TABLE 2.

Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for the breath analysis and report analysis

Parameter	Breath analysis			Report analysis
	Expert	Nonexpert	p-value	Expert	Nonexpert	p-value
Sensitivity (95% CI)	0.20 (0.14–0.29)	0.21 (0.12–0.30)	0.837	0.10 (0.05–0.24)	0.10 (0.01–0.24)	0.915
Specificity (95% CI)	0.90 (0.85–0.93)	0.88 (0.79–0.93)	0.404	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.547
PPV (95% CI)	0.18 (0.12–0.25)	0.18 (0.11–0.23)	0.842	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.547
NPV (95% CI)	0.89 (0.88–0.90)	0.89 (0.88–0.90)	0.694	0.53 (0.51–0.57)	0.53 (0.50–0.57)	0.887
	Mask	Helmet	p-value	Mask	Helmet	p-value
Sensitivity (95% CI)	0.28 (0.17–0.37)	0.10 (0.05–0.16)	<0.0001	0.18 (0.00–0.36)	0.00 (0.00–0.00)	<0.0001
Specificity (95% CI)	0.91 (0.86–0.94)	0.86 (0.79–0.92)	0.008	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.555
PPV (95% CI)	0.30 (0.15–0.38)	0.07 (0.05–0.11)	<0.0001	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.553
NPV (95% CI)	0.89 (0.87–0.90)	0.89 (0.88–0.90)	0.271	0.50 (0.45–0.56)	0.55 (0.55–0.55)	<0.0001
	Europe	Asia	p-value	Europe	Asia	p-value
Sensitivity (95% CI)	0.23 (0.12–0.39)	0.20 (0.14–0.24)	0.176	0.13 (0.03–0.33)	0.10 (0.05–0.15)	0.114
Specificity (95% CI)	0.90 (0.78–0.93)	0.87 (0.84–0.91)	0.910	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.723
PPV (95% CI)	0.19 (0.10–0.26)	0.18 (0.15–0.22)	0.726	1.00 (1.00–1.00)	1.00 (1.00–1.00)	0.723
NPV (95% CI)	0.89 (0.88–0.92)	0.89 (0.88–0.89)	0.336	0.54 (0.51–0.60)	0.53 (0.51–0.54)	0.115