Objective
To determine whether a modified Global Initiative on Obstructive Lung Diseases (GOLD) classification of chronic obstructive pulmonary disease (COPD) predicts mortality in a cohort of subjects followed for up to 11 years.
Methods
We analyzed data from 15,759 adult participants, aged 43–66 years at baseline, in the Atherosclerosis Risk in Communities (ARIC) study. All baseline and follow-up data were available for 15,440 (97.9%) of the initial participants. We classified subjects using a modification of the GOLD criteria for COPD (prebronchodilator forced expiratory volume in 1 s (FEV1) stratification of disease severity), and added a “restricted” category (FEV1/FVC>70% and FVC<80% predicted). We used Cox proportional hazard models to determine the risk of impaired lung function on subsequent mortality, after adjusting for age, race, sex and smoking status.
Results
1242 (8.0%) subjects died by the end of 1997. The overall rate of death was 8.9 per 1000 person years, but varied from 5.4/1000 among normal subjects to 42.9/1000 among subjects with GOLD Stage 3 or 4 COPD. After adjusting for covariates, all GOLD categories, along with the restricted category, predicted a higher risk of death: GOLD Stage 3 or 4, hazard ratio (HR) 5.7, 95% confidence interval (CI) 4.4, 7.3; GOLD Stage 2 HR 2.4, 95% CI 2.0, 2.9; GOLD Stage 1 HR 1.4, 95% CI 1.1, 1.6; GOLD Stage 0 HR 1.5, 95% CI 1.3, 1.8; and restricted HR 2.3, 95% CI 1.9, 2.8.
Conclusion
The modified GOLD classification system of COPD predicts mortality in this cohort of middle-aged Americans followed for up to 11 years.
- Lung function,
- Mortality,
- COPD,
- Smoking,
- GOLD classification,
- Cohort study
Available at: http://works.bepress.com/david_mannino/106/