The use of objective 24 hour cough monitoring to measure clinical improvement in cystic fibrosis

Abstract

Cough is a common symptom is cystic fibrosis (CF). Many patients demonstrate characteristics of cough hypersensitivity suggesting vagal nerve excitability. The introduction of CF modulator therapy has demonstrated beneficial response in a number of clinical parameters, particularly exacerbation rate and nutritional status. We hypothesised that the improvement in respiratory function with Kaftrio would be associated with a reduction in objectively measured cough. Ambulatory cough monitoring using a 24 hour recording system can be analysed in a semi-automated system (a kind gift from Professor S Birring). We recorded total cough count and average hourly cough count over 24 hours in patients at baseline and 1 month post initiation of Kaftrio. 14 patients were studied with a mean age of 31 years (5 female, 9 male). Total cough counts at baseline ranged from 29-2985 (median of 290) coughs over 24 hours. One month post initiation of Kaftrio objevtive cough counting was reduced in all patients to a range of 8-149 (median 22.5) total coughs over 24hours (p<0.05). These findings illustrate the usefulness of objective 24 hour cough counting in the monitoring of cystic fibrosis patients. The magnitude and speed of change provides a useful guide to therapeutic response and may provide simple objective measurement of clinical improvement in cystic fibrosis.