Cost-Effectiveness of Adrenaline Autoinjectors for Children with Food Allergy

Abstract

Children with food allergy live with the risk of anaphylaxis, a life-threatening allergic reaction which requires emergency treatment with an adrenaline autoinjector. The only brand of autoinjector available in New Zealand is the EpiPen, which retails for a minimum of $120 and is not publicly funded. This high price presents a barrier to access, but multiple campaigns by the allergy community have been unsuccessful with the Pharmaceutical Management Agency (PHARMAC) deciding not to prioritise EpiPen funding, potentially due to poor cost-effectiveness in previous analyses. This research aimed to evaluate the cost-effectiveness of EpiPen adrenaline autoinjectors for children with food allergy. Two potential funding strategies were considered: (i) fully-funded EpiPens on individual prescription and (ii) funded school-based EpiPens. A Markov decision-analytic model was built based on the natural history of food-induced anaphylaxis. The model followed a hypothetical cohort of children from five years to 18 years of age or death, through recurrence and treatment pathways. Transition probabilities and utility values were obtained from published literature and expert opinion; costs were estimated from retail and from national and regional funding bodies. Outcomes were expressed as costs incurred and quality-adjusted life years (QALYs) gained. In addition, allergy clinicians and school principals were interviewed about their views regarding funded school-based EpiPens, and a thematic analysis of interview transcripts was carried out. Publicly-funded school-based EpiPens were predicted to be cost-effective at willingness-to-pay thresholds between $2,051 and $8,586 per QALY. Fully-funded EpiPens produced the largest QALY gain and were cost-effective at thresholds above $8,586 per QALY. If either strategy were to be implemented, price negotiations and policy decisions such as the number of devices required per school will affect the thresholds at which each strategy is considered cost-effective. Introducing funded EpiPens is likely feasible and may help alleviate the psychological and financial burden of anaphylaxis for affected families but would require government agencies to prioritise anaphylaxis as a public health issue of importance.