Table 4. Publication and study site profile of included studies.

Classification Criteria	Variables	Frequency (number of studies)	%
Publication year	1988–2000	3	6.8%
	2001–2010	13	29.5%
	2011–2020	28	63.6%
Country
	USA	24	54.5%
	Australia	9	20.5%
	Canada	3	6.8%
	South Korea	2	4.5%
	England, Italy, Japan, Portugal, Uganda, Taiwan (one study originated from each)	6	13.6%
Study setting
	Departmental level	22	50%
	Emergency Department	17	38%
	Radiology Department	3	7%
	Paediatric Department	2	5%
	Hospital-wide	18	41%
	Network-wide	4	9%