The majority of people with asthma are believed to have "mild" asthma [1]. The term "mild asthma" is usually used to define patients with infrequent or easily relieved respiratory symptoms. However, patients with mild asthma can have severe exacerbations, which, in rare cases, lead to death. The bronchodilatory effects of inhaled short-acting β₂-agonists (SABAs) help to provide rapid respiratory symptom relief in patients with asthma, but SABAs do not address the underlying airway inflammation. Inhaled formoterol is a rapid-onset long-acting β₂-agonist (rapid-onset LABA), but, like SABAs, does not treat the underlying airway inflammation. Several clinical trials have examined the role of as-needed combination therapy with inhaled corticosteroids and formoterol (ICS/formoterol) as an anti-inflammatory reliever (AIR) strategy.

大多数哮喘患者被认为患有“轻度”哮喘[1]。 “轻度哮喘”一词通常用于定义呼吸道症状不常见或容易缓解的患者。然而，轻度哮喘患者可能会严重恶化，在极少数情况下会导致死亡。吸入短效 β2 激动剂 (SABA) 的支气管扩张作用_有助于快速缓解哮喘患者的呼吸道症状，但 SABA 不能解决潜在的气道炎症。吸入福莫特罗是一种速效长效 β2_激动剂（速效 LABA），但与 SABA 一样，不能治疗潜在的气道炎症。几项临床试验已经检验了吸入皮质类固醇和福莫特罗（ICS/福莫特罗）按需联合治疗作为抗炎缓解（AIR）策略的作用。