Effects of ICS + LABA Combination Therapy on Asthma Control: An Observational Study in Real-World Settings

Background: Inhaled corticosteroids (ICS) combined with long-acting β 2-agonists (LABAs) remain the cornerstone of maintenance therapy in persistent asthma. Although multiple trials have demonstrated short-term efficacy, there is a lack of comprehensive, long-term data on the impact of ICS/LABA therapy on asthma control, exacerbation frequency, and pulmonary function in real-world clinical settings. This study aims to fill this gap by evaluating the effects of ICS/LABA therapy over a 24-month period in a real-world cohort. Methods: We conducted a retrospective cohort study involving 237 adult patients with moderate-to-severe persistent asthma treated at Wuhan Hankou Hospital between January 2021 and December 2023. Eligible participants had ≥ 12 months of documented ICS/LABA use. Patients were evaluated for asthma control using the Asthma Control Test (ACT), frequency of acute exacerbations requiring systemic corticosteroids, pulmonary function (FEV 1 % predicted), and adverse drug reactions. Data were collected at baseline, 12 months, and 24 months. Results: After 24 months, the proportion of patients achieving well-controlled asthma (ACT ≥ 20) increased significantly from 42.6% at baseline to 73.0% (P < 0.001). Mean FEV 1 improved from 72.1 ± 10.4% to 79.8 ± 11.2% predicted (P = 0.002). The annualized exacerbation rate declined from 2.1 ± 1.0 to 0.8 ± 0.6 episodes per patient (P < 0.001). Medication adherence, defined as ≥ 80% refill rate, was significantly associated with greater improvements in ACT and FEV 1 . Reported side effects included oropharyngeal candidiasis (8.0%), dysphonia (5.1%), and tremors (3.8%), but no serious adverse events were documented. Conclusion: Continuous use of inhaled corticosteroids in combination with long-acting β-agonists was associated with sustained improvements in asthma control, enhanced lung function, and a reduction in the frequency of exacerbations. These findings support the continued use of ICS/LABA therapy as an effective and safe strategy for long-term asthma management in clinical practice. Keywords: asthma, inhaled corticosteroids, long-acting β 2-agonists, long-term outcomes, lung function, exacerbation, asthma control test