TOPLINE:

Adults with undiagnosed respiratory diseases such as asthma or chronic obstructive pulmonary disease (COPD) exhibited more severe cough than those with normal spirometry or preserved ratio impaired spirometry (PRISm). A higher severity of cough was associated with poorer quality of life (QOL) and worse sleep quality.

METHODOLOGY:

• Researchers conducted a prospective study to assess the association between cough in adults with undiagnosed respiratory symptoms and its impact on QOL and sleep quality.
• They analyzed data from the UCAP case-finding study conducted across 17 sites in Canada that recruited adults aged 18 years or older with respiratory symptoms and no history of a diagnosed lung disease from June 2017 to January 2023.
• Overall, 2857 adults with respiratory symptoms such as shortness of breath, wheezing, sputum or mucus production, or prolonged cough within the previous 6 months, along with 231 age-matched control individuals, were included.
• Participants completed the Asthma Screening Questionnaire, COPD Assessment Test, and St. George Respiratory Questionnaire to develop a cough score and the 36-item Short-Form Survey and Global Sleep Assessment Questionnaire to assess health-related QOL and sleep quality, respectively.
• They also underwent pre- and post-bronchodilator spirometry and were classified as having asthma, COPD, PRISm, or normal spirometry.

TAKEAWAY:

• Participants with normal spirometry had significantly higher cough scores (mean score, 57.8; 95% CI, 56.9-58.6) than age-matched control participants (mean score, 17.7; 95% CI, 15.6-19.8).
• Among symptomatic participants, those with undiagnosed asthma (n = 265; mean score, 61.0; 95% CI, 58.2-63.7) and undiagnosed COPD (n = 330; mean score, 61.8; 95% CI, 59.3-64.3) had higher cough scores than those with PRISm (n = 172; mean score, 54.5; 95% CI, 51.1-58.0).
• Higher cough scores were associated with poorer QOL (adjusted regression coefficient, -0.19; P < .001) and worse sleep quality (adjusted regression coefficient, 0.16; P < .001).

IN PRACTICE:

“Spirometry-based assessment of individuals in the community with cough and no previously established pulmonary disease may result in earlier diagnoses of obstructive lung disease and may ultimately have positive impacts on patients’ health status and healthcare utilization,” the authors wrote.

SOURCE:

This study was led by Sheojung Shin, MD, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada. It was published online on August 11, 2025, in Annals of the American Thoracic Society.

LIMITATIONS:

The cough score used in this study was not externally validated, and no minimum clinically important difference was determined. The UCAP study predated the widespread adoption of Global Lung Function Initiative equations and instead used prediction equations developed specifically for the Canadian population. 

DISCLOSURES:

This study was funded by The Ottawa Hospital Foundation and a grant from the Canadian Institute of Health Research Foundation. Several authors reported receiving financial aid from and having other ties with multiple pharmaceutical companies including AstraZeneca, GlaxoSmithKline, Valeo, Takeda, and Sanofi.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.