Variations in the prevalence across countries of chronic bronchitis and smoking habits in young adults

The present work aims to assess the international variation in the prevalen ce of chronic bronchitis and its main risk factor, smoking habits, in young adults of 35 centres from 16 countries. Respiratory symptoms and pulmonary function were assessed in 17,966 subject s (20-44 yrs), randomly selected from the general population. in the frame of the European Community Respiratory Health Survey. The median prevalence of chronic bronchitis was 2.6%, with wide variations across countries (p <0.001; 0.7-9.7%). The prevalence of current smokers ra nged 20.1-56.9%,) (p <0.001) with a median value of 40%. Current smoking wa s the major risk factor for chronic bronchitis. especially in males. Its ef fect increased according to number of pack-yrs: in males, the odds ratio of chronic bronchitis was 3.51 (95% confidence interval (CI) 2.31-5.32) in 1- 14 pack-yrs smokers and increased to 17.32 (9.97-30.11) in greater than or equal to 45 pack-yrs smokers with respect to nonsmokers. Only 30% of the ge ographical variability in prevalence could be explained by differences in s moking habits, suggesting that other environmental and/or genetic factors m ay play an important role. In conclusion, chronic bronchitis is a substantial health problem even in y oung adults. The impressive prevalence in current smokers in most countries highlights the need to improve the quality of prevention.