Clinical Differences between Early- and Late-Onset Asthma: A Population-Based Cross-Sectional Study.

"Disclosure This work has been previously presented as a poster at the American Thoracic Society International Conference, 2020. Conflicts of Interest The authors declare that they have no conflicts of interest."

"The authors thank Prof. Zhu Lei for pulmonary function test instruction and Zhifeng Zhang for technical assistance. The authors acknowledge Prof L. Shi and C. Bai for their assistance in data collection. This work was sponsored by Shanghai Municipal Key Clinical Specialty (shslczdzd02201) and Shanghai Top-Priority Clinical Key Disciplines Construction Project (2017ZZ02013); National Natural Science Foundation of China (81770075); Science and Technology Commission of Shanghai Municipality (20XD1401200 and 20Z11901000); and National Key R&D Plan (2020YFC2003700); SJ was sponsored by the Shanghai Pujiang Program (16PJD012)."