Table 3.

Quality of evidence appraisal

OCEBM	GRADE	References
	2c	[14]
	2b	[15]
	1b	[16]
	2b	[17]
	2b	[18]
	1b	[19]
	1b	[20]
	2b	[21]
	2b	[22]
	1b	[23]
	1b	[24]
	2c	[25]
	1b	[26]
Level 3		[27]
	2b	[28]
	2c	[29]

Abbreviations: OCEBM = oxford center for evidence-based medicine, GRADE = grading of recommendations assessment, development and evaluation