Fig. 2

Multivariable-adjusted HRs for all-cause mortality across GOLD and STAR stages. Adjustments were made for age, sex, body mass index, smoking exposure, use of inhaled corticosteroids, use of long-acting bronchodilators, history of asthma, and C-reactive protein level. As a result of a nonnormal distribution, smoking exposure was categorized into three groups: 0 pack-years, 0 < pack-years < 20, and ≥20 pack-years. C-reactive protein levels were dichotomized as ≥ 0.30 or < 0.30 mg/dL on the basis of their nonnormal distribution. Abbreviations: HR, hazard ratio; CI, confidence interval; GOLD, Global Initiative for Chronic Obstructive Lung Disease; STAR, STaging of Airflow obstruction by Ratio.