Prevalence of chronic cough in a population based survey

Abstract

Introduction: Chronic cough is a key symptom of many respiratory diseases. The prevalence is not well understood. Most previous surveys have failed to establish whether the duration of cough was 8 weeks or more or have been restricted to narrow age groups. Aims and objectives: Our aim was to establish the prevalence of chronic cough using data from the population based Wythenshawe Community Asthma Project (WYCAP). Methods: Patients registered at 2 practices completed a postal survey based on the European Community Respiratory Health Questionnaire, specifically asking, “Do you have a daily cough that has lasted for eight weeks or more?” We assessed the prevalence and predictors of chronic cough using logistic regression. Results: Out of 11148 adults, 3710 individuals responded to the postal questionnaire (mean age 53.7 years ± 18 years, 55.5% female). The overall prevalence of chronic cough was 16% with no gender difference (females 16.4%, males 15.4% p=0.42). 23.9% were current smokers with 36.1% ex-smokers and 40.1% never smokers. Of patients consenting to the use of their general practice record data (3015 subjects), 6.5% had a diagnosis of COPD, 12% asthma and 5.8% hypothyroidism. In the logistic regression model chronic coughing was significantly more prevalent in current smokers (OR 3.5 (95% C.I 2.7-4.6)), ex-smokers (OR 1.4 (95% C.I 1.1-1.9)), COPD (OR 3.3 (95% C.I 2.3-4.6)), and asthma (OR 2.4 95% C.I 1.8-3.1), but not hypothyroidism. Gender had no influence on prevalence of chronic cough even when interactions with the above were assessed. Conclusions: Our data suggests a significant proportion of the UK population may suffer from chronic cough, most commonly associated with smoking and respiratory disease.