This study is for adults with COPD. Flare-ups of COPD, also known as exacerbations, can be serious and lead to hospital stays. The purpose of this research is to see if continuously and automatically monitoring a person's coughs can help predict these flare-ups early, before they become severe. Participants will use the Hyfe cough monitoring system, which includes a watch-like device worn on the wrist and a smartphone application. The system privately counts the number of coughs without recording any audio. Participants will also answer a short, weekly questionnaire about their COPD symptoms. This is an observational study, which means it will not change the regular medical care a participant receives. The participants and their care providers will not see the cough counts. The doctor will continue to manage their COPD as usual.

This is a prospective, multi-center, observational cohort study designed to evaluate the accuracy of a continuous, passive acoustic monitoring system (Hyfe) for the early detection of COPD exacerbations. COPD exacerbations are a major driver of disease progression and healthcare utilization, but current detection methods rely on subjective patient-reported symptoms. Cough is a core symptom of COPD, and its objective quantification may provide an early warning signal for clinical worsening. This study aims to determine if changes in cough frequency, as measured by the Hyfe system, can predict an upcoming exacerbation with a clinically relevant lead time. The study will enroll two cohorts of patients with a COPD diagnosis: outpatients with a history of frequent exacerbations and inpatients hospitalized for a severe exacerbation. Participants will use the Hyfe Cough Monitor Suite to continuously track cough frequency and will complete the COPD Assessment Test (CAT) questionnaire weekly. To ensure an unbiased assessment, treating clinicians will be blinded to all study-collected data (both cough counts and CAT scores). The clinical diagnosis of a COPD exacerbation, as defined by GOLD 2025 criteria and made by the blinded clinician, will serve as the ground truth endpoint.

Inclusion criteria:

• Must be 18 years of age or older.
• Must have an existing diagnosis of COPD.
• For the inpatient cohort, participants must be currently assessed as having a moderate/severe exacerbation.
• For the outpatient cohort, participants must have had at least one exacerbation of any severity in the last 12 months.
• For the outpatient cohort, at least one month must have passed since the last exacerbation.

Exclusion criteria:

• Individuals who are unable to provide informed consent.
• Individuals who are unable to adhere to study procedures.
• For the inpatient cohort, individuals requiring invasive or non-invasive ventilation.
• Individuals who live with a person who has a chronic cough.

The study will enroll adult participants with a confirmed diagnosis of COPD. The population is composed of two distinct groups: inpatients who are currently hospitalized for a moderate/severe COPD exacerbation, and outpatients attending routine follow-up who are selected to enrich the sample with individuals who experience frequent exacerbations.

The study protocol does not outline a plan for sharing IPD with researchers external to the study team. The protocol's dissemination plan is focused on sharing aggregated study results in scientific meetings and through publication in peer-reviewed journals. While anonymized data will be shared with the study's co-investigators and the sponsor, there is no provision for making IPD available to other researchers.