Cost-effectiveness of Oral Immunotherapy for Egg Allergy According to Age of Therapy Commencement

Background: Egg oral immunotherapy (OIT) can induce desensitization or remission of egg allergy in children. 

Objective: To determine the cost-effectiveness of OIT for raw egg allergy in school-age children compared with egg avoidance, and the most cost-effective age at which to commence treatment. 

Methods: A decision-analytic Markov model estimated the health and cost outcomes of 1,000 children aged 4 years with egg allergy, comparing different ages of OIT commencement (ages 4-12, inclusive) versus ongoing egg avoidance. Years lived with egg allergy, egg tolerance or remission (natural and OIT-induced), and desensitization to egg were captured, with rates of allergic reactions and utility values assigned to each health state. Treatment effects were derived from published randomized clinical trials and meta-analyses. The main outcome was the incremental cost-effectiveness ratio (ICER) from the Australian health care payer perspective (costs in Australian dollars per quality-adjusted life-year [QALY] gained), with a 20-year time horizon, 5% annual discounting, and an AU $50,000/QALY willingness-to-pay (WTP) threshold. Results: Without OIT, 858 children attained natural resolution before age 24. Under conservative assumptions, with OIT-induced remission set at zero and 84% achieving desensitization, ICERs were below the WTP threshold for treatment commencement at age 8 or older, with the smallest ICER observed at age 12 (AU $43,233/QALY; 95% CI, 32,025-73,350). However, the cost-effectiveness of OIT was achieved at all ages (ICER less than the WTP threshold) when OIT-induced remission increased to ∼40% of treated children. 

Conclusions: Based on current published evidence, the cost-effectiveness of egg OIT improves with increased age of treatment commencement. Cost-effectiveness increases when the proportion of children achieving OIT-induced remission increases.