Measuring the effect of azithromycin in chronic respiratory disease using continuous cough monitoring: an open-label exploratory trial.

Background: Azithromycin is beneficial in a multitude of respiratory diseases; however, its effects on both subjective and objective measures of cough have been less extensively studied. Traditional 24-h cough counting assessments are highly variable, potentially underestimating the antitussive effect of therapeutics. Methods: Patients with asthma, COPD, interstitial lung disease and refractory chronic cough who reported cough as the predominant symptom were continuously monitored using a smart watch equipped with Hyfe cough detection software. Patients were monitored 1 week prior to and 4 weeks after commencing azithromycin. Participants were also assessed using patient-reported outcome measures and a 4-week daily cough visual analogue scale diary. Cough data were analysed using the novel cough metrics "relief of cough" and "cough density". Results: 30 participants with a broad range of respiratory diseases were recruited; 80% (n=24) had satisfactory usage of the cough monitor (>12 h·day Conclusion: This is the first study to assess the antitussive effect of a drug using continuous cough monitoring. Further trials should use this method of cough assessment to obtain a more granular assessment of cough in airways diseases.