Objective cough count in bronchiectasis patients is reproducible and relates to quality of life

Cough is common in bronchiectasis and burdensome to patients. To assess cough as a key treatment target, we examined the reproducibility of cough rates over 2 x 24-hour cough recordings and investigated the association between both day time and night time cough rates, cough related quality of life (Leicester Cough Questionnaire) and sputum volume Six stable bronchiectasis patients completed spirometry, 24-hour ambulatory cough recordings on 2 occasions, LCQ and performed 24-hour sputum collection. Ambulatory cough recordings were counted manually and reported as number of coughs per hour. The mean of each hourly day time and night time cough count is reported Two subjects were female and the mean age was 71.5 (SD 6.4) years. FEV1 was 56.79% (SD18.4), FEV1/FVC was 58.54% (SD10.26%). Daily sputum weight was 20.6g (SD 6.5). Comparing the two recordings, cough rates were reproducible during the day time (r=0.85, p=0.03) but not night time (r=0.48, p=ns). Daytime cough rates were higher (median 21, range 14.2-51.8) than night time (median 6.6, range 0-14.4). A strong correlation was found between daytime cough rate and all domains of LCQ (total p<0.01, physical p<0.01, social p<0.01 and psychological p<0.01) but there was no association with night time cough. Day time cough also correlated strongly with sputum weight (r=0.98, p=0.01) Even in a small number of subjects objective daytime cough count was reproducible and appeared to be related closely to sputum weight and quality of life. In contrast to night time cough which had little relationship. Day time cough frequency has the potential to be a useful marker of disease status in bronchiectasis.