Table 1.

Total included studies and references by countries, WHO World regions. [31]and World Bank Income levels[36]

WHO Regions and income levels of included studies	High Income	Upper Middle-Income	Low Middle-Income	Region Totals	Included Countries	References
The Americas Region (AMR)	10	–	1	11	Nicaragua	[32]
					Canada	[37], [38]
					United States	[23], [26], [39], [40], [41], [42], [43], [44]
The European Region (EUR)	10	1	–	11	United Kingdom	[45], [46]
					Germany	[47], [48], [49]
					Spain	[50], [51]
					Israel	[25]
					Belgium	[52]
					France	[53]
					Georgia	[24]
South-East Asian Region (SEARO)	–	2	1	3	India	[35]
					Thailand	[18], [33]
Western Pacific Region (WPR)	5	1	–	6	China	[34]
					Australia	[54], [55], [56], [57]
					Republic of Korea	[58]
Global				1	Global Review	[11]
TOTAL Number of Studies	25	3	3	32