Effect of Spacer Use on Exacerbation Risk in High-Risk Older Adults With Chronic Airway Diseases Receiving Triple Therapy

Inclusion Criteria: 1. Age ≥65 years, no gender restriction; 2. Confirmed diagnosis of chronic obstructive pulmonary disease (COPD) based on GOLD criteria or bronchial asthma based on GINA criteria; 3. Currently on stable treatment with fixed-dose combination ICS/LABA/LAMA via pMDI for ≥4 weeks; 4. History of any of the following in the past 12 months: 1. ≥1 hospitalization due to exacerbation, or 2. ≥2 moderate exacerbations requiring systemic corticosteroids and/or antibiotics; 5. Able to complete inhalation technique training and demonstrate basic communication and device-handling abilities; 6. Provides written informed consent to participate in the study. Exclusion Criteria: 1. Use of other inhalation devices as primary therapy (e.g., DPI, SMI, or nebulizer); 2. Regular use of a spacer device for ≥3 weeks within 3 months prior to enrollment; 3. Current or recent (within 4 weeks) acute exacerbation not fully resolved; 4. Severe cognitive impairment (MMSE score \<18); 5. Presence of severe systemic comorbidities (e.g., end-stage malignancy, advanced heart failure, hepatic or renal failure); 6. Participation in another interventional clinical trial; 7. Inability to use a mouthpiece-based spacer (e.g., structural oral/facial abnormalities, severe anxiety); 8. Known allergy or hypersensitivity to spacer device materials.