Recent studies have reported that some Chronic Obstructive Pulmonary Disease (COPD) patients may have a suboptimal ability to generate a sufficient inspiratory effort to achieve adequate lung delivery of inhaled medications through dry powder inhalers. Sparse data is available about the inspiratory capacity of these patients in the home setting, whether clinically stable or when experiencing worsened respiratory symptoms outside the acute care setting. This study is undertaken to better understand the proportion of patients with suboptimal peak inspiratory flow rate (sPIFR) measurements amongst COPD patients receiving dry powder inhaler(s) (DPI) in the ambulatory setting. Further, the study will characterize PIFR over time, the variability of PIFR measurements, and the associations with potential predictors (demographics, clinical, Patient-Reported Outcomes (PRO), body position, and device) as well as exacerbations frequency and change in PIFR around period of exacerbation.

Recent studies have reported that some COPD patients may have a suboptimal ability to generate a sufficient inspiratory effort to achieve adequate lung delivery of inhaled medications through dry powder inhalers. Sparse data is available about the inspiratory capacity of these patients in the home setting, whether clinically stable or when experiencing worsened respiratory symptoms outside the acute care setting. This study is undertaking this study to better understand the proportion of patients with suboptimal peak inspiratory flow rate (sPIFR) measurements amongst COPD patients receiving dry powder inhaler(s) (DPI) in the ambulatory setting. Further, the study will characterize PIFR over time, the variability of PIFR measurements, and the associations with potential predictors (demographics, clinical, PRO, body position, and device) as well as exacerbations frequency and change in PIFR around period of exacerbation. To complete these aims, 120 participants will be enrolled in a 6 month study to perform PIFR measurements and respiratory questionnaires at home.

Inclusion Criteria:

• Age > 50 years-old
• Spirometry-confirmed diagnosis of COPD (FEV1/FVC <0.70)
• Global initiative for Chronic Obstructive Lung Disease (GOLD) II-IV based on spirometry results
• COPD Assessment Test (CAT) score > 10
• For high resistance DPI, baseline PIFR < 90 L/min (InCheck DIAL®) and >=30 L/min; for medium resistance DPI, PIFR ≤ 90 L/min (InCheck DIAL®) and >=60 L/min. Handihaler is a high resistance DPI. Examples of medium resistance DPI: Anoro, Incruse, Breo Ellipta®, Advair® Diskus® DP or Wixela® Inhub®
• History of smoking tobacco products > 10 pack years
• Prescribed at least one daily maintenance DPI with no change in prescription within the four weeks prior to the Enrollment Visit
• One or more exacerbations of COPD requiring systemic corticosteroids within last 2 years

Exclusion Criteria:

• Inability to demonstrate proper technique for the InCheck DIAL® device
• Inability to achieve minimum PIFR for prescribed DPI(s) at screening/enrollment visit (< 30 L/min for e.g., Handihaler® (High resistance DPI), < 60 L/min for Ellipta® (Medium resistance DPI))
• Inability to perform spirometry to meet American Thoracic Society standards
• Neuromuscular disease associated with weakness
• Any condition that, in the opinion of the site investigator, would compromise the subject's ability to participate in the study.
• Pneumothorax within the past 4 weeks
• For those participants who will require spirometry (i.e., if they have not had it within the past 3 months): Participants who present with a myocardial infarction or eye, chest or abdominal surgery within six weeks of baseline can be rescreened after the six week window has passed

From Screening when participants signed Informed Consent through last completed study visit, a total of up to approximately 6 months.