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.