International Journal of Preventive Medicine (Int J Prev Med)2008-780251120141116143945ENTobacco Prevention and Control Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, IranChronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran,Tobacco Prevention and Control Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, IranBaqiyatallah Research Center of Gastroentrology and Liver Diseases, Baqiyatallah University of Medical Sciences, Tehran, IranOregon Health and Science University, Portland, Oregon, USA20141116<p><strong>Background: </strong>Chronic obstructive pulmonary diseases (COPD) are planned to rank fifth in burden of disease and third with respect to mortality by 2020. Carrying out research regarding different aspects of COPD is mentioned as important health priorities by academic institutions and governments. The burden of lung disease (BOLD) Initiative was designed a decade ago to develop robust models that can be used to estimate the prevalence and current and future economic burden of COPD. The goal of the present project is to describe the prevalence and determining the causes and risk factors of COPD in the population of Tehran city.</p><p><strong>Methods: </strong>This cross‑sectional study follows a stratified cluster sampling strategy with proportional allocation within strata. The target population is all noninstitutionalized inhabitants, aged 18-40 in one group and over 40 in another, who inhabit in Tehran city. The stratification of the sample according to the 22 municipal districts of Tehran is incorporated in the sampling process. Proportional to the number of households in the 22 districts, the appropriate number of clusters is weighted according to each district. For each cluster, a team of three members approaches the index household, which is specified through the aforementioned random selection of clusters, and continues the enumeration in 10 neighbor households in a systematic manner.</p><p><strong>Results: </strong>As a study protocol, there are no specific results to present; our purpose is to share our design with the scientific body.</p><p><strong>Conclusions: </strong>We expect that findings from the BOLD study in Tehran will show the status of COPD and its causes in the community.</p><strong>Keywords: </strong>Chronic bronchitis, chronic obstructive pulmonary disease, Iran, prevalence<span id="mce_marker">&nbsp;</span>http://ijpm.mui.ac.ir/index.php/ijpm/article/view/1442http://ijpm.mui.ac.ir/index.php/ijpm/article/download/1442/1724