OBJECTIVES: In vitro diagnostic (IVD) has a considerable health economic impact: 60% of patients’ information derives from IVD tests, but IVD makes 1% of the total health care budget in EU (EDMA, 2010). No cost-effectiveness (CE) analyses are available on molecular IVD in allergy; only NICE in the UK made a CE study IgE IVD for peanut allergy (PA). Given the impact of PA on quality of life (Qaly), accurate diagnosis is crucial. 10% of children are considered peanut sensitised, but only 1-2% is true positive for PA. Subjects with IgE antibodies to allergens Ara h1-2-3 have high risk of allergic reactions (Astier, 2006).   DBPCFC is the gold standard for food-allergy diagnosis; however it is time-consuming, expensive and might induce severe reactions (Nicolau, 2010). IVD can give clinicians a tool to decide the need of DBPCFC (Sastre, 2010); is IVD CE compared to DBPCFC in suspected PA children in EU, US and Japan? METHODS: Data was collected at Stockholm’s Sach´s Children's hospital (Nilsson, 2011) and from published literature. A 5-year Markov simulation model comparing IVD (ImmunoCap® - allergens f13, Ara h 1- 2-3-8-9) with DBPCFC was developed with Tree AgePro®, to analyse CE for IVD and the incremental cost per Qaly in suspected PA children. The sensitivity and specificity of each diagnostics determines the percentage of patients true-allergic, false-allergic, true-healthy and false-healthy. BaseCase® was used to interactively visualize results. Results are presented from the health care perspective; care giver indirect costs are included in a sensitivity analysis. RESULTS: IgE IVD is CE and cost saving for children with suspected PA in multiple countries compared to golden standard DBPCFC. CONCLUSIONS: IVD is a CE alternative to DBPCFC in selected patients in multiple countries. DBPCFC might be replaced in selected cases, still being useful in subjects with conflicting immunological/clinical results (Codreanu, 2011).