Increased mortality associated with frequent exacerbations in COPD patients with mild-to-moderate lung function impairment, and smokers with normal spirometry

慢性阻塞性肺疾病（COPD）患者，尤其是肺功能轻度至中度受损的患者，以及肺功能正常的吸烟者，频繁的病情加重均会增加死亡率。