Voice as biomarker for early exacerbation detection in asthma and COPD: the TACTICAS study

Early detection of exacerbations of asthma or chronic obstructive pulmonary disease (COPD) increase the chances of positive treatment outcomes. In the TACTICAS study, a prospective cohort study, we investigated if voice changes during an exacerbation and which voice features signify the onset of an exacerbation. In a cohort of 73 participants (35 asthma, 38 COPD) with a mean age of 62 years, daily voice was collected at home on their own mobile devices for 3 months. Simultaneously, the time course (onset, peak and recovery) of an exacerbation was captured using the EXACT® questionnaire. We performed a random intercept multilevel analysis to investigate changes in 39 speech features during onset (first day of exacerbation), peak (day of highest symptoms burden) and recovery (symptom relief). A total of 38 exacerbations from 35 participants were captured within the study period, most mild and moderate in severity. Voice changes already occurred at exacerbation onset, where 13 features had a significant fixed effect. Specifically, features such as the duration of sustained vowels decreased, while shimmer (irregularity of vocal fold vibrations) and Noise-to-Harmonics Ratio increased, indicating the deterioration of overall voice quality during an exacerbation. In conclusion, we found that voice significantly changes during an exacerbation of asthma or COPD, and this occurs as early as at exacerbation onset. These findings highlight the potential of voice as biomarker for early detection and management of exacerbations. It also addresses the unmet need of remote patient monitoring via mobile devices in the home environment using novel digital biomarkers.