The goal of this non-pharmacologic interventional study is to learn if Oscillatory Positive Expiratory Pressure (OPEP) therapy can improve disease impact and respiratory system dynamics in patients with COPD. The main questions it aims to answer are:

Is OPEP therapy able to improve the impact of cough symptoms as measured on a validated symptom score? Is OPEP therapy able to improve the properties of the lung (called reactance) as measured by oscillometry?

Researchers will compare the results of the same tests performed before and after 4 weeks of OPEP treatment to see if OPEP treatment improves cough symptoms and lung mechanics.

• Participants with COPD will complete in-person baseline tests and will then receive the smart OPEP device.
• These participants will then use the smart OPEP device at home, at least twice a day, for 4 consecutive weeks.
• Finally, these participants will return to complete in-person end-of-study tests.

The objectives of this prospective, non-pharmacologic interventional cohort study are to determine the effect of four consecutive weeks of twice-daily or greater OPEP usage among patients with COPD with a chronic bronchitis (sputum-producing) phenotype on disease impact and on respiratory system dynamics. A 'dose-response' effect of OPEP use will also be investigated.

We hypothesize that a 4-week period of OPEP therapy among eligible patients with COPD with a chronic bronchitis (sputum-producing) phenotype will be associated with improved disease impact scores and airway mechanics.

Inclusion Criteria:

1. Males and females 40 years of age or more
2. Former/current smokers with a cigarette smoking history for 10 or more pack-years
3. Physician diagnosis of COPD previously confirmed by spirometry (FEV1/FVC less than 0.7) with 'mild' to 'very severe' (i.e. GOLD 1-4) COPD
4. Chronic bronchitis phenotype: Sputum production or presence of productive cough greater than 2 days/week in the last 3 months for at least 2 consecutive years, or presence of cough and phlegm almost every day or several times per week
5. Ability to participate without supplemental oxygen during all oscillometry testing
6. Ability to provide informed consent

Exclusion Criteria:

1. No COPD diagnosis
2. Bronchiectasis, cystic fibrosis, or any other known suppurative acute/chronic lung disease as the principal respiratory condition
3. Physician-diagnosed exacerbation and/or hospitalization for pulmonary symptoms in the 4 weeks preceding baseline testing
4. Current use of OPEP, or any use of OPEP in the 4 weeks preceding baseline testing
5. Current or recent participation in a standard Pulmonary Rehabilitation program in the 4 weeks preceding baseline testing or during the study

Due to data privacy regulations, individual participant data collected during this study is not publicly accessible. However, access to anonymized data may be granted upon evaluation. Additional documents will also be available upon inquiry. All requests should be directed to the corresponding author (BAR).