TY - JOUR
T1 - Pre- and post-bronchodilator lung function as predictors of mortality in the Lung Health Study
AU - Mannino, David M.
AU - Diaz-Guzman, Enrique
AU - Buist, Sonia
N1 - Funding Information:
The authors thank the staff and participants in the Lung Health Study for their important contributions. The LHS was conducted and supported by the National Heart Lung and Blood Institute (NHLBI). This Manuscript was not prepared in collaboration with investigators of the LHS and does not necessarily reflect the opinions or views of the LHS or the NHLBI. The authors would also like to thank Ms. Susan Mittenzwei and Ms. Rebecca Copeland for their assistance in this project. The analysis and development of this manuscript was supported by a research grant from GlaxoSmithKline Pharmaceuticals.
Publisher Copyright:
© 2011 Mannino et al; licensee BioMed Central Ltd.
PY - 2011/10/12
Y1 - 2011/10/12
N2 - Background: Chronic obstructive pulmonary disease (COPD) is supposed to be classified on the basis of post-bronchodilator lung function. Most longitudinal studies of COPD, though, do not have post-bronchodilator lung function available. We used pre-and post bronchodilator lung function data from the Lung Health Study to determine whether these measures differ in their ability to predict mortality. Methods: We limited our analysis to subjects who were of black or white race, on whom we had complete data, and who participated at either the 1 year or the 5 year follow-up visit. We classified subjects based on their baseline lung function, according to COPD Classification criteria using both pre- and post-bronchodilator lung function. We conducted a survival analysis and logistic regression predicting death and controlling for age, sex, race, treatment group, smoking status, and measures of lung function (either pre- or post-bronchodilator. We calculated hazard ratios (HR) with 95% confidence intervals (CI) and also calculated area under the curve for the logistic regression models. Results: By year 15 of the study, 721 of the original 5,887 study subjects had died. In the year 1 sample survival models, a higher FEV1 % predicted lower mortality in both the pre-bronchodilator (HR 0.87, 95% CI 0.81, 0.94 per 10% increase) and post-bronchodilator (HR 0.84, 95% CI 0.77, 0.90) models. The area under the curve for the respective models was 69.2% and 69.4%. Similarly, using categories, when compared to people with "normal" lung function, subjects with Stage 3 or 4 disease had similar mortality in both the pre- (HR 1.51, 95% CI 0.75, 3.03) and post-bronchodilator (HR 1.45, 95% CI 0.41, 5.15) models. In the year 5 sample, when a larger proportion of subjects had Stage 3 or 4 disease (6.4% in the pre-bronchodilator group), mortality was significantly increased in both the pre- (HR 2.68, 95% CI 1.51, 4.75) and post-bronchodilator (HR 2.46, 95% CI 1.63, 3.73) models. Conclusions: Both pre- and post-bronchodilator lung function predicted mortality in this analysis with a similar degree of accuracy. Post-bronchodilator lung function may not be needed in population studies that predict long-term outcomes.
AB - Background: Chronic obstructive pulmonary disease (COPD) is supposed to be classified on the basis of post-bronchodilator lung function. Most longitudinal studies of COPD, though, do not have post-bronchodilator lung function available. We used pre-and post bronchodilator lung function data from the Lung Health Study to determine whether these measures differ in their ability to predict mortality. Methods: We limited our analysis to subjects who were of black or white race, on whom we had complete data, and who participated at either the 1 year or the 5 year follow-up visit. We classified subjects based on their baseline lung function, according to COPD Classification criteria using both pre- and post-bronchodilator lung function. We conducted a survival analysis and logistic regression predicting death and controlling for age, sex, race, treatment group, smoking status, and measures of lung function (either pre- or post-bronchodilator. We calculated hazard ratios (HR) with 95% confidence intervals (CI) and also calculated area under the curve for the logistic regression models. Results: By year 15 of the study, 721 of the original 5,887 study subjects had died. In the year 1 sample survival models, a higher FEV1 % predicted lower mortality in both the pre-bronchodilator (HR 0.87, 95% CI 0.81, 0.94 per 10% increase) and post-bronchodilator (HR 0.84, 95% CI 0.77, 0.90) models. The area under the curve for the respective models was 69.2% and 69.4%. Similarly, using categories, when compared to people with "normal" lung function, subjects with Stage 3 or 4 disease had similar mortality in both the pre- (HR 1.51, 95% CI 0.75, 3.03) and post-bronchodilator (HR 1.45, 95% CI 0.41, 5.15) models. In the year 5 sample, when a larger proportion of subjects had Stage 3 or 4 disease (6.4% in the pre-bronchodilator group), mortality was significantly increased in both the pre- (HR 2.68, 95% CI 1.51, 4.75) and post-bronchodilator (HR 2.46, 95% CI 1.63, 3.73) models. Conclusions: Both pre- and post-bronchodilator lung function predicted mortality in this analysis with a similar degree of accuracy. Post-bronchodilator lung function may not be needed in population studies that predict long-term outcomes.
KW - Bronchodilator responsiveness
KW - COPD
KW - Epidemiology
KW - Mortality
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U2 - 10.1186/1465-9921-12-136
DO - 10.1186/1465-9921-12-136
M3 - Article
C2 - 21991942
AN - SCOPUS:80053916345
SN - 1465-9921
VL - 12
JO - Respiratory Research
JF - Respiratory Research
IS - 1
M1 - 136
ER -