. 2021 Mar 23;11(1):e12007. doi: 10.1002/clt2.12007

TABLE 3.

Predictive values of small airway function parameters (FEF_50%, FEF_25%–75%) combined with FeNO in predicting positive MCT in the discovery cohort

Characteristic Variables	AUC	95% CI	Sensitivity %	Specificity %	PPV %	NPV %	Accuracy %	+LR	−LR	p ^a	Variable coef.(p)	FeNO coef.(p)	Constant coef.
All (n = 534)
FEF_50% + FeNO	0.858	0.826–0.887	78.26	79.46	80.3	77.4	78.65	3.81	0.27	<0.001	−0.063 (<0.001)	0.042 (<0.001)	3.076
FEF_25%–75% + FeNO	0.865	0.833–0.893	82.61	76.74	79.2	80.5	79.59	3.55	0.23	<0.001	−0.071 (<0.001)	0.046 (<0.001)	3.435
≥55 years (n = 243)
FEF_50% + FeNO	0.851	0.800–0.893	80.47	75.65	78.6	77.7	78.19	3.30	0.26	0.002	−0.079 (<0.001)	0.047 (<0.001)	3.996
FEF_25%–75% + FeNO	0.844	0.792–0.887	85.94	71.30	76.9	82.0	78.60	2.99	0.20	0.001	−0.076 (<0.001)	0.048 (<0.001)	3.587
<55 years (n = 291)
FEF_50% + FeNO	0.865	0.820–0.902	79.05	83.22	83.0	79.3	80.76	4.71	0.25	0.001	−0.052 (<0.001)	0.040 (<0.001)	2.374
FEF_25%–75% + FeNO	0.883	0.841–0.918	81.08	81.12	81.6	80.6	80.76	4.29	0.23	<0.001	−0.071 (<0.001)	0.045 (<0.001)	3.592

Note: The cutoff values were selected by the Youden Index. Bold font indicates statistical significance.

Abbreviations: AUC, area under the curve; constant coef., constant coefficient of logistic regression; FEF_50%, forced expiratory flow at 50% of forced vital capacity; FEF_25%–75%, forced expiratory flow between 25% and 75%; FeNO, fractional exhaled nitric oxide; FeNO coef. (p), FeNO coefficient of logistic regression and it's t‐test for the p value; +LR, positive likelihood ratios; −LR, negative likelihood ratios; MCT, methacholine challenge test; NPV, negative predictive values; PPV, positive predictive values; variable coef. (p), another characteristic variables coefficient of logistic regression and it's t test for the p value.

^{^a}

Compared with FEF_50% or FEF_25%–75% alone.