Table 1.

Definition of Spirometric States, Albuquerque, New Mexico, 2001–2015, Lovelace Smokers’ Cohort

	Smokers with normal spirometry	COPD GOLD stage I	GOLD Unclassified	COPD GOLD stage II+
Postbronchodilator FEV1/FVC ratioa	≥0.70	<0.70	≥0.70	<0.70
Postbronchodilator FEV1 percent predicteda	≥80 %	≥80 %	<80 %	<80 %

Abbreviations: COPD Chronic Obstructive Pulmonary Disease, FEV ₁ forced expiratory volume in one second, FVC forced vital capacity, GOLD Global Initiative for Chronic Obstructive Lung Disease

^aPostbronchodilator FEV₁/FVC ratio was based on the GOLD criteria [4] and percent predicted FEV₁ value was defined by the third National Health and Nutrition Examination Survey or NHANES-III reference equations [15])