Adherence to inhaled treatment is associated with better disease control and quality of life in mild-to-moderate asthma

Background: Asthma is a common chronic disease worldwide, with most patients presenting with mild to moderate forms. Poor adherence to inhaled therapy is a recognized determinant of worse outcomes in chronic respiratory diseases. The aim of this study was to evaluate adherence to inhaled medications in a large cohort of adults with mild to moderate asthma and identify factors associated with suboptimal adherence. Methods: This cross-sectional real-world study analyzed data from the Mild-Moderate Asthma Network of Italy (MANI) database. Adult patients (≥18 years) with a confirmed diagnosis of asthma according to Global Initiative for Asthma (GINA) criteria were eligible. Data from the first visit in which the Test of Adherence to Inhalers (TAI) questionnaire was available were extracted. Patient-reported outcomes included the Asthma Control Test (ACT), the Asthma Quality of Life Questionnaire (AQLQ), and TAI adherence categories. Patients were classified into three classes according to TAI score as follows: adherents (score ≥50), intermediate adherents (score 46–49), and non-adherents (score <46). Results: A total of 832 patients were included. Adherent patients were older than intermediate and non-adherent subjects (p < 0.001). Current smoking was less frequent among adherent patients (11% vs 16%). Type 2 diabetes and anxiety were more prevalent among non-adherent individuals (5.3% vs 0.8% and 1.8%, p = 0.014; 10.7% vs 7.1% and 3.8%, p = 0.003, respectively). Higher adherence levels were associated with better asthma control (χ2 (2) = 47.706, p < 0.001) and quality of life (χ2 (2) = 42.068, p < 0.001). Conclusion: In adults with mild to moderate asthma, better adherence to inhaled therapy is associated with improved disease control and quality of life. Demographic factors, smoking status, and comorbidities may influence adherence behaviors. Routine assessment of adherence and targeted interventions addressing modifiable barriers may improve outcomes in this large asthma population.