Abstract
Background: GOLD sought to standardize COPD definition and severity. The clinical meaning of GOLD 1 and it putative progressive nature remains uncertain.
Objective: To determine the characteristics of COPD GOLD stage 1 and it progressive nature.
Methods: This research is part of the Canadian Cohort Obstructive Lung Disease (CanCOLD), a prospective longitudinal study with a population-based sample of COPD. Subjects are recruited from 9 cities in one of 4 subsets (sex and age matched): 1) COPD GOLD ≥2; 2) GOLD 1; 3 and 4) non-COPD controls, i.e., at risk (ever smoker) and healthy. Measurements were done at baseline and 3-5 years later.
Results: This preliminary analysis included 111 subjects. GOLD 1 subjects as compared to GOLD ≥2 had less wheezing (20% vs 41%, p=0.048), physician-reported asthma (14% vs 41%, p=0.007), and better health status (SF-36): PCS (49 vs 46, p=0.191) and MCS (54 vs 50, p=0.002). GOLD 1 subjects were less likely to have a physician-diagnosed COPD (6% vs 17%, p=0.031) and to be prescribed respiratory drug (16% vs 38%, p=0.007). Subjects with GOLD 1 as compared to non-COPD control reported more dyspnea MRC ≥2/5 (39% vs 20%, p=0.082) but chronic bronchitis and level of health status (SF-36) were similar. Annual change in FEV1 were -62 ml/year (p<0.001) for GOLD 1, -32 ml/year (p=0.006) for GOLD ≥2 and -25 ml/year (p=0.18) for non-COPD. Annual change in physical health (SF-36 PCS) were -0.42 (p=0.086) for GOLD 1, -0.89 (p=0.023) for GOLD ≥2 and -0.20 (p=0.54) for non-COPD.
Conclusions: Early disease or GOLD stage 1 appears to be associated with more rapid decline in FEV1 and worsened health status.
Funding: CIHR Rx&D Collaborative Research Program; and the Respiratory Health Network of the FRSQ.
- © 2011 ERS