September 16, 2020
1 min read
Rassouli F, et al. Chronic cough: Only symptom or disease? Presented at: European Respiratory Society International Congress; Sept. 7-9, 2020 (virtual meeting).
This study was funded by CSS Health Insurance. Rassouli reports no relevant financial disclosures.
Nocturnal cough and sleep quality measured by a smartphone app may aid in the prediction of asthma progression, researchers reported at the virtual European Respiratory Society International Congress.
Frank Rassouli, MD, senior physician in pulmonology at the Cantonal Hospital St. Gallen, Switzerland, and colleagues conducted a study to evaluate whether nocturnal cough and sleep quality recorded via a smartphone app could be used to detect periods of uncontrolled asthma or meaningful changes in asthma control. The researchers analyzed questionnaire and sensor data collected for 29 days via a smartphone app from 79 adults with asthma. Researchers used the Pittsburgh Sleep Quality Index and also manually annotated smartphone app audio recordings to measure sleep quality and nocturnal cough frequency each night. For 29 days, participants slept with the smartphone app in use nearby to measure volume of nocturnal coughing.
The primary endpoint was asthma control, as assessed by a weekly version of the Asthma Control Test (ACT). The median weekly ACT score was 21 points over 308 weeks. Participants demonstrated controlled asthma in 192 weeks and uncontrolled asthma in 116 weeks. Researchers observed clinically significant asthma deterioration in 25 participants in 29 weeks.
During 2,004 study days, eight asthma attacks occurred, according to the results.
Mixed-effects regression analyses showed an association between nocturnal cough and sleep quality with asthma control (P < .05).
Sleep quality was a more useful indicator to detect uncontrolled asthma (balanced accuracy: 68% vs. 61%), whereas nocturnal cough was more useful to detect asthma control deterioration (balanced accuracy, 71% vs. 56%).
Researchers predicted asthma attacks 5 days sooner with both markers (balanced accuracy: 70% to 75%).
The researchers plan to assess the smartphone app technology to monitor coughing with patients with COPD, according to a European Respiratory Society press release.
“Our results suggest that nighttime coughing can be measured fairly simply with a smartphone app and that an increase in coughing at night is an indicator that asthma is deteriorating,” Rassouli said in the release. “Monitoring asthma is really important because if we can spot early signs that it’s getting worse, we can adjust medication to prevent asthma attacks.”