Fig. 1From: Chronic obstructive pulmonary disease prevalence and prediction in a high-risk lung cancer screening populationCOPD severity as determined by low-dose CT according to GOLD classification by spirometry. Footnote to figure: -Due to small numbers, low-dose CT (LDCT) groupings of severe (n = 97) and very severe (n = 18) COPD were combined. -Weighted Kappa = 0.16Back to article page