Burden of obstructive lung disease study in Tehran: Prevalence and risk factors of chronic obstructive pulmonary disease

Abstract

Background:Chronic obstructive pulmonary disease (COPD) was ranked the sixth-most common cause of death worldwide in 1990, but now it is the third-most common cause. The goal of the present study was to assess the prevalence and determine the causes and risk factors of COPD in Tehran.Materials and Methods:This study followed a stratified cluster sampling strategy with proportional allocation within strata. The target population was all non-institutionalized inhabitants, aged 18 to 40 in one group and over 40 in another who resided in Tehran in 2013. The core questionnaire was developed from pre-existing validated questionnaires that had already been used in multi-national studies. The single most important outcome measure obtained as part of this protocol was spirometry before and after the administration of 200 mg (two puffs) of salbutamol.Results:The most commonly reported respiratory symptoms were: sputum production in 291 patients (16.2%) [95% confidence interval (CI): 14.5-17.9%], chronic cough in 171 (9.5%) (95% CI: 8.2-10.9%), wheezing in 377 (21.0%) (95%CI: 19.1-22.9%) and dyspnea in 388 patients (21.6%) (95% CI: 19.7-23.5%). The overall COPD prevalence defined by the post-bronchodilator spirometric functional criteria was 9.2%. This value in men (10.1%) was higher than in women (8.5%); the prevalence was significantly higher in subjects aged over 55 years (P ≤ 0.002). The prevalence of COPD was strongly dependent on smoking status, especially in ex-smokers, and increased considerably with age. 69% of patients with COPD were non-smoker.Conclusion:The high prevalence of verified COPD, a great deal of which was undiagnosed before by a physician, highlights the necessity of raising awareness of this disease among health professionals, and use of spirometry in the primary care setting. A future cross-sectional and prospective cohort study should be performed to explore all risk factors and their impact on decline in lung function and worsening of respiratory symptoms especially in non-smokers.

Burden of obstructive lung disease study in Iran: First report of the prevalence and risk factors of copd in five provinces

“…[34] In another study, male sex, increasing age, and smoking history were strong risk factors for COPD, and these associations remained significant after adjustment for other variables. [35] This situation is similar to our previous study in Tehran[13] and posed the hypothesis that considering lower prevalence of tobacco smoking, other risk factors such as air pollution and fossil fuel pollution levels could have a greater effect in women compared with men.…”

“…[101112] In our previous study, we found that the prevalence of airflow limitation was higher in individuals who had ever smoked, but among patients with COPD according to the spirometry tests, 12.6% were smokers and 18.3% ex-smokers. [13] In other words, nonfully reversible airflow obstruction also occurs in never smokers. Iran is a developing country where the smoking rate (11.9%) is lower than the observed in many developed countries.…”

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

“…Smoking and exposure to environmental tobacco smoke have been proved to be the strongest risk factors for airflow obstruction,[ 12 ] but many areas of the world with high mortality rates from “COPD” still have low consumption of tobacco, implying that tobacco smoking alone does not explain the distribution of COPD. [ 13 14 15 ] In our previous studies, we found that the prevalence of airflow limitation was higher in individuals who had ever smoked or been passive-smoker,[ 16 17 ] but was prevalent in never-smokers as well. Iran is a developing country where the smoking rate is lower than in many developed countries.…”

The Effect of Self-Care Training on Spirometric Indices in Patients with Chronic Obstructive Pulmonary Disease: A Clinical Trial Study

“…Approximately 5% of the world's population is affected by COPD, such that it was the third leading cause of death in 2012. The prevalence of this health problem is expected to rise to the extent that by 2020 it will be one of the top three causes of mortality in the world (2)(3)(4). Based on official statistics, an average of 14% of Iranians have COPD, varying from 0.4% to 1% across communities with different weather conditions (4).…”

“…The prevalence of this health problem is expected to rise to the extent that by 2020 it will be one of the top three causes of mortality in the world (2)(3)(4). Based on official statistics, an average of 14% of Iranians have COPD, varying from 0.4% to 1% across communities with different weather conditions (4). Due to its debilitating nature, COPD imposes direct and indirect costs to the healthcare system, society, and the patient (5).…”