Table 5.

Results of ROC analysis of induced sputum cells in the discovery cohort

Discovery cohort	Eosinophil (%)	Neutrophil (%)	Lymphocyte (%)	Macrophage (%)
ACO versus COPD
AUC (95% CI)	0.708 (0.633–0.782)	0.271 (0.2–0.342)	0.433 (0.354–0.513)	0.660 (0.583–0.736)
Cutoff (%)	3.55	84.55	5.76	4.63
Sensitivity/specificity (%)	59.7/72.5	37.5/23.7	97/12	58.3/69.4
p-value	<0.001	<0.001	0.104	<0.001
Asthma versus COPD
AUC (95% CI)	0.673 (0.612–0.733)	0.234 (0.18–0.288)	0.393 (0.329–0.456)	0.746 (0.69–0.802)
Cutoff (%)	8.95	76.4	1.77	5.33
Sensitivity/specificity (%)	38.7/88.7	44.4/11.2	22.5/60	65.5/72.5
p-value	<0.001	<0.001	0.001	<0.001
ACO versus asthma
AUC (95% CI)	0.518 (0.438–0.598)	0.585 (0.508–0.661)	0.541 (0.458–0.623)	0.389 (0.312–0.466)
Cutoff (%)	1.11	70.66	1.64	7.16
Sensitivity/specificity (%)	84.7/25.4	69.4/50	34.7/76.1	36.1/43
p-value	0.668	0.43	0.33	0.008

Abbreviations: ACO, asthma–COPD overlap; AUC, area under the curve; ROC, receiver operating characteristic.