Persons at High-Risk and Low-Risk for Chronic Obstructive Pulmonary Disease: Results from the BOLD Study in Iran

Chronic obstructive pulmonary disease (COPD) is a common, heterogeneous, and largely preventable respiratory condition that is frequently undiagnosed until advanced stages. We estimated the prevalence of COPD risk categories in Iran and examined factors associated with high-risk status.

A population-based survey using stratified cluster sampling was conducted in five major Iranian provinces, representing approximately 36% of the national population. Non-institutionalized adults aged ≥18 years completed standardized questionnaires, SF-12 health-related quality-of-life assessments, and pre- and post-bronchodilator spirometry under the tailored Burden of Lung Disease protocol. Participants were classified as diagnosed COPD (DN), high risk (HR; ≥10 years of tobacco use plus ≥1 respiratory symptom), or low risk (LR).

Among 533 participants (mean age, 53.2 ± 1.83 years; 43.9% men), 5.0% (95% CI: 3.17-6.83) had diagnosed COPD, 13.2% (95% CI: 12.92-13.48) were high risk, and 81.8% (95% CI: 78.55-85.05) were low risk. Dyspnea on exertion (43.6%), productive cough (27.1%), and frequent shortness of breath (32.1%) were common and occurred more frequently in DN and HR groups. High-risk status was more prevalent among men, current smokers, and adults aged >45 years. Tobacco use for ≥10 years was strongly associated with HR classification. Smoking patterns and symptom burden varied substantially across provinces. DN and HR participants had significantly poorer SF-12 physical and mental health scores than LR participants (P<0.001).

A substantial proportion of Iranian adults are at high risk for COPD, indicating an important burden of potentially undiagnosed disease. Targeted screening, smoking-cessation initiatives, and earlier primary-care intervention may improve COPD detection and prevention.