Table 1. The characteristics of included studies.

Study	Plans of	No.	Pre.		LUS				CR
(Country)	CR		(%)	TP	FP	FN	TN	TP	FP	FN	TN
Bourcier JE[23]	Unreported	144	85.4	117	9	6	12	74	5	49	16
(France)				(95.1)			(57.1)	(60.2)			(76.2)
Testa A [22]	100% P	67	50.7	32	5	2	28	18	0	16	33
(Italy)				(94.1)			(84.8)	(52.9)			(100)
Reissig A [21]	100% P+L	362	63.3	214	6	15	127	213	11	16	122
(Germany)				(93.4)			(95.5)	(93)			(91.7)
Cortellaro F[20]	75%P	120	67.5	80	2	1	37	54	6	27	33
(Italy)	25%P+L			(98.8)			(94.9)	(66.7)			(84.6)
Parlamento S [19]	66%P	49	65.3	31	0	1	17	24	0	8	17
(Italy)	34%P+L			(96.9)			(100)	(75)			(100)

CR = chest radiography; FN = false negative; FP = false positive; LUS = lung ultrasonography; Pre. (%) = Prevalence of pneumonia. P = Poster-anterior; L = Lateral; P+L = Poster-anterior/Lateral; TN = true negative; TP = true positive.