High ACT score is not sufficient to reduce the risk of asthma exacerbations in asthma with low lung function

Abstract

Background: Low forced expiratory volume in 1 s (FEV1) is a risk factor for asthma exacerbations (AEs). We aimed to determine if asthma control could reduce the future risk of AEs in patients with low FEV1. This study was conducted to evaluate the future risks of AEs within six months according to Asthma Control Test T (ACT) score and FEV1. Methods: A total of 565 patients with asthma were enrolled from the COREA cohort. The ACT score, lung function test, and number of AEs were assessed at baseline, three-month follow-up, and six-month follow-up with conventional asthma treatments by asthma specialists in real clinical settings. Results: Female sex, low ACT score, low FEV1, low FVC, and AE history in the previous three months were related with increased AEs within six months. AEs during six-month follow-up occurred in 24% of patients with ACT < 20 and FEV1 < 60% at baseline. Among patients with an ACT score >= 20, 3.4% of patients with an FEV1 < 2.16 L and 9.8% of patients with FEV1 >= 2.16 L had experienced AEs (P = 0.01), although no differences were observed in the presence of AEs within six months according to the predicted FEV1 (FEV1 >= 60% vs. FEV1 < 60%, 5.66% vs. 8.51%, P = 0.65). Conclusion: Patient with low FEV1 seemed to show higher risk of AEs than those with near-normal FEV1 despite ACT score >= 20 and asthma treatments. Therefore, treatment strategies that prevent AEs are needed in high-risk asthmatic patients.