Fig. 3
From: Mucus plug and lung cancer incidence in patients with COPD

The association between mucus plug score with lung cancer incidence. Adjusted hazard ratios were calculated by controlling for covariables such as age, sex, smoking history, pack-years, Charlson comorbidity index, history of asthma, history of pulmonary tuberculosis, blood neutrophil (%), and post-bronchodilator FEV1/FVC.