Economic model
A Markov simulation model with three mutually exclusive nonabsorbent states was used to compare the estimated cost and outcomes associated with asthma management using standard care (SC) or SC with FeNO monitoring to guide asthma management in Children (FeNO-SC) (Figure 1 ). This model and according to the natural history, have three health states were defined: “no symptoms”, “suboptimal, control, no exacerbation”, and “asthma exacerbation” with a cycle length of 1 week. All patients entering the model are children with no symptoms, diagnosed with mild to moderate allergic asthma, and receiving inhaled corticosteroids as maintenance therapy. The effectiveness outcome was the quality-adjusted life years (QALYs). The analysis was carried out from a societal perspective (included direct and indirect costs). The analytic horizon was 12 months. Given the short time horizon, no type of discount to costs or results was applied. The study protocol was reviewed and approved by the Institutional Review Board of University of Antioquia (No 18/2015).