Respiratory-Responsive Vocal Biomarker for Asthma Exacerbation Monitoring: Prospective Cohort Study (Preprint)

Abstract

BACKGROUND Asthma exacerbations are a significant issue due to poor perception and failure of traditional monitoring techniques to capture real-time changes in respiratory function. There is a need for strategies to enhance recognition and facilitate timely intervention. OBJECTIVE To evaluate the efficacy of a respiratory-responsive vocal biomarker (RRVB), accessible via smartphone application, as a convenient real-time tool for monitoring asthma exacerbations and respiratory states. METHODS In this three-month prospective cohort study, 84 asthma patients recorded daily 6-second vocal samples, generating RRVB scores. The RRVB's ability to predict asthma exacerbations and respiratory states (normal function, mild events, exacerbations) was assessed using risk ratios (RR) and confidence intervals (CIs). Respiratory states were defined using peak expiratory flow (PEF) and self-reported wellbeing, with exacerbations identified by a decline in both PEF and wellbeing, and mild events by a decline in one measure. RESULTS RRVB scores significantly predicted asthma exacerbations, with a risk ratio of 2.15 (95% CI: 1.62-2.85, p < .001), and 3.57 (95% CI: 2.70-4.73, p < .001) using normalized scores adjusted for individual characteristics. However, time-averaged RRVB scores did not significantly correlate with asthma control as measured by the Asthma Control Test (ACT), with a risk ratio of 1.17 (95% CI: 0.96-1.44, p = .12). A total of 58% of participants remained engaged throughout the study, reporting high satisfaction with the tool's usability and perceived benefits for asthma management. CONCLUSIONS This study demonstrates potential enhancements in asthma management through more accessible and continuous monitoring of respiratory function offered by the RRVB tool, which was shown to provide an effective, real-time, and user-friendly approach for detecting potential exacerbations. CLINICALTRIAL clinicaltrials.gov: NCT05850390