Prevalence of undetected persistent airflow obstruction in male smokers 40-65 years old.

BACKGROUND

Airflow obstruction in smokers is often diagnosed relatively late. Earlier detection of airflow obstruction and smoking cessation may result in significant health gain.

OBJECTIVE

To determine the prevalence of previously undetected persistent airflow obstruction according to WHO/GOLD criteria in male smokers aged 40 to 65 years and its correlation with age, smoking history and the presence of coughing.

METHODS

In a cross-sectional study among 805 male smokers aged 40-65 years spirometry was performed according to ATS recommendations. In participants with low lung function (FEV1 < 85% predicted) a bronchodilator test was performed.

RESULTS

In 702 participants [mean age 50 years (SD 6.6), mean number of pack years 24.7 (SD 9.6)] with acceptable spirometric curves, previously undetected airflow obstruction was found in 210 subjects (29.9%; 95% CI 26.5-33.4): mild airflow obstruction (GOLD stage 1) in 182 subjects (25.9%; 22.7-29.3) and moderate airflow obstruction (GOLD stage 2) in 28 (4.0%; 2.7-5.7). In the older age group (>55 years) airflow obstruction (GOLD 1 or higher) was found in 45% versus 21% in the youngest age group (40-44 years). In subjects with > or =30 pack years the prevalence of airflow obstruction was 45% versus 20% among those with <20 pack years. In smokers reporting coughing the prevalence was 47% versus 25% in those not reporting this symptom.

CONCLUSION

The prevalence of undetected persistent airflow obstruction in middle-aged smokers is high. Targeted screening therefore, especially in smokers aged 40-65 years needs to be considered.