Rationale. Data on the prevalence and determinants of chronic cough (CC) are scarce and originate mainly from Europe and East Asia. In addition, there is huge heterogeneity in the definition and protocols used to assess CC. The aim of this study was to estimate the prevalence and determinants of CC across several world regions using a standardized protocol.
 
Methods. This study is based on data from 28,639 adults (?40 years) from the multinational Burden of Obstructive Lung Disease (BOLD) study. These participants were recruited from 41 sites across 34 countries. All participants completed a questionnaire covering information on respiratory symptoms, diagnoses, smoking as well as other potential risk factors. CC was defined as cough on most days for at least 3 months each year. To identify CC determinants, logistic regression was used to model the association between CC and several variables, adjusted for potential confounders. This was conducted within each site and then meta-analysed. The population attributable risk associated with each of the identified determinants was also estimated.

Results. The mean prevalence of CC was 11.8%, but there was wide variation ranging from 3% in Pune (India) to 24% in Lexington (KY, USA). CC was associated with female sex, smoking, working in a dusty job, a history of tuberculosis, obesity, a low level of education, hypertension and airflow limitation. The most influential risk factor was smoking followed by working in a dusty job.

Conclusion. Our findings show marked regional differences in the prevalence and determinants of CC worldwide. These suggest that more attention should be given to the management of CC to attenuate the societal burden associated with this condition.