Economic impact of severe asthma in Spain: multicentre observational longitudinal study

Objective: Estimate the economic impact of severe asthma from the Spanish social perspective through the estimation of the associated annual direct and indirect costs. Methods: Observational, longitudinal, retrospective study carried out in 20 Spanish secondary settings (Pulmonology and Allergy Services) among patients aged >= 18, diagnosed with severe asthma according to European Respiratory Society/American Thoracic Society consensus and who have not experienced an exacerbation in the previous 2 months. Asthma-related healthcare resource utilization as well as asthma-related days off work were collected over a retrospective 12-month period from medical records review (inclusion period: June to November 2016). Total costs were calculated by multiplying the natural resource units used within 1 year by the corresponding unit cost. Costs were expressed in Euros for 2018. Results: A total of 303 patients were included, mean age was 54 years old and 67% were women. There were 5.7 physician visits per patient (3.3 in secondary care). The most common pharmacologic treatment was fixed dose combination of inhaled corticosteroids/long-acting beta 2-adrenergic agonists (96.7%), followed by leukotriene receptor antagonists (57.1%). 134 patients (44.2%) had at least one severe asthma exacerbation (mean: 1.9 exacerbation/patient), of whom 22 patients required hospitalization, with a mean hospital stay of 10.9 days/patient. Mean sick leave due to severe asthma was 9.1 days per patient per year. Mean annual direct cost (confidence interval 95%) was euro7472/patient (euro6578-8612). The cost per exacerbation was euro1410/patient. When indirect costs were added (euro1082/patient [euro564-1987]), the total annual mean cost rose to euro8554/patient (euro7411-10199). Conclusions: Taking the social perspective, the economic impact of severe asthma in Spain was estimated to be euro8554/patient/year.