Asthma and COPD are two common chronic airway diseases associated with high morbidity and mortality [1, 2]. It is estimated that approximately 20% of asthma and COPD have diagnosis or features of both [3]. There is growing appreciation of the need to tease out phenotypes and endotypes across the spectrum of chronic airway diseases [4, 5], to evolve towards precision medicine [6, 7]. While there have been recent large cohort studies following either severe asthma [8] or COPD [9], there is paucity of large real life longitudinal studies investigating both asthma and COPD together with the asthma/COPD overlap across the all disease severity spectrum without any predetermined pharmacological intervention.

哮喘和 COPD 是两种常见的慢性气道疾病，与高发病率和死亡率相关 [1, 2]。据估计，大约 20% 的哮喘和 COPD 具有两者的诊断或特征 [3]。人们越来越意识到需要梳理慢性气道疾病 [4, 5] 的表型和内型，以向精准医学发展 [6, 7]。虽然最近有针对严重哮喘 [8] 或 COPD [9] 的大型队列研究，但在现实生活中调查哮喘和 COPD 以及哮喘/COPD 在所有疾病严重程度范围内重叠的大型纵向研究很少，没有任何预定的药物干预。