The Platino project: Methodology of a multicenter prevalence survey of chronic obstructive pulmonary disease in major Latin American cities

Background: The prevalence of Chronic Obstructive Pulmonary Disease (COPD) in many developed countries appears to be increasing. There is some evidence from Latin America that COPD is a growing cause of death, but information on prevalence is scant. It is possible that, due to the high frequency of smoking in these countries, this disease may represent a major public health problem that has not yet been recognized as such. The PLATINO study is aimed at measuring COPD prevalence in major cities in Latin America. Methods/Design: A multi-country survey is being carried out in major cities in Latin America. In each metropolitan area, a population-based sample of approximately 1,000 individuals aged 40 years or older is being interviewed using standardized questionnaires. Eligible subjects are submitted to pre- and post-bronchodilator spirometry, and classified according to several criteria for COPD. Anthropometric examinations are also performed. Several risk factors are being studied, including smoking, socioeconomic factors, exposure to domestic biomass pollution, occupational exposure to dust and hospital admissions due to respiratory conditions during childhood. Whether or not subjects affected by COPD are aware of their disease, and if so how it is being managed by health services, is also being investigated, as are the consequences of this condition on quality of life and work performance. Results: At the present time, the study is completed in Saõ Paulo, Mexico City and Montevideo; Chile has started the study in March 2004 and it will be followed by Venezuela; two other metropolitan areas could still join the PLATINO project. Similar sampling procedures, with stratification for socio-economic status, are being used in all sites. Strict coordination, training and standardization procedures have been used to ensure comparability of results across sites. Overall 92% of the pre-bronchodilator spirometry tests fulfilled ATS criteria of quality in the three first sites (97% in Montevideo, 91% in Mexico and 89% in Sao Paulo). Conclusions: The PLATINO project will provide a detailed picture of the global distribution of COPD in Latin America. This project shows that studies from Latin America can be carried out with adequate quality and be of scientific value.