that enrolled 65 children and adolescents with allergic asthma. Patients were allocated into two groups: A group receiving SCIT with a high-dose hypoallergenic house dust mite preparation plus asthma medication and a control group receiving only asthma medication. For both groups asthma control was achieved before the start of the SCIT treatment and was maintained during the study. Both, costs and cost-effectiveness of SCIT with the high-dose hypoallergenic house dust mite preparation were investigated based on total medication costs, incremental medication costs and treatment effects (measured as lung function), respectively. A bootstrap analysis was performed to validate the results. RESULTS: A steady decline in medication costs could be observed in the SCIT group one year after treatment start compared to the control group. This cost trend became statistically significant 3 years after SCIT started. The calculated potential savings in the SCIT group correlated with an improved lung function. The distribution of the bootstrap results revealed that the probability of SCIT having a superior effectiveness compared to the control group is around 90%. CONCLUSION: SCIT with a high-dose hypoallergenic preparation received by children and adolescents suffering from mite induced allergic asthma reduces the allergic medication intake and has cost-saving effects. Additional costs associated with SCIT may be completely compensated by drug cost savings 4 years after end of SCIT. Additionally, SCIT is superior compared to routine care as measured by the lung function that improved in SCIT-treated patients. Trial registration: (EudraCT no. 2004 – 003892 – 35).