COPD AND LUNG FUNCTION PARAMETERS AS PREDICTORS OF MORTALITY: THE PLATINO COHORT STUDY
It is know that low lung function and COPD can predict subsequent mortality in high income countries. The aim of this study was to describe mortality rates according to COPD and lung function in cohorts from three Latin American (LA) cities.
METHODS: A population based adult cohort was followed up in Montevideo, Santiago and Sao Paulo during 5, 6 and 9 years, respectively. The outcomes evaluated were: all-cause, cardiovascular, respiratory and cancer mortality; exposures were COPD and lung function parameters (FEV1and FVC). Cox regression was used in confounder-adjusted analyses. We also calculated sensitivity, specificity, positive and negative predictive values, ROC curves and Youden’s index.
RESULTS: The main causes of death were cardiovascular, respiratory and cancer. In the adjusted models including both genders, 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 combined. FVC did not show a significant association with overall mortality. For most COPD criteria sensitivity was low and specificity high. The area under the curve for FEV1was greater than for FVC for overall and cardiovascular mortality.
CONCLUSIONS: COPD and low FEV1 are important predictors for overall and cardiovascular mortality in LA.