Factors associated with advanced COPD (% FEV₁<80).

<p>*indicates significance.</p><p><b>Model 1</b>: variables include age, height, weight, obesity, sarcopenia, and smoking status.</p><p><b>Model 2</b>: variables include FVC (L) in addition to variables included in Model 1.</p><p>FEV₁ (% predicted) was not included in the multivariable analysis due to the risk of co-linearity.</p><p>Abbreviation: Curr smk, current smoker; Smk amt, smoking amount; PY, pack-year; FVC, forced vital capacity; FEV₁, forced expiratory volume in 1 second.</p><p>Factors associated with advanced COPD (% FEV₁<80).