Quantitative relationships between cigarette smoking and chronic productive cough.

A close relationship between chronic productive cough and cigarette smoking was confirmed in an epidemiological study of airways obstructive disease in Tucson. Pack-years of smoking was closely related to symptom frequency and no threshold effect was noted. This relationship was affected by age and a history of childhood respiratory disease, but not by atopy. Among present smokers males and females did not differ significantly in their smoking habit specific rates of chronic productive cough, but males appeared to lose their symptoms less regularly than females when they quit smoking after many pack-years of cigarette use. When the relationship of smoking to chronic productive cough was removed, smoking was not significantly related to other aspects of 'chronic nonspecific respiratory disease' in this analysis.