Role of the Emphysema Index Combined with the Chronic Obstructive Pulmonary Disease Assessment Test Score in the Evaluation of Chronic Obstructive Pulmonary Disease

Figure 2

Receiver operating characteristic curve of the emphysema index (EI). The application of the EI to detect chronic obstructive pulmonary disease (COPD) has diagnostic efficacy, and the optimal EI cutoff value (EI = 16.2%) for distinguishing COPD from chronic bronchitis had the highest diagnostic efficacy when the sensitivity was 60.3% and specificity was 89.1%. Youden index = 0.494.