2. Accuracy of chest ultrasonography and supine chest radiography for diagnosis of pneumothorax (patient level analysis).

Test	Studies	Patients (cases)	Sensitivity (95% CI)*	Specificity (95% CI)*
Main analysis: comparison of CUS and CXR
CUS	9	1271 (410)	0.91 (0.85 to 0.94)	0.99 (0.97 to 1.00)
CXR	9	1271 (410)	0.47 (0.31 to 0.63)	1.00 (0.97 to 1.00)
Difference			0.44 (0.27 to 0.61), P < 0.001	−0.007 (−0.018 to 0.005), P = 0.26
Subgroup analyses
CUS: type of trauma
Blunt	5	754 (223)	0.94 (0.86 to 0.98)	0.99 (0.97 to 1.00)
Penetrating & blunt	3	377 (114)	0.84 (0.76 to 0.90)	0.99 (0.94 to 1.00)
Unclear	1	140 (73)	0.85 (0.75 to 0.92)	0.96 (0.87 to 0.99)
CXR: type of trauma
Blunt	5	754 (223)	0.38 (0.19 to 0.62)	1.00 (0.92 to 1.00)
Penetrating & blunt	3	377 (114)	0.32 to 0.67	0.93 to 1.00
Unclear	1	140 (73)	0.75 (0.64 to 0.85)	0.99 (0.92 to 1.00)
Type of CUS operator
Emergency medicine	8	1192 (388)	0.91 (0.85 to 0.95)	0.99 (0.97 to 1.00)
Trauma surgery	1	79 (22)	0.82 (0.60 to 0.95)	1.00 (0.94 to 1.00)
Type of CUS probe
Linear	2	296 (89)	0.86 to 0.96	1.00 to 1.00
Curvilinear	2	362 (109)	0.98 (0.93 to 1.00)	1.00 (0.97 to 1.00)
Linear and curvilinear	5	613 (212)	0.84 (0.78 to 0.88)	0.98 (0.96 to 0.99)
Sensitivity analysis: only studies that blinded results of CUS and CXR between interpretations of each index test modality
CUS	7	1024 (304)	0.92 (0.85 to 0.96)	0.99 (0.97 to 1.00)
CXR	7	1024 (304)	0.49 (0.36 to 0.63)	1.00 (0.95 to 1.00)
Difference			0.43 (0.28 to 0.57), P < 0.001	−0.004 (−0.015 to 0.006), P = 0.42

CUS = chest ultrasonography; CXR = chest radiography.

*The range of sensitivities and specificities are presented where meta‐analysis was not performed because there were only 2 or 3 studies and a fixed effect for sensitivity and/or specificity was not appropriate given the substantial heterogeneity observed in ROC space. When there was only a study within a subgroup, the estimates of sensitivity and specificity and their 95% CIs are presented.