Identification and validation of asthma phenotypes in Chinese population using cluster analysis

Abstract

Background: Asthma is a heterogeneous airway disease, it is crucial to clearly identify clinical phenotypes to manage asthma better. Objective: To identify and validate the adult asthma clusters in Chinese population. Methods: A prospective 12-month cohort study was undertaken. 284 patients were recruited and 19 variables were included. Hierarchical cluster analysis was performed by Ward9s method followed by k-means cluster analysis. Results: Five clusters were identified with a satisfying performance of silhouette coefficient point (0.2). The cluster 1 (n=62) was characterized by young females, low income and mild asthma with normal lung function, the cluster 2 (n=46) by older female, no health insurance, low education level, unemployed, very low income, allergy, longer asthma duration, and moderate to severe asthma with poor asthma quality of life (AQLQ), the cluster 3 (n=74) by female, high education level and poor lung function, the cluster 4 (n=55) by male, smoking, few health insurance, low income and mild to moderate with normal lung function, and the cluster 5 (n=47) by males, high education level, smoking health insurance, full-time job and mild asthma with normal lung function and better AQLQ. Compared with the cluster 5, the cluster 1 was at higher risk of non-planned visits (RR=2.67, 95%CI=[1.12, 6.32]) and emergency visits (RR=4.06, 95%CI=[1.26, 13.04]), the cluster 2 at higher risk of asthma exacerbations (RR=4.39, 95%CI=[1.63, 11.85]), non-planned visits (RR=9.41, 95%CI=[3.64, 24.30]) and emergency visits (RR=15.47, 95%CI=[4.75, 50.33]). Conclusion: Cluster analysis revealed five distinct asthma phenotypes in Chinese population, which exhibited different asthma outcomes.