OBJECTIVES: The aim of this presentation is to draw a whole picture of the epidemiology and burden of severe asthma (SA) by using data from three studies with different data sources in Japan.

METHODS: Three data sources (all GSK sponsored studies) were: medical records/claim data of the Kyoto University Hospital (HOSPITAL; HO1515492), health insurance claim database (CLAIM, population based; HO1616484), and Diagnosis Procedure Combination database (HO1617890; DPC, hospital based)]. Asthma patients ≥ 15 years of age were identified by International Classification of Disease, 10^th revision codes and prescription data of asthma management. We assessed proportion of SA among persistent asthma (CLAIM, DPC), distribution of blood eosinophil count among SA (HOSPITAL), risk factors for exacerbations (HOSPITAL, CLAIM), asthma-related direct cost (HOSPITAL, CLAIM, DPC).

RESULTS: An increasing proportion of SA among asthma patients was observed with 0.6-3.6% (15 to 65 years of age, CLAIM) and 6.6-13.4% (15 to 90+ years of age, DPC), and 34% of SA had a blood eosinophil count ≥300 cells/µl (HOSPITAL). Exacerbation history (HOSPITAL, CLAIM) and asthma severity (CLAIM) were associated with subsequent exacerbations. Large economic burden was shown among SA (HOSPITAL, CLAIM, DPC).

CONCLUSIONS: We showed a more complete picture of the epidemiology and burden of SA. Combining different pieces of information from multiple data sources can be useful to complement limitations of each database and answer complex research questions.