Associations between ICS-based maintenance treatment and asthma outcome (asthma control, asthma exacerbation hospitalization and emergency department visit) in real world: data from CARN study

Background ICS-based maintenance treatment was the basic treatment of asthma. Nevertheless, data of real-world study of ICS-based maintenance treatment on asthma outcome was limited. Methods Based on a national survey on asthma control and disease perception (CARN-2015-01 study), we analysed the impact of ICS-based maintenance treatment on asthma outcome: asthma control, annual incidence of asthma exacerbation hospitalization and emergency department visit in China. Results Altogether 3875 asthmatic outpatients were recruited. 66.7% (2583/3875) asthma patients chose ICS-based maintenance treatment as daily maintenance treatment. After adjusting for confounding factors (age, height, weight, BMI, smoking status, comorbidities, etc), ICS-based maintenance treatment was associated with better asthma control level [OR = 0.542, 95%CI (0.476, 0.617)], higher annual incidence of asthma exacerbation hospitalization [OR = 1.501, 95%CI (1.271, 1.773)] and higher annual incidence of emergency department visits [OR = 1.272, 95%CI (1.074, 1.507)]. In subgroup analysis, in well-controlled asthma patients, there was no statistical difference on annual incidence of asthma exacerbation hospitalization and emergency department visits. In partly controlled asthma patients, patients with ICS-based maintenance treatment have significantly higher annual incidence of asthma exacerbation hospitalization (31.9% vs. 22.5%, P < 0.001) and higher annual incidence of emergency department visits (24.1% vs. 19.1%, P = 0.013). In uncontrolled asthma patients, patients with ICS-based maintenance treatment have significantly higher annual incidence of asthma exacerbation hospitalization (44.7% vs. 28.5%, P < 0.001) but showed no statistical difference on annual incidence of emergency department visits (39.0% vs. 32.4%, P = 0.051). Conclusions ICS-based maintenance treatment was associated with better asthma control level, higher annual incidence of asthma exacerbation hospitalization and higher annual incidence of emergency department visits. During the process of ICS-based maintenance treatment, improvement of symptom control might be prior to the decrease of exacerbation risk.