Burden of obstructive lung disease in Iran: Prevalence and risk factors for COPD in North of Iran

Globally chronic obstructive pulmonary disease (COPD) was reported as the fourth leading cause of death (5.1%) in 2004 and is projected to occupy the third position (8.6%) in 2030. The goal of the present project is to describe the prevalence and risk factors of COPD in a province in the north of Iran. Methods: This study followed a stratified cluster sampling strategy with proportional allocation within strata. The stratification of the sample according to the 31 provinces of Iran is incorporated in the sampling process. The single most important outcome measure obtained as part of this protocol was spirometry before and after the administration of 200 mg (2 puffs) of salbutamol. The descriptive statistics for categorical variables included the number and percent and for continues variables included the mean ± SD. Results: A total of 1007 subjects were included in the study. Among all participants, 46 (5%) subjects had COPD on the basis of symptoms and 43 (8.3%) subjects had COPD on the basis of spirometry criteria. In univariate analysis, urban inhabitants in comparison with rural inhabitants had lower COPD risk (OR: 0.48; 95% CI: 0.24-0.95), smoker had higher risk compared with nonsmokers (OR: 1.97; 95% CI: 1.01-3.82), and subjects with exposure to dust (OR: 2.07; 95% CI: 1.09-3.94) had higher risk compared with contrary status. Conclusions: This study showed that occupational and environmental smoke exposure was associated with COPD. A new design of preventive measures must be taken to control cooking energy and cooking stoves, particularly in rural areas.