Abstract
Rationale: There is evidence from high-income countries that low lung function and COPD predict subsequent mortality. Little is known about lung function as predictors of mortality in low- and middle income countries. Aims: To describe mortality rates according to COPD and lung function in cohorts from three Latin American (LA) cities. Methods: Prospective population based adult cohorts were followed up in Montevideo, Santiago and Sao Paulo during 5, 6 and 9 years, respectively. The outcomes included all-cause, cardiovascular, respiratory and cancer mortality; exposures were COPD (according to different criteria), FEV1 and FVC. Cox regression models were used in confounder-adjusted analyses. Sensitivity, specificity, positive and negative predictive values, ROC curves and Youden's index were calculated. Results: The main causes of death were cardiovascular, respiratory and cancer. In the adjusted models, baseline COPD was associated with overall mortality (HR 1.43 for FEV1/FVC<LLN, 2.01 for GOLD 2-4, 1.46 for the fixed ratio (FEV1/FVC<0.7) and 1.50 for FEV1/FEV6<LLN). For cardiovascular mortality, significant associations were found with GOLD 2-4 (HR 2.68) and with the fixed ratio (HR 1.78) for both sexes together but not among women. Low FEV1 was associated with an increased risk for overall and respiratory mortality in both sexes. FVC did not show a significant association with overall mortality. For most COPD criteria sensitivity was lower than specificity. The area under the curve for FEV1 was greater than for FVC for overall and cardiovascular mortality. Conclusions: COPD and low FEV1 are important predictors for overall and cardiovascular mortality in LA.
- © 2014 ERS