Risk Factors for Chronic Cough Among 14,669 Individuals From the General Population

BACKGROUND: Risk factors for chronic cough in the general population have not been described systematically. We identified and ranked chronic cough risk factors at the individual and community level using data from 14,669 individuals from the Copenhagen General Population Study.

METHODS: Severity of chronic cough was assessed using the Leicester Cough Questionnaire (LCQ). We ranked chronic cough risk factors based on magnitude of age-adjusted ORs at the individual level and of the population attributable risks (PARs) at the community level.

RESULTS: Prevalence of chronic cough in the general population was 4% overall and 3% in never smokers, 4% in former smokers, and 8% in current smokers. Median score of the LCQ was 5.8 (25th-75th percentile, 5.0-6.3) for physical domain, 5.6 (25th-75th percentile, 4.6-6.3) for psychologic domain, 6.3 (25th-75th percentile, 5.5-6.8) for social domain, and 17.3 (25th- 75th percentile, 15.4-18.9) in total. At the level of the individual, age-adjusted ORs for the three top-ranked risk factors were 5.0 (95% CI, 1.4-18) for bronchiectasis, 2.6 (95% CI, 1.7-3.9) for asthma and 2.3 (95% CI, 1.5-3.4) for gastroesophageal reflux disease in never smokers, 7.1 (95% CI, 2.6-20) for bronchiectasis, 3.1 (95% CI, 2.2-4.4) for asthma and 2.2 (95% CI, 1.5-3.2) for occupational exposure to dust/fumes in former smokers, and 1.9 (95% CI, 1.3-2.9) for airflow limitation in current smokers. At the level of the community, the three top-ranked risk factors were female sex (PAR, 19%), asthma (PAR, 10%), and gastroesophageal reflux disease (PAR, 8%) in never smokers; abdominal obesity (PAR, 20%), low income (PAR, 20%), and asthma (PAR, 13%) in former smokers; and airflow limitation (PAR, 23%) in current smokers.

CONCLUSIONS: Risk factors for chronic cough differ at the level of the individual and community, and by smoking status. Strategies to prevent and treat modifiable chronic cough risk factors should be tailored accordingly.