Domiciliary Cough Monitoring for the Prediction of COPD Exacerbations

Acute exacerbations of COPD (AE-COPD) are a leading cause of health service utilisation and are associated with morbidity and mortality. Identifying the prodrome of AE-COPD by monitoring symptoms and physiological parameters (telemonitoring) has proven disappointing and false alerts limit clinical utility. We report objective monitoring of cough counts around AE-COPD and the performance of a novel alert system identifying meaningful change in cough frequency.

This prospective longitudinal study of cough monitoring included chronic obstructive pulmonary disease (COPD) patients experienced in telemonitoring that had two or more AE-COPD in the past year. Participants underwent cough monitoring and completed a daily questionnaire for 90 days. The automated system identified deteriorating trends in cough and this was compared with alerts generated by an established telemonitoring questionnaire.

28 patients [median age 66 (range 46-86), mean FEV-1% predicted 36% (SD 18%)] completed the study and had a total of 58 exacerbations (43 moderate and 15 severe). Alerts based on cough monitoring were generated mean 3.4 days before 45% of AE-COPD with one false alert every 100 days. In contrast, questionnaire-based alerts occurred in the prodrome of 88% of AE-COPD with one false alert every 10 days.

An alert system based on cough frequency alone predicted 45% AE-COPD; the low false alert rate with cough monitoring suggests it is a practical and clinically relevant tool. In contrast, the utility of questionnaire-based symptom monitoring is limited by frequent false alerts.