Retrospective Cohort Study on Asthma With Frequent Acute Attacks Phenotype

1. Identify the risk factors for frequent acute exacerbations of asthma: establish a retrospective study, classify patients into frequent acute exacerbation group and non-frequent acute exacerbation group based on the number of acute exacerbations, analyze the characteristics of the two groups, provide clinical, pathological, and comorbidity features of the frequent acute exacerbation subtype of asthma, determine the risk factors associated with frequent acute exacerbations, and establish a disease prediction model for frequent acute exacerbations of asthma. 2. Observe the prognosis and treatment outcome of patients with frequent acute exacerbations of asthma, clarify the relevant factors for poor prognosis in this group of patients, and explore individualized treatment plans to improve the prognosis of patients. 3. Investigate the inflammatory mechanism of frequent acute exacerbations of asthma: use omics methods to screen for subtype-specific biomarkers of frequent acute exacerbations and validate them, clarify the pathogenesis of this subtype, and discover new specific treatment targets.