Objective markers for asthma that can be measured without extra patient effort could mitigate current asthma monitoring shortcomings. We investigated whether smartphone-recorded nocturnal cough and sleep quality can be utilized to detect periods with uncontrolled asthma or meaningful changes in asthma control and for the prediction of asthma attacks.

We analyzed the questionnaire and sensor data of 79 adults with asthma. Data was collected in situ for 29 days utilizing a smartphone. Sleep quality and nocturnal cough frequencies were measured every night with the Pittsburgh Sleep Quality Index and manually annotating coughs from smartphone audio recordings. The primary endpoint was asthma control assessed with a weekly version of the Asthma Control Test. The secondary endpoint was self-reported asthma attacks.

Mixed-effects regression analyses showed that nocturnal cough and sleep quality were statistically significantly associated with asthma control on a between- and within-patient level (p < 0.05). Decision trees indicated that sleep quality was more useful for detecting weeks with uncontrolled asthma (balanced accuracy (BAC) 68% vs. 61%; Δ sensitivity − 12%; Δ specificity − 2%), while nocturnal cough better detected weeks with asthma control deteriorations (BAC 71% vs. 56%; Δ sensitivity 3%; Δ specificity − 34%). Cut-offs using both markers predicted asthma attacks up to five days ahead, with BACs between 70% and 75% (sensitivities 75 – 88% and specificities 57 – 72%).

Nocturnal cough and sleep quality have useful properties as markers for asthma control and seem to have prognostic value for the early detection of asthma attacks. Due to the limited study duration per patient and the study’s pragmatic nature, future research is needed to comprehensively evaluate and externally validate the performance of both biomarkers and their utility for asthma self-management.

Ref: https://www.dovepress.com/nocturnal-cough-and-sleep-quality-to-assess-asthma-control-and-predict-peer-reviewed-article-JAA