The quality of life of patients with severe asthma differs from mild and moderate asthma partly because of a greater burden of symptoms and risk of exacerbations but also differences in treatment (which can have more pronounced side effects). Because of this, existing asthma specific health related quality of life (HRQoL) scales are not optimally designed for severe asthma patients. The FDA recommends that, in order to ensure content validity, outcome measures should be designed for particular populations.
Recent biologic treatments have reduced the need to use oral corticosteroids in asthma and other treatments. The SAQ is designed so that items measure both the impact of asthma symptoms on quality of life as well as the impact of asthma treatments.