A population-based cohort study on chronic obstructive pulmonary disease in Latin America: methods and preliminary...

The PLATINO baseline study, conducted from 2003-2005 in five Latin American cities (São Paulo, Mexico City, Montevideo, Santiago, Caracas), showed a high prevalence of chronic obstructive pulmonary disease (COPD).

A follow-up study was conducted in three out of the five centers (Montevideo, Santiago, and São Paulo) after a period of 5, 6 and 9years, respectively, aimed at verifying the stability of the COPD diagnosis over time, the evolution of the disease in terms of survival, morbidity and respiratory function, and the analyses of inflammatory and genetic biomarkers in the blood. Some questions were added to the original questionnaire and death certificates were obtained from the national official registries.

The fieldwork has been concluded in the three centers. From the original samples in the PLATINO study phasei, we were able to locate and interview 85.6% of patients in Montevideo, 84.7% in Santiago and 77.7% in São Paulo. Individuals who could not be located had higher education levels in Brazil, and were more likely to be current smokers in Santiago and São Paulo than in Montevideo. The overall quality of spirometries was ≥80% according to American Thoracic Society criteria. The number of deaths was 71 (Montevideo), 95 (Santiago) and 135 (São Paulo), with death certificates obtained from the national mortality registries for 76.1%, 88.3% and 91.8% of cases in Montevideo, Santiago and São Paulo, respectively.

This study shows that is possible to perform population-based longitudinal studies in Latin American with high follow-up rates and high-quality spirometry data. The adequacy of national mortality registries varies among centers in Latin America.