Prevalence and Population-Attributable Risk for Chronic Airflow Obstruction in a Large Multinational Study.

Area of Science:

• Respiratory Medicine
• Epidemiology
• Public Health

Background:

• Chronic Obstructive Pulmonary Disease (COPD) is a leading cause of death and disability globally.
• Smoking and air pollution are identified as primary drivers of COPD.
• Chronic airflow obstruction (CAO) is a key quantifiable characteristic of COPD.

Purpose of the Study:

• To estimate the attributable risk of chronic airflow obstruction (CAO) due to various risk factors.
• To analyze the prevalence of CAO across different global sites.
• To identify the relative importance of risk factors for CAO in diverse populations.

Main Methods:

• Cross-sectional study (Burden of Obstructive Lung Disease - BOLD) of 28,459 adults aged ≥40 across 41 global sites.
• CAO defined as postbronchodilator FEV1/FVC ratio < lower limit of normal.
• Bayesian hierarchical models used to estimate local relative risks and population attributable risks.

Main Results:

• Mean CAO prevalence was 11.2% in men and 8.6% in women.
• Mean population attributable risk for smoking was 5.1% (men) and 2.2% (women).
• Other significant risk factors included poor education, dusty occupations (≥10 years), low BMI, and tuberculosis history.

Conclusions:

• Smoking is the primary risk factor for CAO, but its impact varies geographically.
• In certain regions, poor education, low BMI, and passive smoking are more significant contributors to CAO.
• Occupational dust exposure and tuberculosis are notable risk factors in specific locations.