Derivation of the asthma-related exacerbation ICS response phenotype in GERA. 1Time period between the first and last asthma ICD diagnosis code dates; 2the following prespecified comorbidities were removed: cystic fibrosis, bronchiectasis, chronic obstructive pulmonary disease, pulmonary embolism, primary pulmonary hypertension; 3Subjects with identity-by-descent estimates >0.1875. GERA, Genetic Epidemiology Research on Adult and Aging; ICS, inhaled corticosteroid; OCS, oral corticosteroid.