Smoking and chronic respiratory symptoms: prevalence in male and female smokers

The relationship between respiratory symptoms and smoking habits, according to sex, was studied in 899 adults (average age 39, 55 per cent male) in a Paris industrial medical center. The relative risk of having chronic bronchitis among smokers, compared to nonsmokers, was higher in females (3.3) than in males (1.6). The prevalence of chronic respiratory symptoms, dyspnoea and wheezing was more closely associated with the number of cigarettes smoked per day in females than in males. No confounding factor was found to be responsible for these results.