The economic costs of severe anaphylaxis in France: an inquiry carried out by the Allergy Vigilance Network.

Background: The prevalence of severe anaphylaxis, between 1 and 3 per 10 000, has increased sharply over recent years, with a rate of lethality of 1%. The economic burden is unknown. Objective: The aim of this study was to estimate the economic costs of anaphylaxis, including direct costs of treatment, hospitalization, preventive and long-care measures, and the indirect cost: absenteeism. Methods: Analysis of 402 patients of anaphylaxis declared by 384 allergists was reported to the Allergy Vigilance Network. The global cost was estimated from the national data of hospital admissions: ICD-10 coding available for 2003, 2004 and 2005. Results: Three work/classroom days were lost per patient. Diagnosis required oral challenge with hospitalization in 18% of cases. The estimated mean total cost was 1895€ for food- and drug-related anaphylaxis (5610€ for the most severe), and 4053€ for Hymenoptera anaphylaxis. National statistics recorded 2575 patients in 2005; 22% more than in 2003. The estimated annual cost was 4 789 500 €. The possible reasons for this being an under-estimate include: data coming only from hospitalized patients, poor identification by medical teams unfamiliar with ICD-10 codes, peri-operative anaphylaxis being insufficiently declared, rush-immunotherapy and maintenance treatments for Hymenoptera anaphylaxis. Similarly, the extra cost of cow milk substitutes, as well as insurance costs where deaths are followed by litigation were not taken into account. Conclusions: The mean cost of anaphylaxis was 1895–5610€ in nonfatal patients. The prevalence was under-estimated because of many biases, leading to underestimation of the national cost. Further studies would be necessary to evaluate the value of preventive strategies.